Painted Subfloor is Acceptable

In both of our houses, the Master Bedrooms had pet stains that were  left by previous owners. This caused our pets to mark those same spots. To stop this behavior, we found a couple solutions. Once we removed the offending carpet and sealed the subfloors upstairs with Binz to seal the pet odors forever. We couldn’t afford to recarpet yet. So we did the next best thing. We just picked a color of paint we had a lot extra of and threw it on the floor.

 

 

 

 

FIrst we levelled the floor a bit and sealed cracks with wood putty, then just painted. We kept the room like this for some time as it was a creative space, almost a art studio feel. When we could afford it, we of course did finish the floor (more on that later). But it worked great in the meantime. The sub floor wood chip pattern worked to break up the color of the paint and gave a carpet-type look. It does soak up a lot of paint, so you might want to hit it with a primer first.

Gratuitous texture closeup:

Patching a Large Hole in Drywall

I friggin’ hate drywall. But when you like in paper mache houses like we have in the US, you have to deal with it. I can’t tell you how many crappy patches I’ve had to do in the past (when we moved into this house there were so many holes punched in doors and walls from the previous owner!)  I especially hate large holes in drywall because there never seemed to be a good way to plug them without some kind of support from inside the wall. Then I found this method on some random video and have been using it ever since.

The first step is to standardize the hole. This sounds dumb, but you have to cut a slightly bigger hole in the wall. The trick is to make your hole a simple shape with straight sides. Triangles and rectangles work well for this.

hole     squareHole

The next step it to get some patch material. You can get a 2” x 2” piece of drywall form any big box hardware store.  Measure the hole you cut in the wall and cut out a piece that is a couple inches bigger on each edge. ie. a 5”x 5” hole should get a patch that is 9” x 9”.

patch2

Here’s the trick! Cut the outside dimension completely through, but only score the actual hole size lines on your patch.

patch4

Then remove the edge pieces being careful not to tear off the facing paper.

patch5    p6

Test fit this patch to see that it fits your square hole.

squareHole         pat7

Remove the patch and liberally apply mud to the edges of the hole and the edges of the patch.  You will need mud on both of these!

mud1     mud2mud3

Stick the patch back on the wall and flatten it out with a large putty knife.  This may take a couple of cycles of mudding, drying, sanding, and mudding again until it’s all smooth.

mud4

When you are done, paint the wall. This was in my garage so there wasn’t a big need to do it, but we had been planning to paint anyway. Painting the garage is the actual reason I needed to patch this in fact.

DIY Bent Plywood Guitar and Ukulele Holder

I’ve had the materials for a couple of years to do a project just like this, just never got around to it. When I came across this guy’s website and video tutorial making a bent laminated guitar holder, I had to give it a shot.

You’re most familiar with flat plywood, but plywood can be made in all kinds of shapes. The famous Charles and Ray Eames designers showed the world how far plywood could be bent to their will (yes… yes I just wrote that, sorry).

To make bent plywood, there’s a variety of methods, but typically you have at least one mould made from wood, metal, or MDF. Then you’ll use very thin sheets of wood called veneer. Coat the wood with glue and lay multiple layers on the mould and apply pressure until the glue dries. To apply pressure some designs use a positive mould and a negative mould and sandwich the veneer sheets between them. You could also just use clamps like the guy in the the links above, or you could do what I did and use a vacuum bag to get the pressure of the atmosphere to get in all the nooks and crannies.

I don’t have a real vacuum bagging system, not that you have to spend too much to get one.  I already had a Ziploc food saver vacuum sealer  I’d never used.  It came with 3 small bags to get you started, and I only used one.

My first inclination for making the mould was to use my Xcarve CNC to mill out the design, but I’m kind of pissed off at my CNC workflow right now so I skipped this.  It is much faster to just cut some MDF by hand.  I started by cutting a template for the design out of cardboard to test the angles and lengths I would need. I then traced the side profile of the design on some MDF and cut it out on my bandsaw. I needed the mould to be about 3 inches wide so I cut 4 of these rough designs and glued and clamped them overnight.

