On going chinese 6040 problems

ok just been down the the cave to try again. I have set things like this K1 n K2 set back to 2 again. i set the setting to

steps per = 80
velocity = 1400
acceleration = 150

The Torque is a lot better set like this . I can run with out stalling and it seems faster than before.
I haven't cut anything yet with it like this but i tried to stall the motor by hand and i can but it takes a lot of force to do so.

what is the difference between velocity and acceleration ?


Any way it seems we are getting some where. I will try cutting something tomorrow and see how we get on.

In the long term i think upgrade is in order at some point.
I would like to say thanks for sticking with me on this. I seem to be learning so much so fast. I should be used to that being a heating engineer . All the help has been much appreciated

Velocity is just the maximum speed your machine can work at, acceleration is the rate of change from one speed to another, just like your car really.

Also there is this from the Mach3 documentation;

"If you can’t seem to get the motors to run smoothly there are a few things to check, first the easy one: Some motor drives need to have a longer step pulse and this can be set by changing the Step Pulse setting. "

I've tried a few values here for my own machine but found no difference I could detect but I'm using digital drivers, it might though make a difference on your machine.

It is strange that mach3 shows 1-5 us in step pulse but the instructions say set it to 10. so i have it set at 10. i will look at that tomorrow and see if it make much deference.

Ever other forum i read say change the board to a Gecko G540. wondering if its worth it and with it take the 4 wire steppers as i have 6 of them now haha

HOLD on just looked atmy video again and noticed my step pulse was set at 2. but the instructions say it needs to be set at 10 . I just found a post that said "if the step pulse is too short the motors don't respond at high step speeds" So im guessing that 2 is a short pules ?

I think it's the same as putting extensions onto your house, it gives you bigger and better but if you're not carefull you can exceed the local house price ceiling. In other words you can upgrade and add better parts but the total cost might come to more than it's worth and you'd have been better starting from scratch or selling what you have and move to a different but better machine.

As the saying goes, "You can't polish a turd" or for those of a sensitive nature, "You can't make a silk purse from a sow's ear"

Quote:

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Originally Posted by amxen

HOLD on just looked at my video again and noticed my step pulse was set at 2.

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Good observation, more things to try !. Make a note of what you change and the result, so you can look back and determine the best settings.
Also I think it's fair to say most people set their microstep to 1/8 so aim for that but if the machine can't manage then reduce it like you did.

Mike Glad to hear you now have some movement and are getting there. If you can sell your other kit back on EBay I would because you can get much better motors and drives than those you have. Or at least sell the motors and look at the ones from the link I posted. Good luck. ..Clive

OK last testing for this evening . I just wend down and changed it all back to how it was and then changed the step pulse to 15 and the dir pulse to 10 . Dont know why them numbers i just thought i would see what happens. I now have it set like this and it seem not to be stalling

steps per = 320
velocity = 1700
acceleration = 160
step pulse 15
dir pulse 10

i have no idea about the step and dir pulse but it seems not to be stalling like this . and i cant stall the motors by hand .
I did try it faster (1800) but it did start stalling so i wound it back down.

gonna try cutting some mdf tomorrow. This was the first thing i cut when i got it just to test it Attachment 13354

Ok well I think you main problem is coming from the BOB and the fact it will have slow opto isolators. This is why your getting better results using higher step pulse.
Try running in Sherline mode and see how it goes because all thou your set at 10 -15 your not getting that as Mach in normal mode doesn't go that high.? Sherline mode gives you wider step pulse so gives the opto's more time to work. You'll find it in port's n pins on first page near Kernal speed. You'll have to restart Mach3 and retune motors.

To be honest you have several issues here all of which can only be cured with a bullet or a mallet.!! . . . . Crap celectronics give crap results.

With the high inductance motors you have and only 24Vdc running rubbish drives thru a piss poor BOB then in all fairness your near the end of what should be expected. Sell the lot and buy decent drives. Don't go for the G540 as there are better options for less money and the Gecko is restricted to 3A motors to use it's full capabiltys.
Your main issue with slow speed is lack of volts but don't go giving the drives more because you'll fry them. Max they will stand is 36V and they won;t like that for long before letting out magic smoke plus 36v isn't much better than 24V with these motors and you'll need 50V drive running 44-46V to get any decent speed from them.

