Reply with QuoteOk, then the problem is not missed steps.
What happens is the motor stutters or stalls completly, then starts moving again. Guess it could be a computer problem.
ok
missed step is
tell the mill to cut a circle
tell the mill to cut the same circle in the same place
again and again and again
if you have missed steps the circle will no longer be in the same place or even round any more
its when the stepper should move but dosent
most of the time its the controller that causes it not the motors or the mechanical items
Ok, not missing steps.
Ok, then the problem is not missed steps.
What happens is the motor stutters or stalls completly, then starts moving again. Guess it could be a computer problem.
from what you have said it sounds like a driver / breakout board problem or electrical interference
try to reduce your drive speed to 1/2 what it is and try again
Tried that and it keeps doing it.Originally Posted by Adverse Effects
I noticed on Mach 3 in the feed rate area, Units/Min falls down rapidly when it's stuttering, so since there is no feedback from the machine I guess this units are the units sent not the units "moved" so maybe it is a problem with Mach 3 not sending all the pulses? There have been no changes to the PC, only have Mach 3 running, but it's an old machine!
Will do a complet check of the PC.
Old machine doesn't matter, the processing power for simple testing is not important, the only thing at the pc end that matters is the Mach3 kHz setting, which is usually 25kHz from memory, and the logic signals, which are very rarely, ever a problem. What I suspect your problem will be is missed signals due to the bad earth and analog/digital grounds, and the buffer/interface board. Until you resolve all the ground plane issues, and then the buffer/interface circuitry, you won't get anywhere I'm afraid. Even the opto circuitry which is supposed to help level logic signals, is so badly designed it provides no protection and some boards degrades the signal path. Out of curiosity have you powered up the spindle in it's Z mount while the machine is moving? Generally with these controllers the spindle powered up puts so much garbage back in the circuitry it moves on it's own accord like a drunk at a wine tasting.
You could seriously end up spending the next 6 weeks trying one after another, but in the end it generally comes down to, buy a Gecko or Lini, or similar.
It's absolutely unfathomable to me why all of these machines come with a completely useless controller. Even the few users who have gotten them sort of working, after a fashion, and within strict power up guidelines to avoid blowing the chips, don't have the great things good controllers have like mid-band reasonance damping, true micro-step, short circuit protection, idle holding current, etc, etc.
cheers,
Ian
It's a state of mind!
I give up!
Yes you are right and I really don't have the time or patience to sort this out. I think I will go with the Gecko.
Thanks Ian & A.E.
I bought a Chinese 6040 and based on the recommendations in this forum never even ran it with the included controller. I immediately swapped in a Gecko G540.
That worked very well in my dry runs, but as soon as I powered the spindle up, I started to see glitches. I changed the stepper motor cables to shielded cables, tied one end of the shield to ground, and haven't had a problem since.
I think changing the stepper cables is a must.
Last edited by Qubert; 07-10-2012 at 01:40 PM.
i changed the cables (all 3 stepper's and spindle cable) first and it got rid of about 2/3 of the problems
but the G-540 fixed all the rest and allowed me to drive the mill 2 times as fast
It sounds like a good idea to change the cables, but wouldn´t be enough to only cover the cables with aluminum foils and adhesive tape and connect the foils to earth? Wouldn´t that be an easier and cheaper solution?
may be cheaper and may work but i am anal about how it looked LOL
With a shrink tubing outside, it wouldn´t look so bad..
Generally it's a good idea to have the earthing conductor (usually a shield with a drain wire) in as close proximity to the cables running data, to help eliminate the crosstalk and increase noise immunity, having it on the outer can be less effective on noise immunity. This article explains why foil isn't always the best form of shielding, especially as it's more suited to higher frequencies than you'd get on a CNC machine, and the difficulty in obtaining a good earth connection without the use of a drain wire.
cheers,
Ian
Video Cable Shielding -- Blue Jeans Cable
Another interesting read:
http://www.shield.net/files/catalogue/support/2.4.pdf
It's a state of mind!
Any links to inexpensive cables and connectors which would work?
The connectors are readily available from the Chinese suppliers at ridiculously low prices for small or large quantities on Ebay, and are identical to the ones that come supplied with the spindles and steppers, and oddly enough, also identical to the supposed locally supplied ones which were inferred as superior quality but were clearly just overpriced imports (for those who believe they are inferior!). I've bought many, many types over the years and had no issues with the quality or solderability of the Chinese ones.
The cable is a bit harder to get here in Oz, don't know about where you are, this one from Homann Designs is the standard one we mainly get from his site or Jaycar in OZ:
http://www.homanndesigns.com/store/i...roducts_id=102
When I make my cables I actually terminate the short stepper cable with one of the socket, and then make a cable to go to it so the stepper can easily be disconnected when required. Also helps with swapping over axis's for testing.
cheers,
Ian
It's a state of mind!
4 Core 22 Gauge Screened Flexible Cable (per/m) - $2.64 : AusXmods
4 Core 22 Gauge Screened Flexible Cable
Flexible screened control cable 4 core x 22 Gauge suitable for both Nema 17 and Nema 23 stepper motors or for any other application where electrical interference is an issue.
I simply reused the connectors from the original cables.
I don't have a clue where to find cable in Australia, but I bought mine in the US here. The cable linked to be Adverse Effects is a better deal.
Last edited by Qubert; 07-11-2012 at 03:40 PM.
your link is an aussie shop
Homann Designs
20 View St
HIGHETT 3190
AUSTRALIA
Too funny. I didn't have a clue I had a clue.
What are your experiences with eBay and/or Alibaba etc.?
I am thinking about buying a Chinese 6040 CNC, and I have come up with a list of eBay resellers (I live in Japan).
eBay reseller__________CNC 6040____Ship to JPN__Total
---------------------------------------------------------
equipmentwholesaler1___US $970.00 + $898.00____$1,868
rumei-shopping_________US $882.00 + $986.00____$1,868
qiandingzhensatisfaction_US $1,796.00 + $99.00____$1,895
industry-village_________US $1,769.00 + $130.00___$1,899
world-etrade___________US $1,201.00 + $694.00___$1,895
amonstar______________US $1,699.00 + $299.00___$1,998
- It woud seem that some of the above are supposedly shipping from Australia, and some from the US.
Since I am in Japan, I would think that shipping directly from China to Japan would be much cheaper, but that does not seem to be the case - does anyone know why?- Is there any benefit (or drawback) to purchasing the 6040 CNC directly from one of the makers on alibaba.com or madeinchina.com?
I would assume that eBay is the more trusted route, as sellers want to maintain their positive feedback (all of the above have 99%+ on eBay).
