3 Axis CNC router

[JoeHarris]

Waste of money buying the pumps for something like this, couple of plastic measuring jugs from the supermarket will do the job, west systems is a 5 to 1 ratio & you would need a slow hardener. West systems is a good product but I would imagine a cheaper resin would do just as good a job for this sort of thing. Not sure about the process of filling a machine frame but generally speaking adding something like 403 or 404 fillers will aid. You can find a list of fillers & uses here. I generally use the 403 but that's more specific to work I do & not filling a machine frame.

Is it really necessary to start filling your frame with resin?! How much of a difference in finish are we talking for the extra expense and hassle?! My gantry will be ali extrusion in the L configuration btw... I don't want a terrible finish on my work at the end of all this but at the same time I'm not going to be machining parts for Breitling!

[D.C.]

I would have thought polyester resin would be fine since it's only filling the frame.

Polyester isn't suitable because it shrinks too much apparently, I would refer you to the exact part of the epic thread on cnczone where that is discussed but I'm not reading that bloody thing again!

Is it really necessary to start filling your frame with resin?!

The whole point of being a cheapskate diy chappie is spending the least amount of money possible for the quality you want, if your machine is serving you great with steel box then it ain't broke so don't try and fix it. If you want better stiffness and vibration dampening to give better quality then it's an option open to you.

[Swarfing]

If you want to make sure all the voids are filled then try using an orbital sander against the box to work like a vibro rod. Just put a bit at a time in and vibrate the hell out of it.

[JAZZCNC]

I wouldn't bother with resin it's messy and expensive.!!. . . . . . If you need to dampen Just use kiln dried sand It's cheap and nothing works better at damping resonance.
Build in a drain hole has well a fill hole and you can easily remove when need to move machine around.

[Jonathan]

Polyester isn't suitable because it shrinks too much apparently, I would refer you to the exact part of the epic thread on cnczone where that is discussed but I'm not reading that bloody thing again!

Surely that's because they're discussing using it for making bearing surfaces, where clearly the dimensional tolerances are critical. Does it really matter here if it shrinks a bit...

[D.C.]

Surely that's because they're discussing using it for making bearing surfaces, where clearly the dimensional tolerances are critical. Does it really matter here if it shrinks a bit...

I'm not sure tbh, if you have a solid, shrunken lump inside of a steel box surely most of the vibration will just stay in the steel and not pass into the EG, the steel beam would also deform like normal steel until it made cotact with the EG beam?
This is why someone really needs to part with some cash and do some directly comparable real world tests...

[JoeHarris]

Revised 80x80x3 SHS frame - brings the cost down quite a bit. 6mm plate and/or welded connections...

[CraftyGeek]

Just been going through the whole of your thread, its given me some good info for my design/build....where are you at with it now?