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 Leadshine Dm series drives 
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Joined: Wed Jan 20, 2010 4:50 pm
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Post Leadshine Dm series drives
Hi

I'm making a new topic here because there has been some discussion about the performance of Leadshine DM432c in particular.

So to kick off I have been setting up a small animation rig for a shoot using DM432c drives.

The first part of the rig is a small slider with 45cm travel driven by a lead screw with a 47mm long nema17 motor directly coupled via a spring type coupling to the lead screw input shaft. The slider has a small pan tilt head mounted, weighing a few kilograms.

The Leadshine drive is powered by a 35vdc analogue unregulated transformer PSU.

I ran the test with the drive set to 1600 ppr micro-stepping. (8x)

The drive is set to 1.6 amps peak current. At this setting the motor gets slightly warm when running frequently, but at rest remains cool to the touch.

I ran some tests with varying rates of acceleration and maximum velocity. The move profile window below shows the final test move, the black coloured velocity curve indicates the max velocity is 38.83. This is actually in cm/seconds and is the peak velocity mid way through the move. Since the axis was calibrated at 2655 pulses per unit (cm) then the max pulse rate = 2655 x 38.83 = 103093.65.

The maximum acceleration is also indicated at ~ 75cm/sec/sec - from the blue accel curve you can see accel is ramped up and down as a result of smoothing, which reduces jerk at both the start and end.

Doing a bit of math this is quite impressive for a stepper motor at ~ 3,866 rpm. With more aggressive acceleration it still reached 2,500 rpm.

Conclusion : The DM432c is quite adequate for small motors and rigs, and certainly more than adequate for animation... though results will vary depending on the motor and the efficiency of the mechanical system..


Attachments:
Move Profile.JPG
Move Profile.JPG [ 48.24 KiB | Viewed 15416 times ]
Slider.JPG
Slider.JPG [ 105.04 KiB | Viewed 15416 times ]
Motor Detail.JPG
Motor Detail.JPG [ 89.81 KiB | Viewed 15416 times ]
Fri Mar 11, 2016 10:07 pm
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Post Re: Leadshine Dm series drives
Hi, Gerald,
Hopefully this topic will turn into a useful asset, do you use the Leadshine tuning software, it would useful to see a screen dump of the setting values. Also did you just Auto tune and or manually tweak the various tuning settings?

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Sat Mar 12, 2016 12:50 am
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Post Re: Leadshine Dm series drives
Hi Mike

It was mostly default settings. The tuning parameters mainly effect low speeds.

The software version I was using didn't enable all settings. In future if I find more useful information on this I'll add it, the software help is pretty ordinary let's face it...

At one stage I did reduce the p gain manually to try and reduce resonance (auto set it to 6,000 which is very high) - though really it was resonance in the lead screw which is a very direct mechanical linkage and quite unforgiving. I think a belt drive between the motor and the screw would help to reduce this effect.

Basically if there is resonance there are two initial things to do.

1. Lower current reduces resonance, though top speed is also reduced.

2. Adjust the P gain and or I gain... reducing them has a similar effect but harder to judge.

After that, the notch filter sliders only work at very specific frequencies which may not always relate to your system. Ultimately there is no one right way to set things - just one that works for whatever you need...


Sat Mar 12, 2016 1:07 am
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Post Re: Leadshine Dm series drives
Hi Gerald i am going to run more test when i get the DMC . Still not turned up yet i imagine British customs are using it as a door stop :( . The arduino Df combination is to limiting on pules rates and i cant adjust acceleration .
My original tests did use four different motors though and performance on all was well down compared to running CWD 556. Two of the motors were Nanotecs which i view to be good quality . The issue was slight better on the 17s though . Initial test and discussion can be found here viewtopic.php?f=24&t=13156
Does Mantis come with a manual ? What happens if i was to supply a rig to somebody running Mantis do they just have to work their way through it by themselves.
Dont think many people will want to spend that time when a production is running.
D1


Sat Mar 12, 2016 2:17 am
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Post Re: Leadshine Dm series drives
Hi D1

Re "quality" The majority of stepper motors are rebadged from the same factories in China I think. Only a few brands like Vexta are still made in Japan and may have more refined characteristics. I recently tested a small Vexta motor and it did have less resonance issues than a comparable chinese motor.

But in most cases the significant differences between motors are due to the windings. ie. the resistance or inductance. In the old days drives were more particular about this rating and wouldn't work at all if the inductance was out of range. In general, higher inductance windings were designed for higher voltage drives. In the Leadshine and other drives, the auto gain setting attempts to compensate for this factor.

