I'll eventually go this route I reckon:Quote:
Originally Posted by JAZZCNC
https://www.aliexpress.com/item/4000543415213.html
48V power and driven by a UC400eth.
(well, if I can make any £ that is).
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I'll eventually go this route I reckon:Quote:
Originally Posted by JAZZCNC
https://www.aliexpress.com/item/4000543415213.html
48V power and driven by a UC400eth.
(well, if I can make any £ that is).
Thanks guys, okay slowly getting some clarity
Think im going to go for the planetcnc Mk3/ 9 axis controller with ethernet as I really want to run this from osx. Its first I've heard of reliability problems of usb - I didn't know it could be a problem. I guess if you have large job/ material and committing time to a part build the last thing you need is any corrupt data!
My design is quite similar similar to that of diycnc http://www.mycncuk.com/threads/11628...per-CNC-Router
however a fair bit smaller. I plan this to be a small desktop machine, same size as the EVO (why are there so few reviews or videos of that machine?) and come in under 50Kg ideally , 40kg is a push im sure.
I have access to a workshop and a welder friend however he's suggesting I go with T slot Ali to prototype, then weld a proper gantry from 25mm square steel section later
In terms of the main components, and given the size, I have a couple of questions
1) should I use hiwin 15mm rails for all guides, including X? Or is this overkill - maybe use round bar for the x axis?
2) what brand of ballscrew should I use? I read some reviews suggesting some brands have lots of backlash - are Chinese suppliers generally okay?
3) For the Lichuan drives linked above and for this size of machine are these going to need more than a 320W power supply? Im keen to keep this low profile and was considering this psu https://planet-cnc.com/product/powersupply-48v320w/ . Its quite expensive , alternatively this one is 25% of the cost https://www.ebay.co.uk/itm/320W-48V-...cAAOSwMgdXzn13
Sounds too cheap for such a supply, has to be junk right?
Im just not keen on placing orders with china that takes 6weeks to arrive unless I know they are good/ worth the time (which is money after all)
Made lots of projects but have to say options on cnc diy is confusing - lots of Chinese fake parts , not clear manufacturer origins, model number differences dm860/L etc. A lot to digest
Cheers Jonny
I used a cheap 48V/400W eBay SMPSU for the steppers on a Denford star mill - with no problem; it's since been migrated into a conversion for a lathe (the star mill now sharing a control box/PSU with another mill). Yes, a big hefty toroidal transformer is better for this application but a £24 PSU will get you a long way down the road. If it gives you gip later on, replace it then. My guess is it won't do, given the size of your machine. £24 vs £100?, the volts don't care about the cost. Yes, the expensive one is likely (but not guaranteed) a better design. I'm sure it's shinier. But provided they both output the same volts then the rest of the system isn't going to mind too much.
Don't cheap-out on the rail, particularly with unsupported (supported is better!). My first router was effectively rendered useless for my intended use because of the unpredictable behaviour of unsupported rail.
Around 46Vdc.Quote:
Originally Posted by Andrewg
It's a very common problem with USB and you'll see lots of manufacturers say to use an external 5V source when they could use the 5V from the USB but it's so flaky it can't be trusted. There are other issues as well but just take my word it's best avoided if you want a relaible CNC machine and let me tell you there's nothing worse than a machine that locks up 15mins from the end of a 3 or 4hour Job.!!Quote:
Originally Posted by jonnycnc
25mm Steel box section isn't any good for a CNC machine, even a small one, I wouldn't build it with less than 50mm 4mm wall tube.Quote:
Originally Posted by jonnycnc
If you want a good machine there is more to it than just strength, Resonance and vibrations should be a BIG concern because if the machine vibrates and resonates this transfers to the tool and you get a poor finish and excess wear on the tool. No point wasting money on profiled linear rails if you going to fasten them to flimsy tubes.!!
#1 Use them on all axis.Quote:
Originally Posted by jonnycnc
#2 Contact Fred at BST automation, he sells good decent quality screws at good prices, he also sell genuine Hi-win rails and other products like energy chain etc. He's 100% trust worthy and a very good guy to deal with. Tell him we sent you from this Forum or say Dean from UK sent you and you will get a good price.
#3 Not sure what you mean when you say "keep it Low profile" but THE best way is to use a Toroidal transformer with capacitors and Bridge rectifier, I wouldn't advise Doddy's approach because it can give you issues and who want's to be doing this stuff twice.?
