After reading my conundrum with my astrophotography equipment, I gathered what I had and looked for a solution.
Since I’m in no way able to afford a huge tricked out scope (we got a great deal on my 8″ LX10 on craigslist!) I’m sticking with what I have. Again, there’s a tracker on my scope but it is basically a barn door tracker. It is slightly more sophisticated though, it has a controller with “North, South, East, and West” buttons on it. As long as it is perfectly polar aligned (I’ll talk about this later) all I have to do is turn it on and it’ll automatically track whatever the scope is pointed at (this is typical barn door behavior) but if I want to drive the scope to look at something to the east, I hold down the “East” button on the controller, and it will DOUBLE the speed of the motor… making 1 revolution in 12 hours instead of 24. Wow right! Not so speedy. Well, it gets better. If I want to look at something West of my current object, holding the “West” button turns the motor off completely. The telescope then simply waits for the earth to spin until that object is within view. The North and South buttons work a little differently, the scope doesn’t move either of these directions unless a button is pushed. When it is, it turns on a motor that moves **Just as slow as the tracker motor.** It can also only move in a particular North/South direction until a screw on the mount bottoms out. This limits the number of degrees of rotation I can do North to South. Typically, I set it up so that when I start viewing, I’m in the middle of the screw, which gives me just as much leeway North as South, but halves the total amount I can move the scope in any one particular direction.
All this means that there’s no way I can whip this thing around to look at whatever I want automatically like GoTo systems do. I’ll have to unlock the clutches on each axis, then swing it manually to point at an object of interest, then lock the clutches down again and let the motors take over. I’m fine with that, but how do I know where things are in the sky? I’m not great at memorizing locations of stars and DSOs. My solution is to use a PushTo setup. A PushTo is for dumb telescopes. Basically, you attach it to your scope and it tracks where you are manually moving it to point. The best solution I’ve found for this is an app called Skeye. It is like google sky map, except it was designed so you can mount your tablet or phone to your OTA (Optical Tube Assembly… or Tube where your mirrors and lenses are). I’ll do a tutorial on how to setup and use this as well. For now, check out this guy’s setup.
So I can find objects in the sky, how do I take good photos of them? Due to budget (none really) I have to work with what I have, I first need to make sure that:
1. I am relatively well alighed with true North. (Not perfectly aligned, but close enough and I can do this quick and dirty).
2. I manually move the scope to point at what I want to look at. (This is easy enough).
3. Use a computer to automatically control the direction of the scope for long periods of time.
That last one is a doosey. And so that’s where my adventure began a few years back. I joined the yahoo support group for LX10 owners. Luckily, some of those guys have figured out different ways to hack together store-bought systems with their LX10s. Many of them were a bit too advanced for me (I don’t own a machine shop nor and I spending several hundred dollars on buying another telescope brand’s trackers and rigging it to my system in the hopes that I don’t fry it…) A guy named gt_keys had already been looking at a simple solution to connect an LX10 to computer-based guidance systems via an arduino connection. I like this idea because it can be used with multiple kinds of computer software.
The arduino hardware and code was developed by yahoo user gt_keys in Spring 2013. You can find his threads on the LX10 yahoo group; specifically, these files come from the files section. I’ll ask if he would put it on GitHub, or if he minds if I do so you can download it.
He has also developed a RaspberryPi version as well that seems to be more capable. Seeing as how the LX-10 is limited in the Dec and Right Ascension speeds, this arduino implementation will work fine for most things though you need to be connected to a computer of some type.
This requires a number of software packages to be installed:
So the hardware flow looks like this: You’ll have a USB webcam attached to your sighting scope which will feed data to a program called PHD Guider 2. See my post for how to attach a USB camera to your sighting scope. This must also have the ASCOM drivers installed which know how to talk to different telescope systems. Specifically we will need the “Meade Classic and Autostar 1” driver. (I can’t remember exactly which driver it is on the ASCOM site, but it is either this one or this one). This can be found in the settings menu of PHD2. I went through the “new equipment wizard” in PHD2 to create a group of settings for my equipment. Again, since the LX-10’s hardware is so limited, there isn’t much to enter really. There is no focus knob (though if you add one, gt_key’s arduino code seems to be able to handle it).
PHD2 will take the image from the webcam attached to your site scope and allow you to specify a particular star in the field. Once you begin tracking, PHD2 looks at how many pixels the star in your image has moved, then send the appropriate commands to move to the ASCOM drivers. These translate that command into whatever command your scope hardware requires. For instance, you might have an autoguiding Orion scope. There’s drivers for all of that stuff. In our case, the Meade LX10 doesn’t have a computer language, so gt_keys chose to use the classic Meade and Autostar 1 command set.
The ASCOM drivers send the message over your USB serial port to the arduino. gt_keys’s code reads in those commands and basically pushes the buttons on the LX-10’s hand controller electrically. The motors on the LX10 move very slow. It is literally a barn door contraption, moving a full 360 degrees in 24 hours, and if you want to drive the telescope the other direction, it just turns the motor off and waits for the earth to spin to the point you want to move to. This means that for you to get good long exposures or to track planets well enough, you have to get a relatively close polar alignment on your scope before you start. More on this in another post.