Aside from that I prefer not to make a competitive comparison, but to look at what the drive and motor can do in specific situations. Testing in situ with working equipment is the most relevant and revealing.

Personally I prefer to use a drive that is relatively smooth, quiet and doesn't heat the motor too much, and I don't mind paying a bit extra for that. If noise is not an issue then the options are wider ...


BTW D1

Off topic a little, but if someone is serious about buying Mantis I will send additional information and answer any detailed question they might have. I can also send the software for evaluation. Typically the responses indicate Mantis is easy enough to get into quickly and the system is much appreciated for its depth...

Also, I wouldn't advocate learning new software while a production is running - though it really depends on the operator and their experience. There are always some who need details explained, while others will click fearlessly and discover things easily...


Sat Mar 12, 2016 4:29 pm
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Post Re: Leadshine Dm series drives
i have been tempted to get a leadshine for experimenting. however i have a couple of cheaper stepper drivers i want to play with first. they are in the mail as well perhaps sitting on top of displacements for added weight. i am curious as to how you got your bench looking so much like mine lol


Sat Mar 12, 2016 8:21 pm
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Post Re: Leadshine Dm series drives
Hi Charlie. Perhaps a sign of a disordered mind?? Though I find stuff has an inertia of its own, no matter how hard I try, it just keeps creeping back... perhaps I will also take a picture of all the drives I have collected and tested over the years - it could fill a museum of stepper drives. I even have one that was reputedly used by NASA in the 80's, complete with matching nema 42 motor which is about 30cm long...


Sat Mar 12, 2016 11:14 pm
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Post Re: Leadshine Dm series drives
Hi Gerald just thought i would mention i had used a range of motors in my tests just to make sure it wasn't a motor issue rather than a driver one . It pays to cover all bases after all it could have just been a dodgy motor .
I did notice with the leashines the amperage been delivered to the motors was less than that given by the CWDs. Even with the DIP switches set at similar settings.
When i re test with the DCM i will make a note of actual amperage been devilved/drawn in each case . Must say again i have left the current set up with the CWDs all day and they dont get hot at all in half current mode and they get sightly warm in full current mode .
Micro stepping actual effects the amount of current thats drawn to . IT goes down as you micro step more yep i dont know way just noticed it does . Building a couple of these into new driver box http://www.ebay.co.uk/itm/DC-100V-10A-V ... SwKtlWj6Oo They are cheap and its a good way to montor the state of things . Also found this https://play.google.com/store/apps/deta ... eter&hl=en. You can turn your phone into a strobe tachometer prob not accurate for our use . Couldn't test my phone runs old Android version :(
As for manual question not off topic at all you just didn't bother answering in last thread . Think you have answered it in this one but still not sure :)
D1


Sun Mar 13, 2016 3:07 am
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Post Re: Leadshine Dm series drives
It sounds like the CDW may be delivering more current than it advertises unless it is just less efficient.

But also I have realised you are using the RMS current settings. I normally use the peak setting, which I find is quite adequate. In fact excess current can lead to higher resonance, and doesn't always equate to higher speed.

The highest current nema 17 I have is 1.7amp and many are in the sub 1.0 amp range. Obviously an advantage of the DM432C is you can set it to any fractional current setting you need. Hence you may need to use two types of drive for your rig...

I'd also consider closed loop stepper drives if performance is a real concern...

Re the current meter. Handy to tell you if the PSU is being stressed, but keep in mind a portion of the current is wasted in heat by the drive - so it does not give a direct indication of the current used by the motor.

Finally - do test with running equipment. The motors may be cool when mostly on standby, but run them flat out for a while and the temperature will rise...


Sun Mar 13, 2016 2:54 pm
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Post Re: Leadshine Dm series drives
PS - some more testing.

I don't have a lot of nema 23 motors to compare - most require more than 3 amps and I usually run them at higher voltage. But I did test the smallest motor, a half stack Pacsci motor, comparing the DM432C against the DM856, with both set to 3.2 amps and the same 35v PSU.

In this case - on a heavy duty pan tilt head running a 100:1 gearbox, the nema 23 achieved a panning speed of 90 degrees per second. With the DM856 at same settings it could reach 110 deg/sec.

I won't try and guess the reason, but it does seem that for nema 23 motors you may prefer a higher current drive than the 432c. It seems to work best with nema 17 motors.

