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Re: John's Alu Profile build
Here's a picture of the main machine as it is today.
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Re: John's Alu Profile build
Here's a couple of shots of the spindle and Z axis details.
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Re: John's Alu Profile build
The Z axis came with three optical sensors inside, I kept one in there as upper homing limit switch and reused the other two as home/limits for the Y axis, one each side. For mounting I machined a carrier from Delrin/Acetal. I'll probably replace this with aluminium at some point soon.
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The plates which mount between the Y axis bearing blocks and the gantry were modified to fit a piece of aluminium L profile, this moves into the optical switch when homing.
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For mounting the Gantry to the ballscrews on the Y, I had a local company weld me up some brackets to my design.
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They made a bit of a balls of it to be honest, It's not square and I had to rework it by hand a lot. I can't weld so I didn't have much option, I really should learn to. Since I'm replacing these chinese ball-screws with ground screws from TBI I'm not going to sweat it just yet. Once the parts are here I can redesign this part and the motor coupling for each.
I'm using LinuxCNC 2.8 for this with kins, if anyone wants me to upload my .ini and .hal files let me know. It's working well so far.
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Re: John's Alu Profile build
So, as I said the spindle is from China, but seems to be much better quality than the regular ones, certainly run out and machining quality is amazing. Running at full pelt it is really smooth.
Here's the company if anyone is interested (no affiliation with them at all btw): http://www.jian-ken.com
The VFD is model RS510 from RS Electronics (no affiliation with these either): I'm really happy with the quality of this too. It's actually rated for 2.2Kw but I thought some overhead would be a good idea. Definitely one to add to the list for the other Chinese spindles too.
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Part of the reason it's taken me so long, apart from sourcing all the parts here and there, is the fact I had to build myself a little workshop to house it in.
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I still have a bit to do to finish this place, insulate it in between the stud walls and plywood the internal walls, but it's dry and solid.
At the right hand side outside you can see the six inch blocks. I don't know if these exist in the UK or not but my idea was to build a wall with these on the flat and bolt the entire CNC to it with the Y rails running parallel to the floor. If anyone has an experience I'd appreciate some advice.
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I'm really not sure how I would level a wall to the degree necessary to accurately fit this too, but maybe I'm overthinking it.
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Re: John's Alu Profile build
As a test, I knocked up a pencil holder out of some delrin and some drill rod, with a spring for applying pressure and for accounting from deviations in the surface. It worked great, but the chinese ball-screws really aren't great (noise, vibrations etc.)
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I actually sourced angular contact bearings for the BK12(?) blocks, so I might now have to sell those too.
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Here's a snap of the internals of the control box, the main cabinet was sourced from RS electronics and I fitted the rest after bench testing. I probably could have used a smaller case but I have plenty of space so I don't mind the extra space from a cooling perspective.
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I went with GX 16 type pins for termination of the wiring both on the motor/sensor side and the case/enclosure side. The wiring is done so that the case side takes the Sheild of each wire to earth.
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I think that's all I have for now guys/gals.
Re: John's Alu Profile build
A couple of questions I have, then, if you don't mind:
+ Playing with the machine as it stands, there's a lot of resonance from the hollow sections of the profile, for the Y profiles I intend to either fill with sand or maybe epoxy/granite. With one end almost closed at the front and the significant vibrations from the less than stellar 1605 ball screws these are resonating like an instrument at the moment. I'm sure this will hurt surface finish as I can clearly feel the transmission through to the spindle by hand, but I expect a sand fill will help since these parts won't need to move.
+ With regards the Gantry, I'd imagine filling that with epoxy/granite will be much too heavy for my motor/screw combo (480oz/in plus double nut 2005 ground ball-screws). Has anyone any experience with filling the voids of profile with expanding foam to dampen vibrations/resonances? I suppose I could test a piece but I don't have any spare material to hand. I wonder if something like silicone fill could work if it could be done cheaply enough.
+ Also would be keen to hear any input from the idea of bolting this entire CNC to a concrete wall, specifically how I might line everything up in practice. I like the idea of gravity pulling away chips and using less floor space but could just go for the traditional setup.
Re: John's Alu Profile build
Hi John
Regarding vertical mounting you will have to build yourself a substantial base, if you make another post asking for ideas for designing a vertical assembly machine Dean(JAZZCNC) might give you some advice regarding this, he has a video of one of his larger builds but i couldn't find it.
Regards
Mike