MikeM's CNC Build

[mikem]

To help get the new CNC sub-forum going, I am posting the progress report I posted on another forum.  I am including the original post dates as a frame of reference on these.

Original Post date: 9/14/2017

So as I have alluded to in some other posts, I am in the process of build my own CNC. I started the process earlier in the year, and have spent much time planning and procure (as the budget allowed) the various components for the machine. I worked with a friend who designed and built his own CNC a number of years ago to design my machine.

The build got started in July when I assembled the frame for the gantry. From there I built the stand. So far the most time spent was making the bed. Which is a torsion box design made out of MDF. I went this route as the torsion box design is very strong, flat and stable, with the added benefit of the MDF being heavy, which makes a solid foundation for the machine, and to help dampen vibration.

Last night I reached the milestone where I successfully attached the gantry to the bed, and was able to (With ease!) move it back and forth. I posted a couple pics, and here is a link to a quick video of me moving it: https://www.instagram.com/p/BZAPFd_F4bv/

Materials used so far:
Plywood for the stand
MDF for the bed
8020 (30 series) extruded metal (size 6060 for the side rails, and the uprights for the gantry, 6030 for the rails of the gantry)
Linear Bearing Rails are SBR20
Lead screws are C7 Ballscrews

[mikem]

Original Post Date: 10/2/2017

I have made a little more progress on my build. I completed installing the lead screw for the bed axis. I made and glued brackets to the bottom of the bed to hold the mounting blocks for the screw. I drilled a hole in the center of the 8020 bar on the bottom of the gantry so that the screw can pass through it. I also fabricated a nut adapter out of aluminum plate so I could get the screw nut attached securely to the 8020. There were a few first for me on this, as I have never worked with a blank of any metal to make it into something useful. I have also never tapped screw threads either. I was able to get everything assembled, and tested it by attaching a battery powered drill to the screw, and was able to move the gantry back and forth with it.

[mikem]

Original Post Date: 10/13/2017

A quick progress update. I worked on attaching the lead screw for the X Axis on the gantry. The 8020 bar that holds the screw is set back on the gantry for two reasons. First, if it was lined up to the other two bars, I wasn't able to get the anchor fasteners tightened, and two, it does add it the overall rigidity of the gantry. So I ended up fabricating L brackets to extend up high enough so that the screw will be centered to the stepper, once it is mounted, but also so that the nut was below the level of the bearing guides. It took some tweaking to get it where I wanted it.

My next step is to start making a prototype of the Z Axis, out of MDF. This will help me work out any issues that I wasn't able to identify in my drawings, as well as allow me to order the exact amount of aluminum plate I will need.

[mikem]

Original post date: 10/23/2017

Made some more progress on the CNC this weekend. First the longer rails for the gantry I ordered arrived. I decided to get the longer rails after taking some measurements of the bed, gantry, and lead screw, and found that I would definitely benefit from a little large capacity. (About 2-3 inches mores) After getting those installed, I worked on making prototypes of the parts I will be making out of aluminum plate with MDF. Next steps, I need to source the ½” aluminum plate and fabricate the actual parts. Also, I need to finish the stand the CNC is on. I need to put the bottom shelf in place, and build a rack for the PC and control panel.

[mikem]

Original Post Date: 10/30/2017

A quick update on my build, as I am still waiting on my aluminum order to come in. This weekend I milled and cleaned up the 2x4s I used to make a level surface for the torsion box bed, and used that to make a shelf that the control box will set on once it is build. I started getting ready to draw up the design for the enclosure, but after some discussions with a friend, decided I was better off waiting on that phase until I have all the electronics that will go in it in hand. I have all the aluminum for the machine ordered, so I can provide a more complete materials list that have gone into this machine, not including the electronic components. Once I get those ordered, I will provide a complete list of those.

1 sheet of 3/4" MDF - Torsion box bed
2 rails 8020 30-Series 6060 39.5" for side rails. Full machine is supported on these rails
2 rails 8020 30-Series 6060 25" for gantry upright
4 rails 8020 30-Series 3060 27" for gantry rails
2 lengths of 12"X2.5"x2.5"x3/16" angle aluminum
4 pieces of 6061 Aluminum plate 14"x3"x3/8" for various adapters and brackets
2 pieces of 6061 Aluminum plate 8"x4"x1/4" for router hanger gussets
1 piece of 6061 Aluminum plate 36"x8"x1/2" for Z axis and router hanger
1 Sheet of 3/4" Plywood for stand
4 2x4s for level surface for bed construction, then for shelf
2 SBR20-L300mm Linear rail guide
2 SBR20-L700mm Linear rail guide
2 SBR20-L1000mm Linear rail guide
1 SFU/RM 1605- L350mm-C7 ballscrew with end machined
1 SFU/RM 1605- L650mm-C7 ballscrew with end machined
1 SFU/RM 1605- L1050mm-C7 ballscrew with end machined
12 SBR20UU Linear blocks
3 BK & BF 12 support for ballscrew
3 6.35x10mm Flexible Couplings
1/4 Sheet if MDF for scratch surface
T-Track
Casters
1/4 sheet of Plywood for retractable casters (not made yet)