That said I have occasionally apparently identical drives perform slightly differently. Looking at the serial printing on the case they can vary, and different versions are sometimes supplied from China vs other countries. So perhaps they are not all exactly equal?

In any case it is perfectly ok to mix and match. If you do appreciate the smoother operation of the DM series then I would use a DM556 or DM856 for the bigger motors - or else just use the CDW drives.

-off topic - but I noticed DMC16 only allows acceleration and velocity settings for jogging. In Mantis you can also set "jerk" which is a smoothing factor. It means jogging heavy axes like a boom arm can be better controlled with less shake. When setting point to point moves Mantis is also better since it is easier to see what velocity is really doing and what the maximum value is. Also, the acceleration curve is very valuable for checking the presence of shaky starts and stops. Perhaps in animation this is not so important, but still you like to run the move real time to check how it feels before shooting...

G


Sun Mar 13, 2016 10:00 pm
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Post Re: Leadshine Dm series drives
Hi Gerald think we are agreeing the Dm432c are better suited to Nema 17 . In my basic tests their was a noticeable drop of in top speed between 23 and 17s.
As for the CDW delivering more current than it should then surely that would lead to the motors getting hot . Which they definitely are not in any state running standing etc?
Been looking at your top pulse per sec figures before the motor stalls out is 103093.65 at 16 microstepping .The best i could get was 20000 so something def amiss.
These are my results again .
STEPPER MOTOR DRIVER SETTINGS
CDW556

NEMA 23
2 .1Amp 36 volt

800 steps per rev micro stepping max pulse per sec 12000 dragon
1600 steps per rev micro stepping max pulse per sec 20000 +dragon

NEMA 17 48mm
1.5 Amp 36 volt .Pulls .6 Amp half mode 1.5 Amp full mode at rest . Pulls 2.6 Amp running no load 3.5 Amp with load

800 steps per rev micro stepping max pulse per sec 19000 dragon
1600 steps per rev micro stepping max pulse per sec 20000+ dragon

LEADSHINE DM432C

NEMA 23
2.05 Amp 36 volt
800 steps per rev micro stepping max pulse per sec 2000 dragon
1600 steps per rev micro stepping max pulse per sec 5000 dragon
3200 steps per rev micro stepping max pulse per sec 11000 dragon


NEMA 17 48mm
1.39 Amp 36 volt
800 steps per rev micro stepping max pulse per sec 10000 dragon
1600 steps per rev micro stepping max pulse per sec 20000 dragon
3200 steps per rev micro stepping max pulse per sec 20000+ dragon

I wonder what everybody else is getting even with things like BEDs

Anyways DMC still not turned up ! And remember Gerald in this case the real time function is just to aid building the move it will all be shot stop frame. I appreciate Mantis will be better for proper real time stuff .
D1


Mon Mar 14, 2016 1:43 am
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Post Re: Leadshine Dm series drives
Thanks D1 - I did see the results previously and don't doubt them.

But it seems until you can also test with higher step pulse rates and nice acceleration curves it's all a bit academic... (I think you are still using an Arduino?) Not to mention with motors actually doing the work they are destined for...?

Meantime you might try running the 23's with the 432 current increased a little? I would suspect that the 432 current is actually lower than what it says, so that might make the difference. In fact your ammeter seems to support this theory even if it's just an indication...

Re building the move - I don't think you can underestimate the time that is saved if you can have instant replay of any changes you make.... otherwise why bother with the DMC?

[Edit]

BTW - Mantis would not have taken that long to arrive..! But maybe UK customs are more AUS friendly?

:)


Mon Mar 14, 2016 2:00 am
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Post Re: Leadshine Dm series drives
PS - Some final notes on squeezing more out of a DM432C which might also apply to other DM series drives.

The nema 17 motor which I tested was actually a Schneider or "IMS" motor. I used the mid-length version which is rated at 1.5 amp and is 47mm long. Note these are the same motors as used in some MRMC motion control heads - with an integrated drive.

http://motion.schneider-electric.com/pr ... ema17.html

Another generic motor I tested wouldn't perform nearly as well. So results will definitely vary according to the motor.

In a final test I was able to reach 5,000rpm with this motor with a pulse frequency of 133,333 hz and 8x microstepping..

To do this I upped the rated current from 1.5 amp to 1.8amp (peak), but more importantly reduced the P and I gain in the Leadshine software. I found the auto gain setting was too harsh and created resonance at high speed, which caused it to stall.