Now with the stalling and micro stepping then after the short pulse width problem then resonance is the next issue you'll be encountering. Resonance affects motors in differant ways and is often worse when sat on the bench.
Also the micro stepping plays it's part here as well. Setting the Micro steps too near to full Step 1-1 often makes resonance worse so stalls more. Setting higher makes the motors run smoother so less stalling but this comes at the cost of many more pulses required which in your case makes things worse because your Rubbish BOB can't keep up as it is.!!. . . So it's a double edge sword I'm afraid.!! . . . Fubar'd in both cases.!!. . . Time to get Timmy out.!!

This is why decent electronics and the quality of the pulses being sent to the drives/motors is so very important.

Thanks for that information Jazz . When i do upgrade the electronics what BoB would you go for ?


The wonderful world of cnc, I only wonted to cut stuff and ended up being an electrical engineer

Some reading,

http://microsoftwindowsblogger.blogs...nel-speed.html

Quote:

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Originally Posted by amxen

Thanks for that information Jazz . When i do upgrade the electronics what BoB would you go for ?

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Well at the cheap end then I'd look at Roy's boards at DIYCNC they are ok for the money and I've used many of the opto boards. At the other end then and by far the best BOB on market for the money is the PMDX126 but this can only be bought direct from PMDX. It cost's much more but there's a reason, It's quality.

If you want good quality ALL-in ONE board with Digital drives and spindle speed and BOB all built in then you want the Lead shine MX3660 from Zapp http://www.zappautomation.co.uk/elec...ng-driver.html

Though it's an all in one board the drives can be replaced individual if one is damaged.
The drives allow upto 6A motors run at 60Vdc thou in real use you'd run around 50-55Vdc for a safety margin. The drives are Digital so very good at handling resonance and give very smooth movement compared to cheap analog drives with advanced features to help with handling pulse smoothing etc. They have standard current reduction at stand still etc to control motor heating but in general they run the motors much cooler because of the way the handle current.

No BOB required it's built in. Also Comes with 10V Analog spindle speed controller built in so can control spindle from control software or G-code.

This Digital Combo board knocks the socks off Gecko G-540 IMO and yes I have used G540 infact I have one in front of me now, because it can be used with much wider range of motors due to being 6A and the extra volts allow more speed !! If needed.!! . . . but the only draw back is it's only 3 axis not 4 like the gecko.

This is a good Combo board that will take with you to another larger build if required and there's virtually nothing to setting it up, close to plug n play as it gets.

Thanks for that Jazz . it seem to be running well now. with the changes i made yesterday. happy days for now.

Well im thinking i will have to upgrade it at some point going by most of the posts about them.

So i have been looking at this http://www.diycnc.co.uk/html/system45.html and was thinking i have this kit i got from aliexpress http://www.aliexpress.com/snapshot/6104230003.html ( was gonna make my own cnc ) and was thinking would this diycnc board be ok to run these stepper motors and utilize the 36a power supply from this kit.

Quote:

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Originally Posted by amxen

Thanks for that Jazz . it seem to be running well now. with the changes i made yesterday. happy days for now.

Well im thinking i will have to upgrade it at some point going by most of the posts about them.

So i have been looking at this http://www.diycnc.co.uk/html/system45.html and was thinking i have this kit i got from aliexpress http://www.aliexpress.com/snapshot/6104230003.html ( was gonna make my own cnc ) and was thinking would this diycnc board be ok to run these stepper motors and utilize the 36a power supply from this kit.

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Mike The kit you are referring to will still only take 40V psu so yes it will take the 36V psu you have but you are still throwing good money after bad. To run the motors you have you will need at least 50V psu. If you are up and running now how about getting some experience with the machine and cutting a few parts and then you have a better idea what you really want.
.
I am not trying to put you off, the trouble is these kits that you have seen are always a compromise and are put together with a mismatch of bits and you can do a lot better with sourcing the parts separately. As have been said many time on the forum a good place to buy the motors is cnc4you or Zapp and the drivers from aliexpress. ..Clive

Im trying to understand whats wrong with the stepper motors Clive. Is it that they are trash or that they need more power to run them than i have or need. Are they for a bigger set up. Or just junk

Thanks mick

Ok well I'd forget Roy's System 45 as it's no better than that kit from Ali express.

