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Hi All
Big question I know,but just wondered what every one is using.
I had hoped to modify an old driver board but that went up in smoke tonite, which has shown me how difficult it is to fault find on a single board and has put me off getting one of the "all in one boards" from china
I need 3 axis to drive 2 phase bipolar motors wired in parallel at 2 amp per phase, any ideas?
Cheers
I use Motion Control Products MSD542 drives. They have worked fine for around a year now.
http://www.motioncontrolproducts.co....&products_id=3
Arc sells the same driver cheaper and it includes VAT.
http://www.arceurotrade.co.uk/Catalo...tepper-Drivers
Are they the same driver John ? or the PM range ?
i'm using MSD542 as well, i'v used the routoutcnc drivers as well.
I use the Motion Control Products MSD542 ones, I think they are made by Leadshine in China (M542 OEM model) and sold under different brandnames
Leadshine m542
They are not the same driver, close but not the same.
As allways in china you will find copies of everything.
Leadshine are the largest manufacture of stepper drivers in china, and there are lots of copies of their drivers, some good, some not.
by the way i will match Arc euro trade prices as long as i have them in stock.
You may also want to try our PM752 for higher current motors, it is a very good driver and goes all the way up to 70V.
Actually they may be the same, after looking at their webpage.
Now you tell me......:heehee:
I've decided to roll my own, with the help of Tribbles of course. 4amp, idle current reduction and full power on half step but no micro stepping.
If it dosnt work out then £30-40 an axis sounds great :smile:
Hi Lee,
My all in one packed up ages ago, and put me off finishing my machine. I have decided to give it another go now. All I am missing is the motor drivers. Do these boards work with Probotix H23 - 400 4 wire motors ?. Thats all the info on the motors. I didnt buy them myself.
Quote:
Originally Posted by Lee Roberts
What ones? Can you not email them and get the spec sheet for the motor, i found the 8 wire version: HT23-400-8.pdf, most drivers will run motors but you want to match them really.Quote:
Originally Posted by dudz
.Me
Attachment 8547
This is all I can find.
What rating or output is your PSU, if you dont want to change that as well then you need to match your drivers to that so they dont go pop!, consider if or not you plan to upgrade or use the new drivers on another machine in the future.
.Me
output on PSU is 24v 8.3A 50-60hz /http://www.interinar.com/fs-20024-1m.html
na I wont be using on another machine.
Why are they better? are they not overkill for what he needs and his PSU being only 24v ? What about the duty if they get seen coming in?
.Me
What is Zone 1 and Zone 2 ?
It looks good but the circuits have no cases. So I would have to build something.
Quote:
Originally Posted by Lee Roberts
The Zones are for postage.
.Me
Yes they are overkill but being overkill means they are not running flat out and plenty in reserve.Quote:
Originally Posted by Lee Roberts
Plus they are in a case, post paid and cheaper.
That M542 design has been proved over many 100's of thousands of units built.
I have bought loads of these, none have ever hit the radar, usually they get declared as a USB cable at $10
Patrick,
Have a look here: Enclosures, you could also get a System4 board and build yourself a nice control box to house everything :).
Just an idea :thumsup:
.Me
Are there no reliable "all in ones" ?... It just seems alot of accessories just for one job.
I can solder and repair boards at a push, but I'd rather just plug it into my pc/cnc , turn it on, and use it without all the whistles and bells. Maybe I am just lazy ?
Only all in 1 is the Gecko 540
G540 4-Axis Motor Control
Unfortunately what with taxes etc it doesn't come cheap
Gecko will not sell direct to you as they have a UK agent, Charter controls who's web site is down at the moment.
You can but off Ebay.com for about £190 plus £30 shipping but expect to get hit for about £40 duty on top of this.
You can connect a lot of wires for this price plus if it does go wrong you are faced with shipping it back etc.
Separate units are far better
The "all in one" that I had was fine for about 3 months. We have power surges here every week and I think this is what fryed it.http://www.easy-cnc.com/3axisdriver.html
The one that you mentioned.... Is it likely to go wrong if wired correctly ?
I was going to buy this one ; CNC Router DIY Kit 5 Axis Breakout Board + 3x M542H Stepper Motor Driver 1A-4.5A | eBay
If it is compatible with my motors and PSU. Seems simple enough, and in cases
You are just buying what I posted to but you are prepared to pay £149.82 for it.Quote:
Originally Posted by dudz
However if you buy three of the drivers i linked to [ which are exactly the same ] for £24.76 = £ 74.28 and this breakout board and lead
Upgraded 5 Axis CNC Breakout Board Stepper Motor Driver + 5V USB Cable + Mach3 | eBay
Look familiar ?
For £10.99 you will have spent £85.27 to get the same thing.
However if you insist on spending more then send me £140 and I'll bung 3 drivers, a lead and the breakout board in the post first thing tomorrow.
I don't mind and you get to save £9.82
John i have a question for you if you will.
A member who i dont think is around anymore once said to me that, if a motor is rated at 3a per phase that you only need to make an allowance for this of about 50% because the motor is unlikely to ever require its full amps rating, I think he did say its posable but you would have to be seriously working the motor for that and its just not likely.