I basically halved both settings from ( P = 6,000 and I = 63 ) to > ( P = 3,000 I = 30 ) Nothing scientific about it - just what seemed to work...

The effect of reducing these gains was to smooth the motor vibrations generally. I believe the software auto tuning optimises the gains for very quick acceleration at low rpm, which is not what we need for moving a camera smoothly.

When running at high rpm there is not much torque so the motor can be easily stalled if disturbed during its travel. Hence achieving high speed requires a mechanical drive which has low friction and is well balanced. Note that if the motor is held in your hand or sitting loosely on the desk it can also stall more easily. So testing should be carried out in situ...

In practice this kind of crazy speed is not expected from a stepper motor and you would more often gear the drive to take advantage of the higher torque available at lower rpm. But it is interesting to see what is possible....


Mon Mar 14, 2016 8:59 pm
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Post Re: Leadshine Dm series drives
Hi Gerald i to noticed the motor stalls when sitting loosely. Couldn't work out why so didn't mention it but glad you have a theory. Trixy little things these steppers !
DMC still not turned up :( I hate ordering stuff from states never goes well .
D1


Tue Mar 15, 2016 1:12 am
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Post Re: Leadshine Dm series drives
Indeed - I found out by accident that solidly mounting the motor is important - it's not just for safety as implied by the manuals...

We must live in a relatively good space here. Shipping from the USA, Asia and UK is fast and under $1k = no customs. :)

The only problem is there is much less actual work... :(


Tue Mar 15, 2016 2:48 am
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Post Re: Leadshine Dm series drives
hi all,
I still use the TMC2100 driver. but have a look at the new TMC2130, nice features..



Thu Mar 17, 2016 11:50 am
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Post Re: Leadshine Dm series drives
It looks interesting. Perhaps one day someone will package it in a robust industrial format which is ready to use?

Recently I have also heard of another Chinese brand "YACO" which have a good reputation, though harder to find...


Thu Mar 17, 2016 10:28 pm
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Post Re: Leadshine Dm series drives
(..) the "standalone"-configuration(..)
(..) a TMC 2130-stepstick prototype withing the next days(..)

https://ultimaker.com/en/community/1749 ... er-tmc2130

####

very nice, I like the YACO drivers AC 110 - 220V - good for highspeed??
http://www.yankong.com/EN/product-c5.html


Fri Mar 18, 2016 12:08 am
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Post Re: Leadshine Dm series drives
Found this site the other day, the AZ series mechanical closed loop steppers looked interesting as well the information on the site itself.
http://www.orientalmotor.com/products/stepper-motors/dc-input-stepper-motor-driver-systems.html

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Fri Mar 18, 2016 1:54 am
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Post Re: Leadshine Dm series drives
MikeA wrote:
Found this site the other day, the AZ series mechanical closed loop steppers looked interesting as well the information on the site itself.
http://www.orientalmotor.com/products/stepper-motors/dc-input-stepper-motor-driver-systems.html

Hi Mike ya been digging again good find . Like those closed loop steppers they have the advantage over the leadshine variants in that they are absolute . They even have i nice little home button :D Seems perfect for rig applications to far down the path with current rig but next time maybe.
Hi Krupp not seen those drivers either nice small package may get on to play with . Just wondering if all drivers act like the cool step mode . The CWD i am using certainly alter the amperage the more load you apply so i assumed that was standard . Not really looked at the leadshines in that way .
D1
Ps DMC may turn up today yeah ! customs had it for 12 days boo :(


Fri Mar 18, 2016 2:59 am
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Post Re: Leadshine Dm series drives
hi D1, only know the tmc2100. good for VERY slow speeds. and with 46V very fast - up to 2m/s with the s-ramp. (dolly with 340g camera)..

but I think, with the new tmc2130 (coolstep / stallguard2) you can zero the stepper just by hitting the end of the track. but I´m not shure ;-)


Fri Mar 18, 2016 6:36 am
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Post Re: Leadshine Dm series drives
Mike - Oriental Motors (AKA Vexta) have always been recognised as one of the most decent manufacturers for steppers and motors, they have some nice technology and not to mention gear-reducers. But they are at the upper end of the price range. For example the nearest equivalent to DM856 is the RBK series, advertised as starting from USD $280. Still it seems tempting...

Krupp. YAKO have parallel models with Leadshine including closed loop and high voltage models.
The YAKO's seem like a bit better build and have a good reputation with industrial CNC manufacturers. Also more expensive than Leadshine, though not a lot more...

