is Epoxy levelling just for steel ?

[Hulksmash]

Hi guys,

Sorry to ask a question that probably sounds really stupid, I'm new to CNC.

Is Epoxy levelling still required for Aluminium box section or just for steel ?

I see people using aluminium profile - how do they level that ?

I am just costing up the start of the build and wondered if using aluminium would be better ? (taking into account epoxy - skill required and levelling time)

many thanks in advance

Mike

[pippin88]

Steel is cheap, easy to weld, stiffer (per weight) and heavier (per volume) than aluminium - that is to say steel is great for frames.

Aluminium is perfectly usable, but harder to weld, more expensive, etc. Epoxy does not stick well to aluminium without careful prep.

Aluminium profiles are usually "flat enough". That does not mean they are flat, but for a wood router, relatively less precision is required.

[routercnc]

My mk2 and mk3 used aluminium profile to bolt the rails to and I made plenty of good parts with it (including parts for the current mk4 under construction).

I did not flatten the surfaces or prep them and it made a very useable machine.

You can buy pre-machined aluminum profile which will make them very flat but you pay more for it.

[Hulksmash]

My mk2 and mk3 used aluminium profile to bolt the rails to and I made plenty of good parts with it (including parts for the current mk4 under construction).

I did not flatten the surfaces or prep them and it made a very useable machine.

You can buy pre-machined aluminum profile which will make them very flat but you pay more for it.


Would aluminium box section be the same as profile for how flat they can be ? I believe they are both formed the same way.

Many thanks

[A_Camera]

Would aluminium box section be the same as profile for how flat they can be ? I believe they are both formed the same way.

Many thanks

Aluminium box profile is not a good idea for this purpose. They twist and deform too easy and are not very flat unless special made with very thick walls. Especially once you start drilling holes in the box it will be noticeably worse. If you use aluminium profiles get 45x90 or better. My machine is built based on 45x90 but it is regarded as small, so it's OK for that. I mill aluminium, PCB as well as other, softer material, but my work area is 310 x 270 mm with a 150mm maximum Z. The total weight is about 90kg, excluding the PSU, electronics, wiring and the spindle. The foot print is 750 x 650mm, it is a stand alone type with fixed gantry beam, moving table.