El Beast - Initial design phase, comments and critique welcomed!

[Desertboy]

Back to the build!

So had a chance to make my rail alignment doohickeys:










My plan to cut them so that the critical height is on the same part of the ballscrew seems to have worked well:

13.499mm



13.500mm




Biggest variation i found was 13.497 to 13.503, so max variation of 0.006mm (0.00024 inches if you are that way inclined), so pretty happy with that.


I 3d printed a jig and made some drill bushings on the lathe, looks like a shocked robot:



After drilling, tapping and a quick de-burring I gave the 20mm bed plate a good clean and laid the machine down on it upside down. Wiped each piece and area with an alcohol wipe to try and minimise any dust or dirt before fastening the rail spacers into position against the bed plate as a reference.





Then finally gave the rails a good wipe with a vanguard anti-corrosion wipe (hopefully minimise any naughtiness between the steel rail and milled aluminium mounting surface) before mounting them against the rail guides.




Next up will be re-making the front plate after my motor mount height snafu, then I can crack on and get this lower frame finished off before moving on to the Z-axis next.

0.006mm!

Excellent work I guess you don't need to write in your ebay descriptions please allow 1-3mm for measurement errors lol.

[Zeeflyboy]

Cheers chaps.

Desert - I was more impressed when I wheeled the first one off and it was 13.500mm which is exactly what the model was supposed to be. Pure luck, my machine isn't that accurate lol. The variation is pretty impressive but that comes from cutting on the same part of the screw I'm sure.

[Zeeflyboy]

Always painful when you are going back over the same steps, even more so when you mess up too....

Re-made the face plate today with the re-positioned bearing mounts to account for the different height motor mounts. I also tweaked the design to give more adjustment around the bearing mounts to hopefully make aligning them with the screws easier.

Interior done:




Using my new 10mm roughing end mill with 10mm DoC, 1.4mm tool engagement, 2000mm/min and 14000 rpm I blasted through the exterior roughing, was just in the middle of congratulating myself on how much better I'm getting the hang of fusion's CAM abilities until the very last bit where it had decided to machine out one of the bolt holes that was occupied by a steel bolt - result was a new but now broken $30 10mm roughing end mill. FML....





Anyway, aside from a broken endmill at least it had finished the exterior before committing suicide... So I ran the finish paths and all was well, but then I went a goofed again and ran the wrong tool path - so it tried to do a chamfer with a 6mm flat end mill. Hit stop before it got too far but still an unfortunate mark on the front right side. Just a cosmetic issue thankfully, but still annoying.






Good news is that at least its done and the error with the motor mount height is fixed.... One day I'll be able to make a simple part without messing it up, I'm sure. That's the dream!

[Zeeflyboy]

Made one of the screw mounting plates:






Flipped for the rear side, it was previously held down at the near edge too but I removed the front clamp to run the chamfer.




Unfortunately it's way too tall to fit into the CNC for drilling the sides, so I 3D printed another jig and made some drill bushings on the Lathe:






Nice snug fit:




Drilled and tapped:




Assembled:






Fitting to the machine reminded me that I need to flip the nuts on the screws and also showed a small design tweak that's required to then give the nut clearance, other than that though the fit is spot on regarding heights and spacing.

[Desertboy]

Damn, that's some very nice work there.

[routercnc]

Sorry to hear about your troubles in post 170. Annoying when the part is big like that and expensive to replace.

Drill guide templates are very handy to make sure the holes are precisely where you want them. Got some more to do in my build later on.

When you flip the ball nuts have you got some metal tubing to roll them onto to keep the balls in place? If not I can measure the tube I use so you can turn something down.

Good work - keep it up

[Zeeflyboy]

Cheers desert.

Sorry to hear about your troubles in post 170. Annoying when the part is big like that and expensive to replace.

Yeah very annoying, but could have been worse I suppose...

When you flip the ball nuts have you got some metal tubing to roll them onto to keep the balls in place? If not I can measure the tube I use so you can turn something down.

They came with some plastic tubes actually, but thanks. Of course I tried to use the Z-axis 1604 ball screw's tube for the 1605 and the end result is that tonight I learned how to re-pack a ball nut lol. Thankfully I did it all in a sandwich bag so no balls were lost. Helps when you use the right tube

Other than that I made the required design tweaks and modified the plate... I wanted to give the cutout that clears the motor mount a little more clearance and I also made room for the flipped nut.

Aligned the plate using dowels to make sure it was square to the axis, then used a probe to determine zero... occurred to me that perhaps not many have seen the touch probing screen on mach4, quite convenient to use for most circumstances:






modifications made:




Fitted to the machine, for ballscrew alignment the plan is to assemble by the fixed position motor mount here:




Then drive it up to the top with the floating bearing mount screws loosened off, then re-tighten once up there... ensures the screw is lined up to the linear rail at both ends. So far seems to have worked as it's nice and smooth at both ends with no binding.




Now I just need to make the other side