Re the TMC's - until they are packaged in a user friendly form, they are not practical for most of us. Setting them up seems too complicated, and they only work with small motors. For an OEM or a keen enthusiast (genius?) who is prepared to do the R&D to integrate them into a product, they seem a good option.

Over the years I have used a lot of Leadshines, and found them quite reliable and easy to use. (other than the odd one that wasn't quite right at the start...) In general I really can't complain...


Fri Mar 18, 2016 9:14 pm
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Post Re: Leadshine Dm series drives
hi gerald,

yes, motion control is a complicated subject - so I am very impressed by your 400W Slider Test:
http://vimeo.com/155938110

and your crane rig in action:
http://vimeo.com/138943976

..and the result!


Sat Mar 19, 2016 12:27 am
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Post Re: Leadshine Dm series drives
Hi Mike had a closer look at those closed loop steppers . Unfortunately the choice of motor size is very limited i don't think it would be possible to build a decent sized PT head using them . Shame and as Gerald as pointed out their not cheap think i will stick to my bit of plastic and optical sensor :D .
As for drivers i think we all have our favorites and that fines. If they do what you want then to do then stick with what ya know but it always nice when people share their opinions and experience .
Hi Gerald if ya still out their i have been adding up the amount of motor channels my crane and model mover need . Its getting a bit excessive the crane alone uses 7 channels .
Then we have my model mover because of the gimbal arrangement that's another 3 . Its them mounted on a revolve and track another 2 .
You can prob see were i am going with this that's a total of 12 can Mantis be made to run that many channels ? I know its a lot and prob more than most people need but i really want to use crane and model mover together . Its me big interest at mo and not many non pro rigs out their that do it so may get me a bit more work . Which would be nice as theirs not as much as their used to be in the old model making :(
D1


Sat Mar 19, 2016 1:53 am
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Post Re: Leadshine Dm series drives
Thanks Krup. I'm glad you appreciate the rigs. Shooting outdoor real-time can be a challenge and the motors are certainly a lot bigger than what you are used to... :)

D1 - If I ran out of channels I would separate the rig from the model mover, ie. run each on a separate instance of Mantis. In practice I've not had to do this, but it is possible to sync two Mantis units. In a stretch, I also have a DOS based Kuper system which can expand to 32 channels...


Sat Mar 19, 2016 4:45 pm
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Post Re: Leadshine Dm series drives
geraldft wrote:
Thanks Krup. I'm glad you appreciate the rigs. Shooting outdoor real-time can be a challenge and the motors are certainly a lot bigger than what you are used to... :)

D1 - If I ran out of channels I would separate the rig from the model mover, ie. run each on a separate instance of Mantis. In practice I've not had to do this, but it is possible to sync two Mantis units. In a stretch, I also have a DOS based Kuper system which can expand to 32 channels...


Cheers Gerald good to know


Sun Mar 20, 2016 2:52 am
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Post Re: Leadshine Dm series drives
PS - Mantis could potentially be expanded to 12 channels, but it would cost to do it as it would require custom changes to the Kmotion hardware device - unfortunately it's not a software thing... - so only worth while if a big order required it... :)


Sun Mar 20, 2016 7:19 pm
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Post Re: Leadshine Dm series drives
Maybe a useful link for anyone wanting tutorial / general stepper motor information: http://homepage.cs.uiowa.edu/~jones/step/

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Mon May 02, 2016 1:56 am
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Post Re: Leadshine Dm series drives
Hi Mike

I'd also point to the Geckodrive website for good in depth info on power supplies.

D1 - there are closed loop steppers in Nema 17 size. But note closed loop in either steppers or servos does not mean you should get rid of your opto homing gadget unless perhaps the motor encoder also has an index. While they can to offer more secure positional consistency generally and less resonance, they can still stall and lose position - and must be reset on those occasions the same as you would with a stepper.

G


Tue May 03, 2016 11:43 pm
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Post Re: Leadshine Dm series drives
geraldft wrote:
Hi Mike

I'd also point to the Geckodrive website for good in depth info on power supplies.

D1 - there are closed loop steppers in Nema 17 size. But note closed loop in either steppers or servos does not mean you should get rid of your opto homing gadget unless perhaps the motor encoder also has an index. While they can to offer more secure positional consistency generally and less resonance, they can still stall and lose position - and must be reset on those occasions the same as you would with a stepper.