Firstly, build the schematic as shown. I used a green relay board from Seeed studios.
Secondly, before you flash the firmware to the arduino, you have to change a value to make the hand-held controller to work. This is on line 56. You must change “const int hcontrol = 0;” to “const int hcontrol = 1;” Otherwise you cannot test this thing unless you have it all connected up to the computer, getting ASCOM commands which are generated from the PHD2 program.
Other software and options:
How to guide mount PHD:
As an alternative to PHD Guider 2, (PHD2) you can try AstroTortilla. Though I’ve never tried it, here’s a tutorial for how to use it.
I have not tried these out, however I’ve seen them recommended several times. Comment and let me know if you love or hate any of these:
AstroImageJ is ImageJ for astronomy. ImageJ is a image processing program for scientific use that’s open sourced, Java-based and encourages lots of plugins, extensions, and macros to be built.
Astronomy.net can help calibrate your images through a web app. Really awesome to see other peoples’ shots as well. You can also have it pick out and name stars in images you upload. It is really cool. There’s a bot on reddit’s astro subreddits that automatically does this and posts the results if you submit images to that reddit. Here’s the bot’s feed and here’s an “Ask Me anything” AMA with the author. Oh, and the source code is completely open course too so you can hack on it if you want.
Jess and I have always wanted hardwood floors. We could afford the flooring material if it was on sale, but we couldn’t afford the installation fees. Being the lovers of DIY, renovate the bathroom floor ourselves. The product we chose was COREtec One which is a click-type floating floor that has a dense bamboo foam backing and a PVC top. The top of this material is stamped to give the relief of woodgrain. For an additional fee you can get cork added to the backing, but we cheaped out and have had great results, even on a concrete slab this flooring stays warm and is softer than tile or wood. It is industrial quality and has a 10-year commercial limited wear warranty. We tested our ability to lay COREtec flooring in a small upstair bathroom. The results were great and with the right tools and a little ingenuity it wasn’t very hard at all.
The first step was to remove the strip holding the carpet down to the linoleum and Lauan floor of the bathroom. I always hated these kinds of transitions. You must use a flathead screwdriver and hammer to uncrimp the metal to pull back the carpet so you can then pull out the nails holding the metal strip to the floor.
Then we used the removed the molding in the bathroom. Using this long-bladed utility knife, I scored the silicone caulk on the top and bottom of each piece of trim. Then using a prybar and hammer, removed the trim. I then had to pull up the carpet in front of the bathroom as well, so the hammer and a regular prybar were used there. We decided that in this particular bathroom, we’d leave the Lauan and linoleum and just place the COREtec on top.
We decided we’d like the boards to be long-ways from the entrance of the bathroom. One of the most important steps is to layout and measure first! Each box of COREtec has a limited number of patterns, so it is highly recommended that you pull planks from several different boxes to avoid repeating patterns too close together. With COREtec you don’t want to end up with a tiny sliver less than 2 inches wide as it won’t stay down well. We measured to see how many boards we’d need between the wall and the cabinet, then when we got past the cabinet, we measured wall to wall. We picked a number that would allow us to have at least 2 inches on every side. To cut the pieces long-ways (a process called ripping) I used my 60-inch bandsaw with a wood blade in it. A note on this… My bandsaw is advertised as a “(9-inch bandsaw” and all the documentation said that in big letters on the front. That means there’s 9 inches between the saw blade and the other side of the saw (in the center of the machine). But when I went to the local big box hardware store I realized that there’s no such thing as a “9-inch bandsaw blade”. The blades are labeled in accordance with their circumference. So my saw technically uses 59.5-inch blades. I recommend buying several of these as I broke a couple with all the cuts I had to do.
For smaller cuts, I used my junior coping saw/mini hacksaw. I recommend getting a few extra packs of blades for this guy as well. For our whole house, I went through one and a half packs of extra blades. This was really helpful for small notches or tweaks to cuts I had made on the bandsaw.As you can see in the pic, I am wearing kneepads. This is essential for floor work! The ones I have have a great snap for putting them on quickly. This is good because you adjust them to the right size once, then the quick snaps can be used to put them on and take them off without a lot of wasted time getting them comfortable again.
Using pencils to mark the wood-side of the COREtec, I used an uncut piece of COREtec as a straightedge to make sure I didn’t waver too much, then I cut it by hand ripped each piece by hand on the bandsaw. Then, using a carpet knife to score the coretec and the edge of the countertop to snap it, we were able to quickly cut some pieces to lay. Since COREtec is a floating floor, you want to leave a 0.25″ gap from each wall to allow for the house to settle without damaging the floor. We got a hardwood floor laying kit that had a block, pull-bar and spacers in it. Placing the spacers all between the COREtec and the wall, we began laying the floor. Since COREtec snaps together in only one way, be careful to measure and cut the board to have the correct side where you need it. I screwed up many aboard without triple checking this first.