[mikem]

Original Post Date: 11/20/2017

Since my last update, I got all my aluminum plate in that I will need to finish out the X axis and to build the Z axis. The biggest piece I ordered was 8”x 36”x ½”. That piece was heavy. I got it cut down to the pieces I needed a couple weeks ago, and last weekend started working on the plate that will move along the X axis. This is where I ran into some issues. If you recall, I made an MDF prototype of this piece. It turns out the MDF was not flat, and threw off my measurements for the real piece. So the first attempt at drilling holes ended in failure. I couldn’t get all the screws in, and the plate was way out of square. Attempt #2, I didn’t use the prototype for drilling as I did on the first one. However, I discovered that when I cut that plate, I must have had some blade deflection as the ends were out of square. Unfortunately, I did not discover this after I drilled the holes the second time. After widening the holes, I did get all the screws in, but the plate was out of square, and did not move well.

Attempt #3…. This weekend, I FINALLY got it right. After shortening the piece by an inch to get it squared up, and to make an offset to have room to drill more holes. I did the layout completely fresh directly on the work piece, double and triple checking everything for square, as well as checking alignment on the machine. I did my drilling in phases so that I could make sure I was staying in alignment. The result was all the screw holes were 100% right on! This resulted in a very square alignment of the plate, and very smooth travel. Once all that was verified, I counter-bored all the screw holes so that the heads were below the level of the plate, leaving room for the rails for the Z Axis.

Next step is to work on the nut adapter so that I can get the plate attached to the lead screw, and then start working on the Z Axis.

Link to video of me moving the X Axis: https://www.instagram.com/p/BbshV-rF...ken-by=mamader

[mikem]

Original Post Date: 11/28/2017

I was able to take advantage of the long weekend, and got more work done on the CNC. I fabricated a nut adapter so that I could attach the X Axis plate to its lead screw. This was a bit of fussy work so I could get a perfect fit, requiring me to take a bunch of pieces apart every time I tested the fit. I was finally able to get it. After I got that fitted, I spent some time getting everything buttoned up and solid. If you notice the adapter I made extends back a bit. This is so I have something that will make contact with the stops I put in. Once I get the limit switches, these will mount to the stops. The last pic shows the CNC in its current state, ready for me to start working on building out the Z Axis.

After I got to that stopping point, I did a MASSIVE shop cleaning, as it was an absolute DISASTER. 

Link to the X Plate moving under drill power: https://www.instagram.com/p/Bb0dawol...ken-by=mamader

[mikem]

I am now current with the posts.   I have been working on the Z Axis, and will get an update and pics posted once I have made sufficient progress.  I am moving a little slower on it right now, as my only heat in the shop is a kerosene heater.  This unfortunately means I don't get as much time to work out in the shop since I am limited to weekends only now.  (Takes too long to heat up to make the shop usable during the week)

[difalkner]

That's a really nice build, Mike!  Looking forward to seeing it added to in the coming weeks.

David

[mikem]

Thank you David! 

[Mick S]

Really impressive, Mike! Can't wait to see it fired up!

[mikem]

Thank you Mick!  I am looking forward to seeing it going as well!  

I saw you have a build going as well!  Should be a nice machine!

[Mick S]

Any updates/progress on your build., Mike?

[mikem]

Hey Mick, alas, I haven't gotten much shop time since the end of November.  My shop is an unheated garage (except for a kero-heater that the outside temp needs to be over 30 to be usable).  Between the busy holidays and the VERY cold temperatures we have had, I haven't been able to work on it.  Hopefully will get a chance to work on it again soon! 

[mikem]

So I managed to finally get some time out in the shop. I worked on getting the Z-Axis rails mounting holes done. This included drilling out and tapping the screw holes. Once I got the rails mounted, I wanted to see how close I got it to the original prototype. If you recall, I had a lot of problems with getting the X-Axis plate mounted properly, so I wasn't using the prototype as a guide, but rather went back to measurements. I was pleasantly surprised that the prototype plate fit! This will help a great deal with making that part. Hopefully I will get some more shop time soon!