| Gallery, Projects and General > Project Logs |
| The CNC experiment build. |
| << < (10/21) > >> |
| RotarySMP:
Your x bearing blocks look far too close together. I just cast a polymer concrete test bar. Added 5g of carbon black from an old printer toner cartridge. Made 1.2kg of E/G nice and black. 10% epoxy was stiff but still sagged why a little vibration. I just tapped the mould on the floor for a few minutes. With a proper vibrator 8% epoxy should be fine. I mixed in the aggregate from fine to coarse. The first and last were hardest to mix. Mark |
| NeoTech:
Ah well, i cant fit them any other way, its wide heavy load bearing blocks. on a 30mm rail. So it starts to interferce with other stuff when moving around sadly. So its a bit of a compromise. So the question comes to then i guess, can i conjour up a vibrator for a 300kg casting.. i have a 0.75kW electric motor that maybe could do the trick.. 1450rpm, a slightly offseted weight out of some aluminium roundstock maybe works?! Got any picks of the brick? =) |
| philf:
--- Quote from: RotarySMP on February 22, 2015, 03:59:12 PM ---Your x bearing blocks look far too close together. Mark --- End quote --- Neotech, I noticed that too. When working at the ends of the table it's cantilevered. I think I would have the rails attached to the table and the blocks attached to the saddle. To do this you'd probably have to fix the screw to the table and the nut to the saddle. This way the spindle is always centred between the bearing blocks. Just my 2p worth. Cheers. Phil. |
| NeoTech:
Have actually considered that approach.. should prob. take me the time to cad that out as well. Just redone the table like 10 times already so. =) Would also allow for a smaller saddle with no overhang im guessing. One of the issues i have is getting thick plate cut and drilled or even get hold of it. Its a bit why i approached the table like that. But i should reconsider that - and see what a slab of castiron cost actually. |
| RotarySMP:
Normally, on the rigid industrial CNC's they put the blocks on the ends of the table and the rails on a fully supporting saddle. That gives the most rigid configuration. The way you have at now, you have the disadvantage of a full length saddle, with the low rigidity of bridgeport saddle. Mark |
| Navigation |
| Message Index |
| Next page |
| Previous page |