You want to start laying the flooring if possible as those are the most likely to be straight. Most walls in homes are not straight. If you can’t start on the outside wall, start on the longest or with the right-hand side so you can clip the floor in to itself as you go. Place the spacers against the wall first. I found using cheap packing tape to keep them in place so they don’t move when you use the hammer and block to
We made our way across the floor until we got to the toilet.
Moving the Toilet:
The next step was to remove the toilet. So we turned the water to the tank off at the wall by turning the knob all the way closed and flushed the remainder of the water in the tank. There was still water in the tank so before disconnecting the hose from the wall, I grabbed a small plastic bucket to catch the remainder of the water from the tank. I also used this bucket to scoop out the remaining water in the bowl as well. I didn’t want that splashing around all over my carpet and subfloor. The next step was to remove the old bolts. This is always a pain because men piss inevitable piss on the floor and sides of toilets and the piss as well as humidity from hot showers will corrode the bolts and rust the nuts onto them. I had to get my Dremel out and buy some new metal cutting disks. The designers over at Dremel are brilliant with their design of the EZ Lock Mandrel for the cutting wheels. This mandrel allows the cutting blades to flex about the shaft a small distance without snapping. This was amazing to me as my whole life I’ve been breaking these stupid cutting wheels, finally someone designed the perfect solution to this annoying problem! If only they would solve the whole rusted bolts problem…. I digress. Basically, I used the Dremel to slice the nuts in half on both sides of the bolt, then used pliers to pry off that broken bolt part from each side, being careful not to ever apply pressure with the plyers to the porcelain. That can crack and ruin a toilet.
Once the bolts were free, I lifted the toilet and tilted it so I could clean the soft wax off the bottom before moving it into the hallway. Always be careful moving toilets. The tanks are bolted to the bowl and if you don’t pick them up from the base you’ll crack the porcelain and need a new toilet. The wax seals the porcelain toilet to the plastic PVC flange on the pipe in the floor to prevent poo water from leaking. . I highly recommend wearing gloves because 1. It’s where the poop goes and 2. the wax is incredibly messy. Once that wax gets on something, it isn’t coming off easily, including your hands. You can wash then 100 times and still feel it. And when you remove a toilet, use a wad of old towels or rags to stuff into the open sewer pipe to prevent too much sewer gas from coming up. We moved the toilet just far enough away to work in that area and places it on a plastic bag so it wouldn’t damage or get wax on the new flooring.
When you replace the toilet, you’ll need a new seal and new bolts. Buy these BEFORE you move the toilet. I hate the wax rings for toilets because you get one shot to put it on correctly, and you don’t really know if you did it right until weeks later when the floor is ruined from underneath from leaking poop-water. I prefer this foam gasket kit which comes with the new bolts you’ll need too. This replaces the wax, so use a putty knife (one you don’t really care about) to remove the wax from the toilet flange in the floor.
We made great time laying the new floor due to all the straight cuts and good measuring plan we had. The tougher part came when we had to cut the circular hole for the toilet pipe flange. My solution was to use the gasket I bought to replace the wax ring under the toilet as a template and laid the boards flat across the hole and traced the new gasket on the boards. Cutting the with the bandsaw was fast after that. Click in the last bit of flooring, whack the pull-bar a couple of times to make it cinch tight, and then remove the plastic spacers from the perimeter of the walls.
Install the new foam gasket and bolts on the toilet flange. It turns out that since we laid the COREtec on top of the Lauan and linoleum we had a perfect amount of space for this gasket to work with our toilet. Set the toilet on the bolts and tighten snug, but not too tight. If you overtighten the bolts, they’ll crack the porcelain and you’ll end up buying a new toilet.
If the gasket is too tall and your toilet rocks back and forth and you can’t tighten the bolts any more without risking damage to the toilet, then you have two options and I tried them both. You can buy toilet shims, which are plastic wedges you can shove under the toilet every couple inches to even it out. I didn’t really like this option as it didn’t support the entire toilet and if the gap was too small to hide the whole shim, I had to cut off the visible part with a utility knife. I scratched the floor pretty bad doing this and it still looked terrible. The better option is to buy or make a toilet spacer. I used scrap COREtec to build a toilet spacer by tracing the hole like I did before on some COREtec, but then after I cut the hole and put everything in place with the toilet on top I traced the outline of the toilet. Then I used the bandsaw to cut just inside the lines by about a millimeter or so. This made for a much more stable solution.
Either way you go, shims or spacer, you’ll likely have to clean up the look with caulk. Now some people (including me) say never caulk the base of a toilet in case there is a leak. But since I am using the foam gasket,I know there won’t be a leak. So I caulked around the edge of the toilet to hide the shims and the gap in one bathroom, and then to hide the edge of the COREtec spacer I made in the other.