Do it right the first time and it will be cheaper long run and reliable. Taking the cheap route only cost's you long term and first time it bugs out on a job it's cost time and materials which will most likely be more than any saving you made.!
If a little concerned you could opt for this:Quote:
Originally Posted by jonnycnc
https://www.cnc4you.co.uk/Breakout-B...U-48Volt-12Amp
Akmost double the capacity. Yes it's more expensive but it's not that much bigger in size.
You know you're covered then.
I have these ballscrews on my mill:
https://www.ebay.co.uk/str/cyber-ebu...at=22348999012
Came properly spaced. Good thing about DFU is they can be tweaked with thin aluminium foil betwwen the nut/spacer, spacing them further to eliminate any backlash. Got mine right down.
Hi, what about Warp9 controllers? https://www.warp9td.com/
At one stage I was quite torn between the ESS and the UC300eth. The big difference between them for me was the ability to use UCCNC. Either can use Mach3/4 and be paired with some very capable breakout boards, giving 6 axis, plenty of IO and 24v signalling.Quote:
Originally Posted by Colin Barron
Okay, after some distraction looking at one of the most beautiful builds here for a very small steel frame design, I got a little daunted by the work needed on such a steel frame. Think it was Andy cnc (yellow and black paint job) I need to be realistic to my needs
I will only ever need to pocket out say 50mm thick Ali, or brass, woodwork and some intricate designs for electronic enclosures, microphone designs .Not in a high production capacity either, so finish more important than speed. I have spec'ed out the components for what I think will result in a build envelope of 290 x220 x 60 in z, which im hoping will be more than capable for my immediate requirements (and will have inherent value)
I want to check that i'm not going over board for such a small design that only needs modest soft metal cutting. To use 50x25 Ali box section (any recommendations on uk supply?) and essentially have similar design, guides to the red design in this post, only smaller footprint. Also the omio cncs seem quite capable although still larger than I need
http://www.mycncuk.com/threads/13547...hlight=omiocnc
My current thinking
500mm rails, 450mm 1605 DFU ballscrew kit, 4 HGH carriages - 2 each side next to each other (for main gantry slide, side mounted). The gantry will therefore have 450mm-about 160mm= 290mm travel, leadscrew will have about 305 of travel, ie travel limited by the main rails
300mm rails, 365mm 1605 DFU ballscrew kit, 2 HGH carriages (running on top and bottom face of gantry).Spindle head will be approx 80mm wide so travel here is say 220mm, the 365 leadscrew also giving about 220mm of travel
Not too sure about Z yet but possibly
200mm rails, 200mm 1605 DFU ballscrew kit, 2 HGH carriages for the Z. 200mm leadscrew gives about 55mm of working travel
800w 4 bearing air cooled spindle/ vfd, ER11 collet
3 closed loop 3Nm steppers https://www.aliexpress.com/item/3245...533b761fP4ER5j
48v 360w SMPS or ideally a 400va transformer (what capacitance is recommended? Can get pricy for caps at this voltage).
planetcnc ethernet controller/ software
3 off 3:1 gears and belts plus lots of other
Main bed- I was thinking 8mm Ali plate? , the machine can skim itself and drill a mount hole matrix.
Am I right with the ballscrew lengths above ? , I am under the impression that a 365mm (for example) assembly is its total length (i.e 300mm of thread, plus 11 at one end and about 50mm other for the motor mount?). And using a double ball nut which is 80mm means a 365mm assembly essentially gives me 220mm of workable travel? Is that correct ?
Also wonder if I need double ball nuts for all axis? They limit travel a lot
My main questions are do these sound reasonable components for my requirement and is the design linked above appropriate for such a small size machine? Looks neat but maybe there are better choices.
When building these type of designs how difficult is it to get all the guides true? I assume there is near to zero play in these carriages which makes me a little concerned about fabricating the rest of the machine
Apologies for lots of questions here, the amount of info on this site is a little daunting just now
Cheers!
Ok it's late and I'm tired so will make this replay short but ask me if want to know more.Quote:
Originally Posted by jonnycnc
Your idea of a machine to cut 50mm deep in Ali, brass etc and give high quality finish doesn't fit with your suggested build materials, 50x25mm Ali box section is just not stiff enough cutting Ali and giving high quality finish.
You need much stronger machine that won't resonate if you want a high quality finish. Thick walled steel is the best way to go.