X axis Ballscrew

In this session, I added the X-axis ballscrew. It is identical to the one on the Y axis, so that should make sourcing easier and cheaper. I'm using an off-the-shelf ballscrew mounting bracket that attaches to the X plate with some bolts. It attaches to the ballnut and keeps everything rigid. I needed to make the X plate a little thinner, as well as make the extensions for rail mounting larger, so the plate can fit over the X motor mount.

Z axis + X motor + Fixture plate

In this session I added most of the Z axis to the mill. This rides on two more HGR20 rails, and the carriage is a 1/2 inch piece of milled aluminum. It has four tapped holes to hold the 65mm spindle clamp, a common off the shelf part. This part is fairly simple, but I will need to modify it a bit to allow the ballscrew and the ballscrew mount to fit between the rails.

I also added the X motor in this session. Its another nema23 on the same ball screw mount. Its attached to the steel tube with 6 m6 tapped holes. I also added the ballnut mount on the X plate. I had to thin down the plate a bit, but kept the mounting for the carriages where they were. This lets me keep the same general dimensions while allowing space for the ballnut mount and the ballscrew.

Finally, I added the holes on the fixture plate. I may end up milling these on the mill itself so its square, but im not entirely sure if that is the best way to do it. I need to research what others do. Its essentially 19mm grid of m8 holes that I can put fixtures in to hold parts down to the table. It will be painful to tap 272 holes so I may end up milling it in place.

X Axis Plate

In this session, I added the X-axis plate. It is basically a 25mm thick piece of aluminum with some counterbore holes for the carriage mounting, and m5 tapped holes spaced 60mm apart for the rail mounting. This should make it very rigid and be able to hold the spindle and resist the cutting forces. The X axis itself is a huge piece of 6x2 RHS, with holes tapped every 60mm for rail mounting. I still need to add ballscrews and motors to the X and Z axes, as well as the Z mounting plate, which will hold the spindle. I may need to space the rails out from the tubes to be able to put the ballscrew under the plates.

Added Y Ballscrew

In this session, I added the Y ballscrew and motor mount. It is an HM12-57 motor mount, perfect for a 16mm ballscrew and a NEMA23 motor. I have it mounted with six M6 bolts, which are tapped directly into the steel tubes on the back of the mill. The ballscrew is 500mm long, which should give me around 300mm of Y travel. Next, I need to add the other end of the ballscrew mount, which should be pretty easy, as it is just an off-the-shelf mounting bracket. I also need to add a way to mount the ballnut to the plate, but this should also be fairly easy, just an aluminum block.

Base Reinforcement + X Axis + Bed

I did a LOT of work today. I started by beefing up the frame a bit. This was to: 1) make it more rigid, 2) make it use fewer different types of steel, and 3) make it easier to assemble. Overall, this was a good change, but it may make it slightly more expensive. Now it's almost entirely made out of 2x3 RHS, with a couple of different pieces here and there for rail mounting.

I also added the X-axis during this session. This is a big 5x2 tube with two HGR20 rails on it. Eventually, it will have a 16mm ballscrew running down the center of it. I may need to use some spacers to give the ballscrew room to move.

Lastly, I added a template for the work plate. I'm not super happy with this yet; it doesn't seem very solid, and I should probably add some reinforcement. Right now, it's just so I can see the travel I can achieve on this setup.

Lets Start Again

I realized that I would not be able to fit the thick steel and aluminum extrusion in the budget. I have switched to using steel tubing as it's available locally for cheap (<$2/kg) so I have decided to use this. It will also make it more rigid, as the tubing itself makes it a lot more rigid. I could also fill the tubes with epoxy granite which would make it even more rigid. My first design was hastily thrown together and not really thought through well. Just the steel plate would cost more than 300 dollars. That just is not reasonable. This steel frame was inspired by the PrintNC project, but this is a bedslinger mill and not a gantry mill. I think it should work out fairly well. This looks like a big step back but for the actual mill it should be a big improvement.

Added Verticals

In this session, I added the verticals and the X rail mounting extrusions. I once again used 10mm steel plate, with two 380mm 4040 extrusions to connect them and mount the rails. They are mounted with a ton of m5 bolts, which I may end up replacing with some hex bolts, which should be easier to torque down with an impact driver.

I also added the Y-axis rails. They are currently HGR20, but I will probably change it to HGR15 for space and cost reduction. It should be very rigid either way. They will have two carriages each, as well.

Designed the Base Frame

In this session, I designed the base frame for the mill. I'm currently using 4040 extrusions and 10mm thick steel plates. The steel is held together by many, many M5 bolts, which should help the rigidity. I think that this should be rigid enough for my purposes, but I'm not super comfortable with the aluminum extrusion. Ideally, I would be using a steel box section, but this would get expensive very quickly, and it's hard to find small lengths of box section locally. I might end up changing it, but we will see.

The frame will be holding the Y linear rails (HGR15) and also the NEMA23 for running the Y-axis ballscrew. I want to keep this machine rigid and precise, and having these components, as well as a very sturdy frame, should set me up well. I want to be able to cut aluminum using this mill, and maybe some other more difficult-to-machine metals. So far, I am pretty happy with how it is turning out.