Once finished, you must put the trim back on and caulk it, then figure out how you want to have the transition back to carpet in the hallway look. To nail the trim back on, you’ll need a nail gun. After researching extensively, I decided that an electric nail gun was easier and cheaper, but would not do a good job at all. So I had an excuse to buy this air compressor and this pneumatic air gun. I cannot stress enough how this tool changed my life. Using the nail gun, I finished the bathroom in literally about 2 minutes. In the past this type of thing took me about half an hour to do. The trick here is to make sure you’re using enough pressure to get the brads fully into the trim without the heads sticking out. If the heads stick out then you have to manually hammer them in with a nail set which is a pain. When nailing against a cabinet or a wall, you can angle the brands pretty much anywhere, into the floor to the wall but when nailing the trim by the tub only shoot brads directly into the floor, NEVER into the tub. It can crack your fiberglass or acrylic tub and that ain’t cheap.
After the trim is back up, use some silicone caulk (this stuff requires a caulking gun) to seal it back on the top as well as on the floor to make it water-tight. Use one of these caulk-spreading tools to get a nice consistent finish. Since COREtec is waterproof, you should feel confident about any spills or wetness on the floor.
Finishing the edge of the carpet is covered in another post.
This is a quick list of Equipment I have and what I want. I have yet to have the time to get any spectacular images yet, but I think I could get some good ones given some practice. This is mainly a list for myself, but in case anyone else is interested in what to get for starting out in astrophotography, here’s a reference point. My next post on this topic will likely be a description of how I plan to use this to take wicked pics of planets, nebulae, and hopefully some galaxies.
My next purchases:
In summer, I went to Woodcraft and grabbed a bunch of blocks of wood to make x-mas presents for some friends. I already had an idea of what I was going to make from a project video I saw on Inventables’s site. I wanted to make Passive Amplifiers that would double as a desk nameplate. Rather than use the pre-made file from Easel, I wanted to do my own in Fusion360 to get more practice.
Before I had any time to work on this at all, I ended up buying the new beefier gantry makerslide. I also 3D printed an enclosure for my smoothieboard and an enclosure for my E-stop button, both from thingiverse.
Literally at this point, I’ve got enough extra makerslide, plates, belts, ACME screw and nut set and gears to build a Shapeoko 2 (missing bolts, nuts, washers, V wheels, bearings, or idler wheels). Leave a comment if you are interested in purchasing my extra parts.
I also had beefed up my gantry motor to a NEMA 23.
Processing the Blocks:
Once I had made the changes to my machine (a never-ending project in itself) I got to work on the passive speakers. I clamped my handheld belt sander upside down in my workmate bench (I do not condone this stupid behavior). I sanded down all the blocks until you could no longer see the bandsaw marks using 150 grit sand paper. I rolled the edges and ends to get nice rounded edges. This worked for the most part, but sometimes I got inconsistent results along the entire edge of the block which looked bad and wasn’t easy to fix.
After rough sanding, I hand-sanded the corners to remove the sharp point using 150 paper by hand, then used 220 paper on my orbital sander to remove the traces of the rougher sanding and smoothed out the overall faces. Due to time constraints (I was so busy that I waited until the last minute to do these) I went ahead and hit the blocks with Tung Oil every other day for about a week. This soaks in and if I had done it more would really bring out the luster int he wood. It smells a bit funny so I left the blocks in the garage to air out. Tung oil is good because it won’t combust spontaneously like a lot of oil-based stains. Heck, the guy that sold it to me said he never even wears gloves and has been using it 20+years. I wore gloves anyway.
After the blocks were processed and thoroughly tunged, I went about using Fusion 360 to design the passive amplifier element. Unlike the inspiration project, I wanted a continuous spiral as my cone. I created a block approximately the size of these blocks, then I created a spring. It took a long time to figure out exactly how to get the spring to have the features and be be the size I wanted. I then had to merge this with a cone shape to create a single solid body that was a helical cone shape. I put it on the block and performed a difference operation to remove the helical cone shape from the block. Then I added the slot for the phone. I used my and Jess’s phones as tests using a block of scrap 2×4 to find a width that fit both of them.
I can’t say this was intuitive. When I ran simulations of the cut, I kept having weird errors that would break an endmill in the real world. For instance, the bit would circle the perimeter of the helical cone step by step, leaving a huge plug of wood in the middle 40mm high to be cut from the side at the very end of the job. In order to remove this weirdness, I had to get creative with the cuts. Firstly I used a plunge cut to cut the very center of the cone out in several passes. As you can see in the image at the top of this article, there’s a bit of an error at the right side near the top of the helical cone. This is due to the lead-in of the plunge cut. In later iterations, I removed that stupid lead-in. I have no clue why it would generate paths that would defile the user’s design, but it does…
Then I used a contour cut to remove material for the slot and helical cone in multiple passes. The Fusion 360 simulator said it’d take about 5 minutes for the whole shebang, but it took about 3 times longer in reality. I’m not sure how to reconcile this.
So I intentionally went against my best judgment on this one. Looking for a cheap engraving bit, I ended up at Harbor Freight. I found a pack of 5 HSS router bits that included an engraver for $8. Since an engraver bit is usually taking a bit more light duty use than other bits, this was a good deal. Other bits were like $25 just for the engraver elsewhere! My mistake happened when I considered using the half-inch router bit as an endmill. I figured if I take off only 1.5mm at a time, then it couldn’t hurt to use this router bit slightly out of its specified application. So I went ahead.
