Because I apparently don’t have enough projects, I decided that I needed to rebuild my ShapeOko using the newly designed motor mount plates. 🙂
The new plates are stiffer (maybe thicker) and have slots in them for mounting a double rail. One of the issues I had with my old plates was that I didn’t do a very careful job drilling the holes to put the double rail system on them, which caused issues with getting everything aligned properly.
These plates also have the holes for the idler pulleys in a different place, which means that the belts will be located differently.
And they are painted black. 🙂
I also bought a box of Nyloc lock nuts to replace as many of the standard nuts as possible. I haven’t had any issues with nuts coming loose, but it’s never a bad idea to be careful.
Once that was done, I wanted to fasten together the two pieces of Makerslide for the Y axis. There are several ways that people are doing this, but I came up with my own.
I discovered that if you grind a bevel on two sides of a standard 5mm hex nut it will fit into the slot in the Makerslide – thus you can make your own captive nuts that are stronger than the ones supplied with the ShapeOko kit. So I made a bunch.
I believe that the 10mm long socket head cap screws that came with the ShapeOko were long enough to go through the Makerslide and not bottom out on the other side, but I’m not positive that was the length that I ended up using. In any case I put bolts and nuts on both pieces of Makerslide.And then slid them together.
It wasn’t quite as easy as it sounds, as the nuts tended to cock and bind up, but eventually I prevailed and got them together.
Leaving the bolts loose, I mounted the two pieces of Makerslide to the motor plates so that the ends would be flush. Then I clamped a pair of 1-2-3 blocks on top, and a pair of parallels on the bottom over the joint to line everything up and snugged up all the bolts.
Next I played around with the Z axis. The new motor mount plates are designed to have the Z axis Makerslide bolted to them and then just the router mount plate moves up and down. This should make for a stiffer Z axis.
Unfortunately I determined that this design was not going to work out very well for me. In order to have the Z axis reach down to the table I would need to hang the Makerslide way down under the motor mount plate. This means that it would run into the work piece and limit the Z travel.
The router that I have (a Rigid trim router) does not stick down below the router mount plate as far as a Dremel tool or the DeWalt that many people use, so this mount style is not going to work for me. Also I would have to make new router mounts as the ones I have now would not bolt to the plate.
So I had to go back to the old style mount. All the holes on the old Z axis plate lined up properly but one, so I had to drill a hole in it to match the new mount plate. I bolted them together and just ran the drill though the existing hole.
I ended up with pretty much the same Z axis I had when I started. But I did put new spacers in-between the motor mount plate and the Z axis plate (one 13mm and one 40mm spacer stacked to make the required 53mm.) So that should work out a little better.
I’m not 100% happy with the Z axis. There is still a bunch of flex, but I believe a lot of it comes from the plastic router mounts. I’m going to try and design up something different and I have a friend with a real CNC machine that is willing to make some parts for me. 🙂
After the Z axis was as sorted as it was going to get, I started to address the X rail height and alignment. I knew they were close, but they were not as close as I wanted them.
To start off with, the end plates were bolted to the waste board with lag bolts that were loosening with the changes in the weather. So those had to go. I found some long carriage bolts, drilled the mounting holes all the way through the boards, and bolted it down tight.
Once that was taken care of I needed a way to set the rails to the same height. I tried three different methods before I found one that made the most sense.
First I tried stacking up 1-2-3 blocks, gauge blocks and feeler gauges to the correct height for the bottom of the rail, but that didn’t get me as close as I wanted. It was difficult to set the rail height and keep all the blocks stacked.
Next I tried using my test indicator on my magnetic base as a height gauge, but it was too touchy and didn’t hold zero very well. But I got a little smarter and decided that instead of loosening the rail bolts and shifting the rails around I would cut up a pop can and put shims under the end plates. This part worked great.
Then I remembered that I own a 0-6″ depth micrometer. Duh. This was the perfect answer. I could measure from the top of the Makerslide to the table on all four corners and then shim until they were all the same. Easy-peasy.
So after the X rails were done I moved onto the double Y rail. This was a little harder, since I had to loosen the bolts and shift the rails around, and I had to make it level from front to back. But I ended up leveling one end and tightening the bolts, then I moved to the other end and set the height to match. The other end was level within a few thousands, so I just twisted it a little as I tightened the bolts up.
I checked the Z axis Makerslide to see if it was perpendicular to the table, and it was not. So I had to add some shims under the upper V wheel washers. I’m not sure why it needed shimming, but there it is. I used some punches to make shim washers out of the pop can.
Then I put the router into mounts, chucked up a straight piece of aluminum rod and discovered that it was not vertical at all in either direction. 🙁
I determined that I could adjust the front to back alignment by tightening and loosening the upper router mount clamp screw. I adjusted the left to right alignment by just kind of twisting the router. New router mounts have just moved up the list. 🙂
I was able to reuse the belt tensioners that I made for the X axis belts by moving them to the lower rail bolts, but I needed to make new ones for the Y axis belts.Rewiring was pretty easy, since all I really had to do was hook it all back up again.
I’ll have to run the Circle Diamond Square test again to see if all this work aligning everything made any difference at all.