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

[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
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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?

[george uk]

just about, but if you up your budjet by a few 100 to say 1500, then yes , you can build a quality machine.

300-500 for motors, controllers BOBs and electricals excluding spindle and controller ( 200-300+)

about the same for linear components ( bearings,slides, screws )

there are about minimum, excluding the frame, if you look about BUT TAKE ADVISE BEFORE YOU BUY ELECTRONICS. BUILD THE FRAME FIRST.

If you know anyone that can weild, you can build a good frame cheaply enough out of steel, just use ally were required

[FlyHighRC]

IM loosly thinking about designing my own frame and posting the renders for approval by you guys, Is that a good idea or should i find a proven build? If so...know any? :D

[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.!!

[dazza]

So what would I need?
6)Linear mechanisms? Any recommendations for for round bar or square rails?


Where can I buy extrusion? And any dimensions online? Would really help with putting this all into Solidworks :)

Thanks again guys

regarding screws and rail most of us use chia in the link he does the rail and ball screws,there are others but he was the only one ive come across that will machine the screws to length as well as end machineing to your specs to cater for pulleys should you use them.
6SE Linear Bearing Rails 3 ballscrews Balls Screws 1605 BK12 BF12 3 Couplings | eBay
profile rail would be nice but even used you might be pushing it on your budget.

extrusion.. just one place i and others have used a bit http://www.kjnltd.co.uk/

[FlyHighRC]

Is it possible to make a good SOLID machine using extrusion? I have read mixed points of view about this stuff...Some say its really ideal for upgrading a machine in the future and provides a good solid frame while other say that its rigidity could be called into question.

I am able to get easy access to a welding machine and welder(friend) but would rather not go down that route( Cutting steel,jiging, powdercoating etc) If i can make a CNC from extrusion..that would be ideal. Though I wouldnt mind making the gantry out of thick steel screwed into the linear blocks. That wouldnt be a problem.

[JAZZCNC]

Is it possible to make a good SOLID machine using extrusion? I have read mixed points of view about this stuff...Some say its really ideal for upgrading a machine in the future and provides a good solid frame while other say that its rigidity could be called into question.

Yes it is possible but it needs to be done correctly and using heavy duty profile which is very expensive when you factor in the correct fixtures etc required to make it work. Flimsy 40x40 won't cut it and You certainly won't get much machine for £1500 using profile for the frame.
Steel in comparison is very cheap and stronger but requires more effort and skill on the builders part. If your on a budget then forget profile you just won't do it and have machine that's strong enough.

[FlyHighRC]

Hey guys, Spent most of the day researching CNC designs. I am now pretty sure I want to design my own. I Feel i am able to build this machine...I have a decent workshop filled with tool and my grandfather has a model engineering workshop with manual mills which could come in pretty handy.

The only issue im having is pairing up the hole sizes in the rails to be able to fit the extrusion. This is becoming pretty frsutrating as I cant seem to find extrusion,rails(supported round and linear) that want to fit eachother easily.

Could you guys point me in the right direction of parts that are almost plug 'n' play please.

I also found this CNC Kit it seems pretty good to me but im not the expert here haha. If you could help Id really appreciate it

[FlyHighRC]

No extrusion then aye...bummer, look much simpler haha