Surprisingly, this worked beautifully for the first four blocks I milled. The last one had ragged edges though. Since I needed to make about 4 more, I went back and bought another Hazard Fraught bit set. This was enough to cut the bulk of the gifts I was making. I had another 2 blocks to mill, but I had a couple weeks to finish those while these first 8 were needed literally that night at a party.
After I milled them, I had Jess get one of her fancy fonts and make some SVGs of our friend’s names to engrave on the other face of the block so it could be used as a nameplate on their desks. This was easy to do in fusion in a new file. I simply created a block the size of the wood I was using, then imported the SVG onto the face of the block. The Z axis here is still setup so the tool comes from the top (ie. as if the block has been rotated so that the face is pointing upward). Simply go into CAM and do an engrave and it’s done. The results came out beautifully!
The problems started when I moved my CNC machine the garage form the office to avoid the dust. I used one of those half-inch bits and aligned everything and let ‘er rip. I was making a video when the failure happened…
I hit the E-stop immediately but it still screwed up stuff. The bit came loose and slipped down as the router continued to spin (likely screwing up my quarter-inch collet) The CNC kept moving for a short time as well until I could hit the E-stop. This caused the bit itself to break. Luckily no chunks of it came loose or flew off at the 22,000RPM I was running at, but it came close as the pics below show.
After this error, I went ahead and redesigned the toolpaths to use a proper 0.25″ endmill and tried cutting another block. I didn’t get to see the final result, BUt I’m pretty sure the lead-in screwed me on the first plunge cuts I did. I didn’t finish the part because like a genius I stuck the vacuum cleaner hose in the way of the Z cart and ended usp causing my X axis motor to skip a bunch of steps as it wedged the vacuum hose into the block. I’ve yet to revisit this. even this short amount of exposure to the incredibly fine wood dust made my nose clog up again(even wearing a respirator). I had to go back to work after new years and haven’t had a chance to revisit (or document) and projects until now.
You can find them for as high as $600 for a hard-shell case or for a soft-shell case, about $300. We’ve had a set of luggage my mother gave us like 10 years ago and I repurposed the largest one to carry my OTA (telescope tube). It’s dimensions were perfect. 13″deep x 18″wide x 28″ tall. I went to a craft store and got some 1.5″ foam, wrapped it in a circle and smushed it into the bag. Then I cut off the excess which left me with enough to do a top and bottom and a sliver to set on the face of the tube after I lay it in there.
I did have to carefully cut a slot and hole in the top piece of foam to make a pathway for the focuser knob on the scope. This is the only thing I really worry about with this setup.
To make it look nicer and more finished, I got about 3 yards of shiny-satiny black soft fabric that I thought would be good to use and stuffed it along all the edges of the foam. I made sure to form the fabric into the slot and hole for the focuser knob. I don’t want that snagging or to have any weight on it at all. There’s no sewing involved, simply tuck in about 1 foot of material around every edge, leaving a long extra piece hanging out the bottom.
Once the tube is set in place, bring this excess fabric up, fold in the sliver of left-over foam and set it on top of the OTA. Then zip up and you are ready to go. The bag has plenty of storage for accessories, although I do not keep my lenses in this bag.
I would like to get a hard-shell case for it, but with the types of luggage available, the hard shell is very thin and I worry that it won’t hold up over time, but something like this looks a little more beefy. I’ve been looking at Ross and TJ Maxx when I happen to go to those stores, but nothing there seems to be big enough.
My current solution for a dew shield is very low tech. I got a dollar store version of this metallic accordion-style foam insulated car window reflector. because it accordions down to a small size and fits perfectly in my telescope’s bag. I attach it to my scope with a single 7″ diameter elastic headband. It works great!
I’ve been interested in astonomy my whole life, and a few years back, I got a second-hand Meade LX-10 telescope. This is a 8″ diameter scope… definitely not a toy. It is great for planetary viewing and can even track the planets as the Earth turns. I have used it from time to time to try to take some pictures of celestial objects, but not very good ones. Astrophotography is a growing interest of mine now and I found the learning curve quite steep. I’m throwing together everything I’ve learned over the past couple of years including links to software and such into a few posts. There are multiple steps involved in this project and it took me a long time, working here and there and amongst about 1000 other projects, to finally get everything together for this.
To take amazing amateur astrophotography images you need to decide whether you want to look at deep space objects (DSO) like galaxies or nebulae, or if you want to focus on planetary viewing (within our own solar system). You don’t really want to zoom very much if you want DSO images because zooming narrows your field of view and most DSOs you want to get are very dim so you don’t want to zoom in to make their light spread out across your eye or camera sensor too much, you want bright pictures. You can take some amazingly cool pictures with just a DSLR and a “barn door” tracker. (This is just a device that rotates counter to the Earth’s rotation so your camera will continue pointing at the same object for minutes or hours at a time, meaning it moves a full 360 degrees in 24 hours).