Is that true?, also dose a motor draw more current when its doing rapids vs when the machine is cutting into stuff or dose it draw a steady amount consistently through all operations?
Thanks.
Lee the accepted figure is 2/3 for a parallel wired motor and 1/3 for a series wired motor.
These are figures that Marriss Fremanis at gecko drive came up with and are repeated as law.
So a 3a motor in parallel take 2a and 1a in series.
However I have had clamp ammeters fitted to power supply leads and running a system under rapids and loads i have never seen these figures, they have always been far less.
In fact in many cases the figures have been very small, far smaller than I would have imagined so the 50% is a far more acceptable figure.
One machine I used to convert I used 650 VA transformers at 50 volt AC, in a cost cutting exercise, due to rising copper costs, I dropped to 500 VA and saw no difference, a drop to 400VA still didn't make a difference but going to 330 VA did,
So the drop from 650 VA to 400 VA halved the transformer cost.
Is there any benifit from having a USB instead of Parallel port ? ...I found this 3 Axis CNC USB Card Mach3 200KHz Breakout Board Interface Speed: 48M Win 7 | eBay
I know it is more expense, but is it better quality ? and are there benifits ?
Not a lot to choose. More expensive and no better than a decent PP card but has the option of being able to use laptops and any USB interfaced computer.Quote:
Originally Posted by dudz
There is an argument that PP port equiped computers are dying out, it is true but there are still 1,000's about for not much money that the argument isn't valid.
I buy Dell DX260 in bulk.
http://imgusr.tradekey.com/p-2543013...x270-gx280.jpg
No mine but this is how they are offered, cost about £20 each with an XP license on them.
However we are trialling a couple of the USB boards, first one will be later this month and I expect that the price will drop.
The one shown is from a different company that the ones that developed them,
Ok.... I bought 3 of these , CNC Micro-Stepping Stepper Motor Driver 2M542 Bi-polar 2phase 4.2A Switch | eBay and I bought this ; 3 axis CNC USB Card Mach3 Breakout Board Interface 200KHz windows2000/xp/vista | eBay
I could of bought the cheap one but I really like the idea of using the USB instead of the PP port. I will let you know how I get on. Thanks both of you for all of your help.
John,Quote:
Originally Posted by John S
I have a couple of old laptops laying about is there any downside in using them? or should I be investing in a cheap old dell?!
Shouldn't be taken into account the motor amps/torque vs. the machine weight/working material?Quote:
Originally Posted by John S
If I put 3A motors on a belt driven PCB milling machine it is impossible to use that power assuming to have idle-current reduction.
I think the 60% rule for the power supply works only with toroidal transformers which have an instantaneous power at least 25% higher than the nominal, and with one PSU for all motors because it is unlikely to have all axis under high loads at the same time.
John, what rated current had the motors and drives for your conversion where you used reliably a 400VA transformer?
Joe,
Truthfully can't answer this question at this time.
Using laptop with parallel port is a no no but the USB card 'should' be OK.
So far although we have two cards neither has been tested because I'm in the process of converting a manual mill to CNC and it will be used on this, probably about 2 weeks away from testing given this has to fit in with my regular work.
It will be tested on a Dell to start as the 'test bench ' is so equipped but I'm also interested in seeing if the laptop will run it OK
Part of the reason for your low readings is the sample frequency of the clamp meters is low relative to the frequency of the current the motors are drawing, so it tends to miss the peaks and generally not be reliable, especially if the meter is not true-rms. An oscilloscope reveals a lot more.Quote:
Originally Posted by John S
However, it is still true to say the rms current, and therefore power drawn, is substantially lower than the 2/3rds 'rule' implies. It's easy to show why - just look at the motor ratings to work out the power. For example the common 3Nm motors require 4.2A and 2.73V. Power is current multiplied by voltage, so P=4.2*2.73=11.466W. That's per phase though, and it's a two phase motor, so 2 times that which gives 23W. You're driving it from about 70V, so the current is pulsed such that the mean power does not exceed this rated power. Same formula again, so the mean current is I=P/V=23/70=0.33A.
That's why you see a low current (about 0.33A) per motor, not 4.2A or some significant fraction of that. The reason it helps to have the power supply rated for quite a lot more (i.e. 2/3*4.2) than this anyway is that the peak currents can be substantially greater, so you need a transformer capable of delivering that. That's not the only way to solve it though.
Me too. Be good to hear how it gets on... Thanks JohnQuote:
Originally Posted by John S
Any news on this John?Quote:
Originally Posted by John S
Still 2 weeks away <g>
Problem is my day job is emergency repairs and I never know what comes thru the door to upset planned jobs.
Starting to wire the box up Friday, fingers crossed and then sort the machine out.
machine is all converted mechanically, just need covers and bellows re fitting.
OK be glad to hear when you get it up and running. Cheers
What's the delivery time like? I bought some from the same seller last December and they took 7 weeks to arrive. Might of been due to the Christmas post, etc. I am just wondering if they "normally" arrive sooner?Quote:
Originally Posted by dudz