Im new, am a 3D designer. Need a New cnc machine and need advice and guidance

[FlyHighRC]

Hi

i dont think i would bother with any of those, like the others sya, you could build your own for that, a little more money, you could build one 10* better. There are already some good designs on here and some already done in sketchup for the size your looking for. I will try find the ones i was looking at in sketchup, they was compleate, I would imagine all them have rigidity and accuracy problems.... You may get away with cutting a wing profile in foam with them, but i think, ( am also into RC ), you might struggle with smaller componants on them. especialy hard small parts ( alu car frame, helli bits, cam holders ). Do You FPV ?

Well CNC 1 has been on youtube and seems to go through aluminium fairly easily..6mm 6061 alloy and seems to do it in very little passes. If i wanted to build my own are there any build videos of a known machine where the parts are easy to findbuy and assemble? Id imagine getting the thing tuned would be a bi*ch.

Yeah I am into FPV. I Design Quadcopters mostly. I do love flying FPV and also do allot of survey work

[JAZZCNC]

Well CNC 1 has been on youtube and seems to go through aluminium fairly easily..6mm 6061 alloy and seems to do it in very little passes. If i wanted to build my own are there any build videos of a known machine where the parts are easy to findbuy and assemble? Id imagine getting the thing tuned would be a bi*ch.

Yeah I am into FPV. I Design Quadcopters mostly. I do love flying FPV and also do allot of survey work

Smoke and Mirrors.!! . . Yes they show it cutting aluminium but what they don't show or tell you is how much it takes out the machine.!
Cutting aluminium correctly needs a much stronger spec machine than any of these. Most machines will scratch Aluminiun away but to cut it correctly and accurately requires rigidity and NONE of these have enough to cut aluminium to any decent standard and survive. They will even struggle on cutting hardwoods at deep depths and decent feed rates.

My advice as usual is to save up a little and build your own or save up a lot and by something much better. The reality is that there isn't anything available to buy off the shelf much under 2.5K that is worth bothering with. The 6040 and these cheap Kits etc are just hassle and false economy, they under perform, break down wear out very quickly if pushed hard, even when not pushed hard they can be fickle things.!

The other thing you need to be aware of is the feed and speeds, Soft materials require higher feed rates and these cheap machines with poor under spec'd components and electronics often can't reach the correct feed rates to give good finish and tool life. If they do manage to reach them then they are often performing at Max capabilitys which puts them under excess stress, at best this leads to inaccuracy and missed steps but worse than that it shortens there life span very quickly.

[FlyHighRC]

Following my previous comment is it possible to build a machine? for my budget range and achieve good quality?

[JAZZCNC]

Following my previous comment is it possible to build a machine? for my budget range and achieve good quality?

Yes but don't be under any illusions that it's easy. To pull this off you will need to be well equiped and have the correct skills to use the tools.
With £1200-1500 budget you will have NO room for error or mistakes buying the wrong components.
Building with steel will cut the costs down but requires it's done correctly to achive accuracy, to be honest at this budget it's about your only option to achive accuracy/strength and still leave enough funds to buy the important stuff that makes for a good machine. These being Profiled linear rails, ballscrews and very important is decent quality electronics.

George runs thru the price of main components but what he doesn't mention is that there's a considerable amount of money that gets eaten up from things folks don't see or account for when planning.? Nut & bolts, Wire, Switches, connectors, cable chain and the list goes on. These can really eat money up fast if not careful.
One thing that often happens with people working on tight Budget is that they cut corners in the wrong places.? Often it's the electronics they turn on because they see this taking a big part of the budget.! This is the worse thing they can do and it's in this area where spending money on the correct components can pay dividends in how the machine performs. Get it wrong and take the cheap skate route and you WILL REGRET.
Next area to get the chop is Linear rails.? They often buy unsupported round rail because it's cheap, which it is, but it's also bendy and CRAP. Other option is to use supported round rail which is better but still not the best and comes with problems of it's own, Like constantly needing adjustment and poor accuracey.

Another area skimped on is the Z axis and material thickness.? The Z axis is THE single most important area of the machine and cutting corners here is BIG mistake as it holds the cutting tool and if this flexs or bends then doesn't matter how well rest of machine is built you'll get poor results.

Best advise is BUY NOTHING YET look around the forum at other builds to judge whats required and if you think you have the skills etc needed. If so then pick or design the kind of machine you require and start a build thread and ask advise. STILL DONT BUY ANYTHING until you have the green light and understand FULLY what and why your buying these componets. Again ASK advise on where to buy as often we will know where they can be bought cheaper.

With a Small Budget you have no room for error and in the blink of an eye with a few wrong clicks you could easily spend all your budget and still be some way off a fully working machine that will still under perform if you haven't done your home work.!!

Good luck and ASK questions before Buying.!!

[Robin Hewitt]

Most machines will scratch Aluminiun away but to cut it correctly and accurately requires rigidity and NONE of these have enough to cut aluminium to any decent standard and survive.

I must be misreading this, I thought that Jazz and me would see eye to eye about routing aluminium, I did go to Specsavers so it can't be that.

Did I see that the proposed mill only requires 10mm in the Z axis? Was that a typo? People usually allow 6-12 inches on the Z axis just in case they need it in the future thus destroying the machine for what they actually do. I think 2" or 3" in the Z is optimal if you want 10mm.

If you are going to rout aluminium I further suggest you copy the milling machine. On a milling machine the long bed is only supported in the middle because that is where the cutting happens. No point supporting it where the cutting doesn't happen, let it overhang, no problems.

To make your router strong, bolt Hiwin carriage blocks upside down to something solid such as a concrete joist.

Next bolt your gantry to the same joist so the table can slide through underneath it.

Why not make the gantry out of a second concrete joist? You don't have to move it so go wild on the dead weight.

If you don't like this idea, the usual excuse for not going down this route is, "It takes up twice as much space in the X axis and I haven't got room".

If you want to cut aluminium, design in a flood coolant return from the start, anything else is a ghastly fudge.

[JAZZCNC]

I must be misreading this, I thought that Jazz and me would see eye to eye about routing aluminium, I did go to Specsavers so it can't be that.

No Robin we don't agree at all. I'm referring to the machines suggested lower down but your still banging on about that old chest nut that Routers can't cut aluminium properly.! . .Which is frankly stupid because there are many of us on here that do it quite nicely thank you.!

Agreed on the concrete machine thou, correct Concrete and epoxy can make a very solid machine.!!

[Robin Hewitt]

No Robin we don't agree at all.

That's a relief. I was just doing the forms to renew my gun/explosive certificates, can't afford anything that might cast doubt on my sanity.

[Clive S]

This must be the longest thread on here with nothing achieved ..Clive

[FlyHighRC]

I resent that :P I ahve learnt allot from this bunch, also I reply quick when I want to learn quick..seems most post on this forum are responses 2 weeks apart...