In my case, I want to do a little of both planetary and DSO. So I have my LX-10 telescope, which has an 8″ diameter mirror, meaning it can collect a lot of light, and it has a tracker so I can point a camera at one point in the sky as long as I want. However, unless you perfectly align the scope with true celestial north, the scope will still drift a bit over the night. This is because it is an open control system. You just point it at a star, turn it on and hope you aligned it well when you started. The best images are taken with closed-loop control systems. That is, they continuously look to see if it is drifting off target, then takes actions to move back on target when needed. This guy has my telescope and has taken some amazing pictures of planets, sunspots, and DSOs. Some are mindlbowingly good! To be fair, he’s using some reducer lenses like this one to change his F-stop to make it much quicker (for example F/3.75 and F/4.6 in some images), oh and he’s using a 4x Powermate lens a lot which costs as much as I spent on my entire telescope… But what is great about his site is that he tells all the settings he used for the images. This is similar to Reddit’s astrophotography subreddit.
My scope is what they call “slow,” “long,” or “dark.” This refers to the F-stop number. This is also called the focal ratio or relative aperture. It is a ratio of the len’s focal length and the diameter of the scope. THe focal length of my telescope is 2000mm. And the aperture is 8″ or 203mm. The F-stop of this would be about 2000mm / 200mm = 10. So this means my scope is a F/10 lens. The higher the f-stop number is, the darker the image will be (all other things being equal) when compared to a lens with a smaller f-stop number. For example an F/4 is considered a pretty “fast” telescope. My F/10 number basically means that to take a nice bright picture of Jupiter for instance, I need to play with the “sensitivity” or ISO number of the camera sensor (used to be film) as well as the duration I leave the shutter open on the camera.
You might say, “Well I can just crank up the sensitivity then. Higher sensitivity will make the image come out brighter, right?” The answer is yes and no. You can raise the sensitivity, but then a lot of other things (such as heat) can trigger a pixel to register a value in a digital camera. This will increase the noise in the image, making it staticy.
You might then think “Ok, the other option is to just open the shutter for a long time, exposing the camera sensor to more light over a longer time period.” yeah… not really. This can work as well, however you will increase the overall light pollution in your images and worse, you risk blurring the image. Since the Earth keeps on spinning, objects in a fixed telescope’s field of view move. Without tracking perfectly, long exposures will be blurred.
Even if you can fix all that, there’s blurring you simply cannot fix. This is due to heat inversion in the air column between you and the object you are viewing. The Hubble space telescope was designed to fix this problem… by simply being above all the air on earth orbiting in a pretty high orbital plane (at the farthest reach that the space shuttles could fly). Air at different temperatures has different densities. This acts like a prism to bend the shape of a beam of light. Look at a straw or pencil in a glass of water. Notice how it looks like it’s broken in half at the interface of the water and the air? That’s an example of the different densities acting like a prism. Since air is, well, air… it is gaseous and mixes and moves around a lot. It is in constant motion (unlike the water in your glass compared to the air sitting on top of it.) Hot air rises and cool air falls, making all sorts of weird prism effects in our viewfinder. In the column of air between you and the top of the atmosphere where Hubble is, there’s also a lot of dust. The dust as well as the temperature inversions is what makes starts look like they are twinkling.
Side note: Planets don’t twinkle in the sky when viewed by eye. This is because a star is so far away, you are only seeing it as a point light. This makes it easy for dust or temperature inversion to affect your view of it. But planets are much closer, and their light is spread slightly wider across the retina in your eye. This means there much less of a chance that a mote of dust will block it, or temperature inversion will guide the light too far from your retina.
So how do you fix the problem of having a dark image from the telescope without getting errors from too high of a sensitivity setting or blurring from too long an exposure and temperature inversions? You can thank Woz for the home computer! Using a laptop, I’m going to connect a closed-loop control system to my computer to track the objects I want to image very closely, reducing blur of long exposure images. I’m also going to take multiple images of the same object, then do a process called “stacking” where a computer algorithm will take the sharpest views of different parts of the planet, for instance, and stitch them together into a composite image that is overall much sharper. Then I’ll be able to do some image processing on the composite image to get some great results. Stay tuned for more posts on this theme!
It has been bout a year now since I last had a chance to play with my CNC machine, so I figured I’d give an update on the progress so far and what I’ve learned.
Firstly, I got the Dewalt 611 router and router mount. This is a huge upgrade from the no-name dremel knock-off I had. After test cutting just once with the old router, the brushes were shot. I sprung for a real tool instead of a toy. As a bonus, it makes the machine look nicer as well. In order to fit 1/8″ shank bits, I had to get a 1/8″ collet for the DW611. This wasn’t terribly expensive if you compare the cost to replacing all of my router bits with 1/4″ bits. I got all of this late summer 2015 and literally had only enough time to attach it all to my machine before life got crazy busy. I never even had a chance to test it until now.
I also recently got the Suck-It from kickstarter. This goes a LONG way into keeping dust to a minimum. A warning, however, I tightened the screw too tightly on my Suck-it and accidentally drove the bottom edge into one of my makerslide rails since I don’t have endstop switches. This promptly shattered the Suck-it acrylic into incredibly sharp shards. While you can purchase additional parts from the Suck-it website, I opted to make my own replacements from wood, which is a bit more forgiving.This also gave me a great chance to finally learn some CAD software.
