[Fairshotguy]

Sorry about the double post but after looking around the site this seemed like the logical place to post this.


"Hey guys, this is my first post and I really hope this is in the right spot. Over the past few weeks I've started to design my fist cnc machine, it will use a dremel and have a mobile gantry. After a little reading I see that the dremel is not the most rigid thing out there, so my thought was to make a new housing out of aluminum. I have one drawn up in autoCAD right now but i'm not sure if it is overkill or on, would this help at all or are the bearings going to allow play anyway? Any help will be greatly appreciated.

This was designed for a dremel 400 XPR"

[lucareds7]

if you want to make a dremel barbeque, you're on the right way!
jokes apart, your solution is very stiff and this will increase the finishing of surfaces, but it won't provide enough air circulation to avoid burning of rotor coils and brushes. Take in consideration that even the bearings are not he best, they tend to damage quickly if you apply relevant forces both axially or radially. My suggestion are two:
- buy a router milling unit from Milwaukee, Atlas Copco, AEG, Dewalt, Bosch... they cost about 100 - 150 $ with about 800 W of power, 10k to 30k rpm and spindle accomodating bits from 2 to 8 mm
- make a spindle by using a shaft mounted on two bearings, on one side mount the bit and on the other side mount a flexible coupling to be attached to an electric motor. The intermediate solution would be coupling Dremel with flexible shaft to your homemade spindle, but take care because as i wrote above Dremel is intended for small and quick works, not for milling continuosly for a day.

Luca

[Fairshotguy]

Thanks for the reply, I guess I forgot to mention that this is not my final design. The picture I posted is only about half done, there will be air vents at the rear and the impeller to draw air through the motor. So would something like this have any benefit to just buying a router like you said, note that the only reason I'm considering this is because I already have the dremel.

[lucareds7]

If you have some time to spend on it, a compressed air nozzle would be better than an electric fan because moreover the flux, you have the cooling of the air due to the adiabathic expansion. A wonderful system which employes this technology is the "Vortex tube", you could easily build one on a lathe
Good work!
Luca