G

Hi, Gerald, Gecko website is usually my first port of call along with http://www.galilmotioncontrol.com/ although you need to register to get the best out of it., as you say Gecko site has good in depth articles.
Came across the one above and thought I would add to thread and at the same time bring the thread back into

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Wed May 04, 2016 1:33 am
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Post Re: Leadshine Dm series drives
Hi Gerald think given up on closed loop steppers as you say if they not absolute theirs not much to be gained rig wise . Can see why servos are sometimes a better option the encoder on them must offer more opportunities.
Still haven't fitted the opto gizmo to a rig yet . Its fine for the large crane axis but i just cant fit it into a PT head without making things BIG ! So if i cant do all the axis their isn't much point . I have explained the problem to the fella for the new crane so a least he his aware of the limitations . Wish their was a easy solution theirs a lot of three day shots these days ( animation that is }
D1


Wed May 04, 2016 11:44 am
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Post Re: Leadshine Dm series drives
Well - like I said. At minimum make sure there is somewhere to mark a home position on the motor shaft. With overnights you are more likely to have issues with sets moving anyway...


Wed May 04, 2016 3:20 pm
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Post Re: Leadshine Dm series drives
You mean I got that right without knowing? From the start I have been marking the home point or zero point with a line or a notch of some kind. Did I miss a post, what is this "opto thingy"?


Thu May 05, 2016 6:09 am
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Post Re: Leadshine Dm series drives
Yep. That's a fancy way of doing what you already do.. :)

D1 made a disk with a hole in it and an opto detector to help find the index mark.


Thu May 05, 2016 11:39 pm
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Post Re: Leadshine Dm series drives
geraldft wrote:
Well - like I said. At minimum make sure there is somewhere to mark a home position on the motor shaft. With overnights you are more likely to have issues with sets moving anyway...

Hey i am a set builder my sets dont move ! :)
Think i mentioned before its a issue with the people i work with . So it would be good to solve in a cost effective manner . Gerald you are lucky to have a more easy going crew than me .
Hi Doug the opto thing is buried in the mega thread viewtopic.php?f=24&t=11275&start=600 page 16 its cheap and accurate .003 degree of drift if i remember correctly. But it required a 80mm disce fine for crane track etc but bit of a pain for PT Head .
New head i have built does have registration marks on motors but i cant imagine it will offer that .003 deg accuracy .
D1


Fri May 06, 2016 12:07 am
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Post Re: Leadshine Dm series drives
What do you mean easy going? I am the crew... well mostly :)


Fri May 06, 2016 2:24 am
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Post Re: Leadshine Dm series drives
geraldft wrote:
What do you mean easy going? I am the crew... well mostly :)


Ah their you go its hard to fall out with yourself but i do manage it occasionally :D
This is the compromise so far it requires a torch and a keen eye but a least it gives you a fighting chance .

[flickr]Image2016-05-06 11.30.16 by D 1, on Flickr[/flickr]
D1


Fri May 06, 2016 2:39 am
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Post Re: Leadshine Dm series drives
DISPLACEMENT 1 wrote:
geraldft wrote:
What do you mean easy going? I am the crew... well mostly :)


Ah their you go its hard to fall out with yourself but i do manage it occasionally :D
This is the compromise so far it requires a torch and a keen eye but a least it gives you a fighting chance .
D1

With a little imagination you could maybe adapt this principle, "one motor rev" to move output a specific distance for stop motion. Turning motor off would not affect the next move as it would require up to one revolution of movement to move the output.
http://507movements.com/mm_068.html

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Mon May 09, 2016 7:24 am
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Post Re: Leadshine Dm series drives
Hi Mike trying to get my head round that one . All i can think is its turning a 200 step stepper motor into a single step motor ? It would also add backlash to the system because theirs free play until the single tooth engages .
I may have misunderstood the concept but it also seems to add another layer of mechanics which is not good for me .
I may go back and test the optical thing and see how small a disc i can get away with . If i can get it down to the same size as a Nema 17 it may be a goer .
Ps so your post on that slider at Nab . A work of art on the machining front but looks very old fashioned .
D1


Mon May 09, 2016 12:41 pm
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Post Re: Leadshine Dm series drives
Hi, D1 my thoughts on this were using it on a dolly, the driven gear would have enough friction to keep it stationary (when level). The driven gear would move the dolly a fixed amount every rev. then be in "free wheel" until the next contact with the driver. If the motor/ drive gear is stopped when there is no contact with driven gear the slight occilation of the motor when stopped / powered down would not affect the position of the dolly, likewise when started.
Does that make any sense.

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Wed May 11, 2016 12:22 am
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