While testing, I finally realized that the ACME screw inventables sent me last year as part of my upgrade kit is warped. It binds in a couple of places when I try to move the Z-axis up all the way. I thought that I could fix this by simply getting a stronger motor, so I ordered the NEMA 17 from inventables. This was stronger, but still couldn’t overcome the bend in the screw. The bend also causes the very tip of my bits to wobble ever so slightly. It is almost imperceptible, but makes a big difference when I mill multiple passes of the same shape or try to do PCBs.I contacted Inventables and Mo in customer service worked with me over a couple of weeks to get my Z working great. It turns out that Since I upgraded from Shapeoko1—> Shapeoko2–> Xcarve, I had the wrong spacers on my router mount. The ones I had were about 2mm too short. Mo helped me get the right length spacers (9.5mm long) and bolts(35mm). My short spacers and bolts were causing the ACME screw to bend back towards the gantry at a significant angle. When installing the new spacers, be sure not to use washers as this will also change the angle of the ACME screw. With the new spacers installed I can get all but 7mm of my Z axis working perfectly smoothly. Thanks Mo!
I also bought this clear tube for my suck-it vacuum mount. This was about 63mm in diameter, so I had to same the interior of the acrylic suck-it plate to fit the tube. I also cut it to about 9 or 10 inches in length. At this height, the tube is about the height of the router itself. This gives me more visibility to see what is going on with the business end of my router rather than the black coupling tube that the suck-it came with.
I wanted to learn a real CAD package since my FabAcademy training in 2014. I only had experience with Sketchup which, while very good for beginners, it doesn’t really follow the same kind of workflow as professional engineering CAD/CAM packages. I wanted to learn something along those lines. I had played with Creo, Solidworks, Antimony, and was looking into Rhino/Grasshopper when I saw Fusion 360. Autodesk has been going crazy buying and building awesome CAD/CAM tools for the hobby market as well as for industry. Fusion 360 is a complete engineering tool that can start with a 2D sketch or a 3D body and allow a user to create objects, render them realistically, stress test them with finite state analysis, and export 3D print or CNC toolpaths. Oh, and did I mention that it is free and has a very active community online as well? So I downloaded it and gave it a try. I am quite pleased with it in all respects!
Having no formal training, I opted to take some free online courses from Udemy.com. Check out my other posts concerning that. Of course, as with anything, beginning is the toughest part. It took me a couple of days to get the hang of the Fusion 360 workflow, but with all the great tutorials and videos online, it is easy to find answers to your questions. If not, you can post to Autodesk’s forum for help.
Moving on, I played with Fusion 360 starting with the 3D sculpt method at first to get some awesome organic shapes, then moved to learning the 2D sketch workflow. I measured my machine and aluminum rails of the Suck-it. I made quite a few mistakes along the way, and had to start over several times, but I finally figured out how to get what I wanted out of the software. It is still a bit buggy from time to time and crashed a few times when I tried to do certain things, but I think it was partially due to a bad design. I watched a couple videos and fixed my design and was able to create the toolpaths without further issue.
Fusion 360 can do 2D and 3D milling jobs with ease. There are a lot of options, but videos mentioned in my previous post cover most of what you need to know. I’m running a smoothieBoard on my machine and Fusion 360 has a CAM processor script designed for my board, so I simply select “Smoothie” from the dropdown menu when I go to export my design and I’m good to go.
Sending the job to the machine:
The main software people are using to send jobs to the smoothieboard is Pronterface, which is typically used for 3D printing. It’s all Gcode, so it doesn’t really matter, but for some reason, I didn’t like using a 3D printing software for CNC. Last year I tried using Universal G-code Sender with the smoothie and even played with coding in this ability, but life got too busy for me to continue, so I stuck with using Pronterface. What I like about Pronterface is the ability to create custom buttons. For example, I made buttons to zero the axes, reset the smoothieBoard after I hit the killswitch, etc. These prevent me from having to manually type the Gcode in the command window. I can even send smoothie console commands using these buttons.
You can also run the smoothieboard over ethernet. You can do so through pronterface or by using one of several web interfaces (meaning you can control your 3dprinter or CNC machines over the web). This is useful in my FabLab at work where we have a lot of 3D printers running on a 3D print server. You can run the smoothieboard on this as well. It can host several different web interfaces which I hope to go into later, but one of them is basically a webpage that looks just like pronterface.
I feel like I finally have a good workflow here. You can see my results here. I made replacements of the broken acrylic pieces of my suck-it dust boot that I made in Fusion 360. I used scrap wood, so it had quite a few drill holes going all the way through it already. I also did conventional only, and no climb milling which would have given a nicer finish. I used a 2-flute straight 1/8″ but as well, no spiral which would have also given me a cleaner result. Due to my learning curve, I did have to do some manual touch ups to the dimensions of the pocket which explains the nastiness in there you see.