The next day, I cut the now solid block on my bandsaw. This didn’t go as planned because my bandsaw blade wasn’t tight enough (I think) and I ended up with a not consistently 90-degree edge on my critical radius of the mould. This meant I’d have to do a lot of sanding to try to even it out.

 

I mounted the mould in my workmate and went at it with the beltsander. Of course always wear a dust mask working with wood, and at least a half-face respirator with NIOSH100 particle filters (NOT just vapor filters!) and goggles when working with MDF. (Reference from someone who knows a bit about safety). MDF is a blend of sawdust and god-knows-what nasty chemicals in the glue.  Limit your exposure to it, and try to be in an outside environment. Attach a shop vac to your tools, clean up any dust in the shop and be sure to run your HEPA filter to clear the air of particulates for any MDF work or and fine sanding, etc.

Once I got the approximate lengths from the mould, I cut the veneer.  I had 12 square foot pack of Sauers & Company walnut veneer which happened to be about 6 inches wide.  I was able to fudge my measurements so that splitting the sheet in the middle on half of my cuts gave me two pieces I could use for a uke holder. Guitar holders will need to be wider and you’ll likely have a bit of waste when ripping with the grain. Keep these offcuts for other future projects though, seriously make a bangle bracelet or ring or something if you can’t think of anything else. I only used a single sheet from my supply which gave me enough material to make 2 uke holders.  When cutting, you should make sure you cut with the grain for half of the sheets and then across the grain for the other half. The criss-cross grain gives plywood its flexibility and strength.

I used an exacto blade to cut my sheets. I ended up with 8 sheets total which measured roughly 5.5″ x 2.75″ each.  Again, 4 sheets had the grain running longways, the other 4 had the grain running their shortest dimension. This veneer is somewhat fragile and liked to split in places I didn’t intend, so I had to be very careful with it and cut or score with a metal straight edge.

The sheets of veneer with the grain running longways did not want to bend around my form, so I did what any idiot would do and tossed them into a bowl of hot water first.  They immediately curled and I could no longer tell which side was the “good” side to show the best grain detail. This did allow the sheets to easily bend around my tight radiused curve on the mould without splitting or breaking though.

Since I was going to be making a giant mess with glue of any type, I’ve learned to lay down a good foundation of wax paper to protect my working surface (countertop in this case). TIp: If the wax paper wants to curl up and not lay flat, simply rub a wet rag on the counter first. the water’s tension will make the paper adhere to the countertop.  A note of caution. The glue will bead up and roll off this and spill all over the floor if you aren’t careful. so make sure to keep it contained.

I also covered my mould in wax paper to prevent sticking, but next time I’m just going to use Johnson’s paste wax. This stuff is good for just about every thing as well but works great for mould release in fiberglass and plywood projects, repels glues, protects wood, and won’t leave additional crease marks in your design like the wax paper can.

I took the nicest piece of long-grained veneer from the bowl of warm water and coated it with glue. This will be the inside piece, facing the user. Then I started layering all 8 pieces , applying glue between each layer and making sure to alternate grain direction each time. I also wanted to end with grain running length-wise so I saved the second best looking piece for this.

When I was done building the stack, I laid it on the mould, placed it in the vacuum bag and hit the “Vacuum and seal” button.  The Ziplock device sicked out all the air in about 20 seconds or so and during that time I frantically smoothed pieces and wedged them how I wanted.  When it is done, it heat-seals the bag.  I’m not going to lie, I had to cut the bag, reposition the stack and do it again. I was luck in that my mould was small and fit in the bag with some extra room. I cut it open straight across and reused the same bag.

This is how it sat for a full 24 hours which  thought was plenty of time. Heck, this guy built a longboard using vacuum bags and only let it dry 8 hours. I was having no luck with that. The glue was still just as thin as when I put it on there. So I called the woodcraft store and asked for advice. The recommendation I got was that putting the sheets in water to loosen up the fibers added way too much water to the situation. Honestly, I think it was a combination of that and the glue I used which was Titebond II extended wood glue, which was recommended to me by another guy at Woodcraft which takes longer to dry anyway. (I was originally going to use this pack of veneer to make acoustic guitar sides which would require a long working time for the glue).  Really though I can’t figure out how the glue is supposed to dry if it’s in an airtight container. Isn’t the bottle an airtight container and that’s why it’s not all solid when you buy it?  Where’s the moisture supposed to go?  Next time I’ll maybe throw in some desiccant packs under there to soak up the moisture from the glue. After more research, the moisture apparently soaks into the MDF.  Not directly because of the wax paper, but indirectly. There are a few factors that control the glue drying (depending on the glue or epoxy). One main contributor is temperatur. Using a heating pad or electric blanket is often recommended.