First the Aliexpress Kit is a USBCNC Motion control card with BOB combined. This means you'll have to use the USBCNC control software not Mach3. This is not a problem just making you aware.
The fact it's Motion control card will take away most of your Pulse issues in one go.

Regards the Motors then those listed are 4 wire but it doesn't say if they are series wound or parallel, I'd guess at series given the amps and inductance. The more common 8 wire Hybrid motors can be wired either way but with 4 wire your stuck to what the manufacturer winds them.
Being series wound means they require much more volts to get any resonable speed from them. Motors wired in series give higher torque at slower speeds but quickly run out as the RPM's rise. This is why the 36Vdc isn't really man enough for these motors to expect any speed from them.

The Kit drives can take upto 50Vdc but again in practise you need a safety margin. The reason you need a safety margin is that steppers effectively become dynamos when de-accelerating and this energy gets passed back to the drives and is known as back EMF. So if you run at the drives Max voltage you will damage them.
For this reason running lower voltage is recommended. How much lower does depend slightly on the power supply type. Regulated Linear type supplies need to be run at lower volts than toroidal type supplies due to how they handle returning current. It's for this reason why Unregulated supplies are prefered and in particular toroidal transformer type due to the capacitors better handling returning power. Toroid supplies can be run closer to drives limit.

The drives in this kit are 50Vdc max so I'd run them around 42-44Vdc with an Unregulated supply. This will give the motors that bit more voltage required to cover the higher inductance. Still not ideal but better. 70vdc would be much more suitable but your drives wouldn't be too impressed. . Lol

Now personally I'd just think about changing the PSU for toridial supply which are very easy to build or can be bought and run the drives at 44Vdc. This will get you going at Ok speeds and will be good for learning without costing a fortune.

Quote:

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Originally Posted by amxen

Im trying to understand whats wrong with the stepper motors Clive. Is it that they are trash or that they need more power to run them than i have or need. Are they for a bigger set up. Or just junk

Thanks mick

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Mike No they are not trash, just not suited to the power supply and drives these motors have inductance of about 7mH, per phase now the ones that I use and a lot of others are these:-http://cnc4you.co.uk/resources/60BYGH301B.PDF which have an inductance of 3.2mH (less than half) I run these at 68V. As Jazz has said that kit has its own software and not Mach3.
If it is your intention to build another machine in the future it might be worth it to sell your kit and start again. But first have a go at machining and having fun making a few parts with the 6040.
If you really want to change the drives in the 6040 for the one's in the kit then either get a new power supply linear type or build one (if you are confident with mains voltage).
Either way we can try and help you through this learning curve. ..Clive

Hi Clive. We'll I have reconstituted someold pc power ssupply's that I use to run my 12v battery charger this give me around 20a. Good for a cheep bench 12v supply. They have the added advantage of having 5v and 3v if I need them. But that's as much as I have done. I know my way around a multimeter thow as I'm a heating breakdown engineer. I will have a look on YouTube and see if I can find a video on building a linear supply that will give me what I need. Thanks for all the input.

Quote:

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Originally Posted by amxen

Hi Clive. We'll I have reconstituted someold pc power ssupply's that I use to run my 12v battery charger this give me around 20a. Good for a cheep bench 12v supply. They have the added advantage of having 5v and 3v if I need them. But that's as much as I have done. I know my way around a multimeter thow as I'm a heating breakdown engineer. I will have a look on YouTube and see if I can find a video on building a linear supply that will give me what I need. Thanks for all the input.

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You just need a few parts:
You can get them from http://www.rapidonline.com/ say 2 of these http://www.rapidonline.com/Electroni...tor-11-3121and one of these http://www.rapidonline.com/kbpc5006-...00v-47-1012and a transformer like this http://www.rapidonline.com/vigortron...-0-50v-88-3844 but to suite your voltage. Remember to multiply the output of the transformer by about 1.4 to get to the DC voltage you require. ..CliveAttachment 13363

I'd like to know this, with the settings now at their optimum does the machine perform adequately. ? i.e. within it's designed capability.

Eddy. I'm not sure if If it's running at its designed optimum as I have not had time to test it. I ran some code to cut a sign from 6mm mdf last night. Like the photo of the one I have posted here before. It seemed to not miss any steps it cut very clean and quite fast. The sign was about 10inch long and 5inch tall. It had no problems and took about 20 mins, but I only have the plunge set at 1mm so it took 7 trips to complete the final cut out. but that was planed and expected. If you let to know who I should test its performance I will gladly carry that out for you.