With the impending arrival of Baby A, I have been busy crafting up a storm. There is nothing like the drive to get a nursery ready to serve as a great excuse to do all those craft projects you’ve been letting sit on the side burner.
This was one of my latest craft projects and it was one of the easiest. I’ve seen it pinned so many times and I’m sure you have too, but I wanted my own version nonetheless. I used my KNK Zing to cut out the Alphabet letters, but you can just as easily buy pre-cut letters (or stickers) in two or three colors to stick on yourself. I used three colors/designs total – blue for the majority of the letters, a heart design for the “I” and “U”, and pink for the heart.
Here is how it turned out:
I used a canvas frame I purchased at Michael’s on clearance for $7 and three pieces of scrapbook paper on sale for fifty cents each. This puts the cost of my nursery pizzazz at $8.50. I already had glue dots on hand, which I used to adhere the letters to the canvas. It is not a permanent solution, which I liked, because I can see myself reusing this canvas frame for a different purpose in the future (like many years in the future, so I’m not planning on changing it up any time soon).
Have you made ABC art like this before?
P.S. Yes there are random paper butterflies in this picture. They are part of a future project!
Many designers use some kind of computer-aided design or CAD software to make 2D and 3D designs. A common one used by many people is Rhino (especially when used in conjunction with the Grasshopper plugin). Fusion 360 is a newer, easy to use, free complete CAD/CAM package. If you are going to learn any CAD software for practically any purpose (designing, engineering, fabrication, rendering realistic models, etc) it should be Fusion 360.
Fusion 360 is an Autodesk application that can do many useful things for designers. Whether you want to do something as simple as making cool looking 3D models to stress testing (finite element analysis) and even simulating the simple physics of designs and even milling them out or 3D printing them, Fusion 360 has you covered. It can also render realistic materials and surfaces and make animations of your working mechanical devices. Did I mention that it is free and there are tons of free online video tutorials and classes showing you how to use it with example projects? Oh, and so you aren’t reinventing the wheel (or other simple hardware) you can bring in models directly from McMaster-Carr who carry all sorts of nuts, bolts, gears, chains, etc. which can save you loads of time. This is my brain dump for getting started with Fusion 360 and using it with my CNC machine and my wife’s 3D printer.
Download Fusion 360 for free license. They have yearly licenses for hobbyist and I think even small business, or you can get a 3 year license for education.
Learning to use CAD:
At this point, there are two methodologies to use when creating parts in Fusion 360. If you have CAD experience already, you might be more comfortable drawing 2D parts then extruding them into 3D, etc. If this is you, then check out this free training class. The second methodology is sculpting. It begins with simple 3D shapes you can manipulate almost as if it were made of clay. This is great for 3D smooth shapes. Check out this great free training class for this methodology after taking the first section of this class. These two methodologies don’t replace one another, rather they compliment each other. You will eventually need both for complex designs, but start with whichever one is easiest for you so you can progress quicker. I personally love the “sculpting” mode.
Since on a CNC machine, the Z axis is the one you attach the router to, you will need to change the position of the Z axis in Fusion 360. Then set your preferences such that Z axis is the top axis. Within Fusion 360, click your name at the top right->Preferences. In the main window that pops up, about half way down, there is a “Top Axis” option that is set to Y, change this to Z and then “Apply” Now Z is the top axis like on your CNC machine. This will work for all NEW documents, but if you happen to have an older design or are importing someone else’s design, there’s a couple different ways to change the Z axis. The simplest method is to select the up-axis when you “setup the job” in Fusion 360. This is done when you are finished with your model design, and want to start creating the toolpaths.
Now, get into making some stuff. While Fusion 360 can do 2D and 3D designs and generate toolpaths for the CNC machine, there are lots of simpler (dumber) 2D workflows out there that are great such as Makercam.com or Easel from Inventables, etc. I’d use Fusion for more complicated 2D and 3D designs. For example, Easel won’t allow you to use a chamfer bit or V bit for engraving last I checked, but Fusion 360 will. This can make some amazing 2D designs.
You will notice that some of the videos tell you to delete certain lines in the generated Gcode from Fusion. This is mostly because it adds a “home” command and many DIY CNC machines don’t have homing switches. This command might tell your machine to go to the maximum extent of your machines to find the switches, but since you have no switches, it’ll end up messing up something. So many of the tutorials suggest removing the G28 (home) line from the Gcode Fusion 360 generates. If you have a smoothieboard controller, you should be fine to leave it in as long as you have set up your config files correctly.
How to set your origin to a different are of the design for milling. The best setup is one like the Othermill uses which ensures you never cut into your spoilboard. “Don’t spoil the spoilboard” is a great explanation of this method. I hope to make vids on how to in fusion 360 and real machine.
Can export to Othermill, or Smoothieboard, pocket NC, or other mill. Tons of options in the “Post Processing” menu.
You can simulate the milling process. When you do, the paths have different colors. A post on Autodesk’s forum cleared up what they mean:
Here’s my video of an example project I made. It is full of tips on stumbling blocks I came across.