After a full day and a half with no change in glue consistency anywhere in the bag, I wrapped duct tape around the form tightly to try to keep its shape, then cut the bag open on both sides to allow the air in. After a day or so of additional drying time I cut it out.  I thought the wax paper wouldn’t stick to the veneer, but I was wrong. It stuck pretty good and I had a tough time peeling it off, so I ended up sanding it off. Also, the back side came out looking pretty good except it had the webbed texture of the vacuum bag in glue relief that I had to sand off. It also STILL hadn’t cured fully and it was still quite pliable, with the veneer separating if I tried to bend it. Looking at the angle of the holder, I realized that as it was, it would never be a good hook shape to hold the guitar given the mould I had and a little springback in the wood since it hadn’t fully cured yet. So I cut a half-inch dowel in half and stuck it in the crease and put the stack of veneers back into tension for another day. I clamped it this time and added some water-thin CA glue (superglue) to some of the loose veneers in the middle of the stack. I also had to superglue a few strips of veneer that just couldn’t handle the bend and had split.

After all this it was finally dry. I went about sanding it. Sanding interior radiuses is a nightmare, so do yourself a favor and but a nice round foam sanding block and make sure to never buy cheap sandpaper.  I used 3M cause I had it, but a rule of thumb is that almost any yellow (don’t use black) sandpaper with a P rating will be good. There are two different grit rating systems for sandpaper and the P rating is the european one. It has higher regulations and gives much more consistent results.  Also, 180P grip is not the same as 180 CAMI or just 180 grit You should be looking at the FEPA/ISO standard, which is the P rating. This is printed on the back of the paper.  And I recommended against black sandpaper because it it to be used in wetsanding metals typically. It is made of silicon carbide and can stain wood with carbon dust that will show up in your final finish if you aren’t careful.

You can see here how rough the hanger is at this point. You can also see some separated veneers. Again, i hit those with water-thin superglue which is great because it wicks its way into every crevice (again apply this on top of wax paper or you’re going to have a bad time…). I used small clamps to  hold these edges tight until it was dry. I actually waited overnight, but could have started earlier. You might want to get some activator for the CA glue to speed up the drying process. Even overnight when I sanded I could smell when I hit a pocket of wet stuff.

The pic below shows the hanger with the edges cleaned up on the bandsaw a bit in comparison to the cardboard template prototype. 

I laid out the decorative curves for the cuts on the bandsaw using sticky remnants of sandpaper as a guide. I cur one side, the traces it on some paper for the other side. It can never be perfect because the mould wasn’t straight and I can only cut so much off the edges since it is already pretty narrow.

I also used the bandsaw to cut the center notch for the actual instrument to hand from.  This was a bit of measurement then trial and error as I have several ukuleles of different neck widths and I wanted a universal hander.  I have to say tat due to the saw’s limitations and the extreme curve of the piece, I think I was able to get the best result possible. Sand again with 180P and 320P. 320 is overkill on the smooth finish, 220P is best for this, but I don’t have any on hand.

Here you can see the prototype cardboard with the final product. It;s a little wonky and twisted, but it will work.  Now on to finishing. The inspiration designs were all glossy, but I can’t stand a glossy finish on wood. Seems too fake and plastic to me. All my instruments (save for my electrics guitars which are painted) have a nice satin finish. This is also a test of the Wipe-On poly I’m using or the Ukulele kit I’m building. (More on this in a later post or series of posts i’ll likely forget to update a link here for).