Eddy. I'm not sure if If it's running at its designed optimum as I have not had time to test it. I ran some code to cut a sign from 6mm mdf last night. Like the photo of the one I have posted here before. It seemed to not miss any steps it cut very clean and quite fast. The sign was about 10inch long and 5inch tall. It had no problems and took about 20 mins, but I only have the plunge set at 1mm so it took 7 trips to complete the final cut out. but that was planed and expected. If you let to know who I should test its performance I will gladly carry that out for you.

I don't know what it's designed to do but it sounds like you are not far away, why not just use the machine as it is until you find your requirements have outgrown it.

Quote:

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Originally Posted by amxen

It seemed to not miss any steps it cut very clean and quite fast. The sign was about 10inch long and 5inch tall. It had no problems and took about 20 mins, but I only have the plunge set at 1mm so it took 7 trips to complete the final cut out.

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To be honest you haven't really defined if the machine is running correctly because your not actually cutting at correct feed rates. 1mm DOC in MDF is hardly a challenge or test. I suspect that if you tried to cut MDF at the correct feeds/speeds/doc then you may get very differant story.

With a Shallow DOC then you really should be running high feeds rates or very low spindle speeds to give any decent tool life. Your setup 99.99% sure won't run the correct feed rates for 1mm DOC without stalling motors and if you increase DOC then chances are it will struggle if it's still not setup correctly. Spindle speeds are about the only thing your in control of and this alone isn't enough.

With MDF then you should be able to cut much deeper and still maintain decent feedrate even with these types of machine. Minimum DOC should be 50% tool diameter and 100% + is common in MDF with carbide tooling. Can't say on feed as don't know what you cut this at but I suspect it will be well short of what it should be.? Minimum feed in MDF would be 2000mm/min and thats with lot deeper DOC IE: 3mm cutter = 6mm or more.!

So just because your cutting doesn't mean the machines working OK. Tool life is something you need to consider and cutting like this will drasticly shorten tool life, esp in MDF. Sharpness of the tool greatly affects finish quality so you very quickly lose finish quality when cutting with wrong feeds/speeds/DOC so it really does pay to spend some time and set the machine up correctly.

Interesting. The supplier is offering a partial refund on the machine. As I told them I was going to put a PayPal claim in . If they do I will up grade what's I need to with the cash they give me back

ok so im still having problems with this thing jamming . So i put a paypal claim in and this is what i got back from paypal

To continue with our investigation, we need documentation to support your
claim that the item is damaged or significantly not as described.

Please obtain a document from an unbiased third-party, such as a dealer,
repair shop, appraiser, or another individual or organisation that’s
qualified in the area of the item in question (other than yourself), which
details the extent of the damage or clearly explains how the item received
significantly differs from the item that was advertised.

This document must be on a letterhead that includes the name, address, and
phone number of the individual, business, or organisation so that we may
contact them if necessary.

If applicable, the document should include a serial number and description
of the item and the cost required to complete any necessary repairs.

You can upload this document through your PayPal account. Here’s how:


How an i gonna do that i dont know any one that fixes cnc machines and i cant really post it to some one now can i ?

hi,

i had same problem as you. the fix for this: The problem not with your setting in mach3 or the driver board.

The problem is the wiring. your wiring need be fix.

1. the wiring a attach to the power supply with tire wraps. That's A NO NO. remove it from power.
2. In that box, You need use 4 wire shielded cable for each stepper motor, from contoller board to the 4 pin connectors.
3. You need to put EMI AC filter. remove the one that come this box it's cheap chinese make. You can one on amazon $10 USA made.
4. You need to use 4 wire shielded with GND wire. 4+GND, For DC power. 2x red/2x blk plus shielded wire for GND.
Don't get confuse with the AC Ground wire and DC Ground, They must be separated.

5. And Most important (REMOVE) VFD from Box, This VFD is **Shielded** attach to outside with plastic mounts. No metal contact between VFD and Box Controller.

6. The stepper motor cable's from Box to stepper motor MUST be shielded cable 4pin wire + shielded GND.

I did this my 6040 and has been work 100%

Good Luck.