The first coat of poly is a light sealing coat.  Wait until it completely dries and is no longer tacky, hit again lightly with the 320 and then do a heavier coat. Do this in a ventilated area, and be careful with the wrags you use. They will spontaneously combust as they dryl it’s best to lay them out flat on your driveway or in the yard until the poly cures hard on the rags, then throw them away.never store them in a pile in your garage or house or even nearby. Don’t believe me? Google it to see  many stories of people who were careless and now they are homeless.

Again,wear gloves when using chemicals, as well as well ventilated areas and safety glasses. You’ll do one thinner seal coat, let it dry then come back in a few hours and do a light sanding, and thicker coat Repeat once or twice more to your desired effect.  A satin poly will never be too shiny, so if you want that look, make sure you buy the gloss finish wipe-on poly.

 

On the very end results I added some foam padding with rubber cement to the edges of the hook as to not mar the ukes, and of course screwed it to the wall. Works and looks great!

 

 

Now was it work all the time and effort rather than just buying one?   Hell yea it was. Plus now I have all the materials to make as many as I want and get fancy with them with inlays and such. This one was a learning process. I already know what I’d like to improve.

          

PCB Milling Software Survey

FacAcademy had used a great tool designed in-house for PCB milling making it stupid easy.  I should be able to mill some PCBs at home right? Ha!

Method 1 Carbide Copper (web-based): Carbide Copper (Formally Rapid PCB)is by far the simplest solution for PCBs. A simple step by step process takes your Gerber and Excellon files and generates great g-code for your machine to run. Check it out below:

Method 2 Easel (web-based): Easel is the online CAM tool from Inventables, the makers of Xcarve. It has a lot of good settings in it and the interface is great. I just hate storing all my files online. Honestly I’m kinds sick of all these online “apps” that change settings and user interfaces elements all the time. Makes it impossible to follow a video tutorial after 6 months since nothing looks or works the same (looking at you AutoDesk!)

Method 3 FlatCAM: Once  you create your PCB, you need to run a CAM process inside your PCB tool (such as EagleCAD or KiCAD, etc) to export the gerber and excellon files of your design. Gerber files basically throw all bottom traces into one file, all top traces into another, all drill files into another, etc. Then to view these, you need a Gerber viewer.  Once you do that, you can use a CAM software to generate the tooling for making the board. This is where FlatCAm comes in. You import your gerber files and FlatCAM will help you create the path the PCBmill will need to move to create your circuit.  I must say, I found FlatCAm’s user interface frustrating. YOu bring in your gerber of the bottom traces for instance, then click another tab to set up the tooling, then that creates another file in your project in which you must then select and select another tab (again) to finally generate the g code for your machine.  You have to do the same with the top traces file, the drills file, and the dimension file. This seems convoluted and frustrated me.

Method 4 MakerCam: This method works well for Fritzing. You can export an SVG from Fritzing, then import that into inkscape for touch-ups, then on to MakerCAM to generate the final product.

Method 5 FabModules: The older linux-based Fabmodules won’t work for me, I’m not installing a bunch of junk on my PC just to run fab modules. Luckily, there’s a new web-based version at http://fabmodules.org  The new version doesn’t seem to be as good as the old version in creating the output files. Here’s a basic intro to making PCBs with it:

Method 6 Fusion 360: While the newest version of Eagle has a plugin to send the PCB design to Fusion360, you can’t do anything useful with it (such as extrude the traces easily). It seems you have to redraw or trace the traces onto a Fusion360 sketch. While using “Smart snapping” can simplify this, it’s still something that should be automated. (Correct me in the comments if I am mistaken about this method). However, a friend of mine worked out a method that seems to have worked well for him. You export the EagleCAD as an PNG, then import the PNG to fabmodules to create an SVG of the outline of the traces, then import this SVG into fusion and extrude and generate toolpaths.

The workflow is similar to the video above for the fabmodules. Once you bring your SVG into Fusion360, extrude all the traces up about 0.2mm (could be time consuming) and extrude the remainder of the PCB downward -1.5mm and select a teeny-tiny endmill. If you have to, simply create this as  a new tool. 1/64″ (0.39-0.4mm) is what FabAcademy uses typically. Then create a 2D contour around all the traces.

 

PCB Milling Tips

This post is like a scratchpad for documenting for myself the process, but could be helpful to you as well. To mill PCBs, I recommend the following:

Only use FR1 blank boards. FR1 is paper infused with fiberglass resin. This is better to mill than FR-4 fiberglass substrate boards. It is better on bits than FR4 and you won’t have tiny specs of glass dust in the air when you cut PCBs. You can get this at Inventables.com or Bantam (formally Othermill)

I had a bunch of issues generating a usable board. My workflow was originally to use EagleCAD to FlatCAM, then pronterface to control my smoothie board. I have since come across Carbide Copper which seems to be MUCH better.

Since my work are isn’t level, I attempted to level it before milling a PCB.  That didn’t work for… well.. reasons.

I then decided to autolevel the board. After MUCH research and trials and tribulations, I discovered that the smoothieboard has this feature built in to it’s CNC firmware.  You need to probe the PCB  to see where the surface is, and it will automatically record the offset in the Z axis and apply it to your G-code so you’ll have nice boards.

  1. First, place the PCB blank on the workspace using 2-sided scotch tape.
  2. Move the CNC to the 0,0 position and make sure this is the MACHINE offset (reset the smoothieboard once in this position).
  3. Build a probe (simply two wires with alligator clips as ends that plug into the Z stop.
  4. Scuff up the PCB’s surface with a scotch brite
  5. Use a piece of aluminum tape affixed to the PCB’s surface in a nondescript spot. Allow some of the tape to overhang enough to clip one lead from the probe to it.
  6. Clip the other lead of the probe on your endmill
  7. Make sure there’s good conductivity from the metal tape and the surface of the PCB, or else you’ll be buying new bits and might break your machine. 
  8. Knowing the dimensions of your board, and how resolute you wish to measure the surface, issue the following command:
  9. G31 X0 Y0 A75 B50 I7 J7

    This starts probing at X0 Y0, and goes to X75mm  probing 7 times along the way (I7).  It will then move 1/7th (J 7) in the Y dimension towards Y50mm.  It makes a zig zag like this across the entire board until it reaches the endpoint X75 Y50.  The number of probe points in each dimension (I and J) need to be odd numbers. An example of its results are shown below.

    50.0000|    -0.0986   -0.0920   -0.1032     -0.1336      -0.1647     -0.2448     -0.3930
    41.6667|    -0.0966   -0.0860   -0.0906     -0.1032      -0.1475     -0.1833     -0.1727
    33.3333|    -0.0582   -0.0476   -0.0463     -0.0774      -0.1184     -0.1667     -0.2335
    25.0000|    -0.0741   -0.0437   -0.0384     -0.0582      -0.1052     -0.1581     -0.2263
    16.6667|    -0.0364   -0.0099    0.0013     -0.0278      -0.0681     -0.1237     -0.1912
    -8.3333|    -0.0172    0.0139    0.0218       0.0053      -0.0337     -0.0886     -0.1661
    _0.0000|     0.0040     0.0291    0.0404      0.0139      -0.0086     -0.0655     -0.1389
    _________—–+———-+———-+———-+———-+———-+———-+—–
    _________0.0000     12.5000      25.0000     37.5000     50.0000    62.5000    75.0000

    (Thanks for the great spacing wordpress… just ignore the underscores) The numbers represent the offset from Z=0 at each point in the grid.

  10. At this point simply tell the machine to go to (0,0,0), remove the probe clips and tape (Seriously do NOT forget to do this… again).
  11. Load the gcode into pronterface, turn on the router on its lowest speed and run the file.
  12. Cuss a lot when something goes wrong.
  13. Contemplate creating your own all-in-one solution.

Another tip I saw online (Thanks pda3k!) was to use the Z probe in a single spot (this would be for other things, not PCBs.

New Z probe: T. Once it makes contact, it raises the tool to 19mm. G10 L20 Set Coordinate System
G30 Z9.6
G10 L20 P1 Z9.6 ;G10 L20 Set Coordinate System in P1, he touch plate is 9.6mm thick
G0 Z19 ;it raises the tool to 19mm.

Although OpenCNCPilot looks like a very nice project with autolevelling and camera integration… Maybe I’ll use this to help visualize stuff better. Thought it likely won’t work with the smoothieboard. We’ll see in the future post.