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Re: Encoder Basics

Posted: Tue Dec 01, 2020 10:42 am
by eng199
gttool wrote: Thu Nov 12, 2020 3:06 am Oak related
I have not been able to find any reference to using Absolute encoders in the forums .
looking at buying a pair of Delta A2 drives and servos for a lathe they are available with absolute encoders ?
Just waiting on a price back for them
Is there any plc programming changes to be made to use them ?
Thanks
The drives repeat position to the control in incremental form. The encoders will be incremental from the control's perspective. Absolute position retrieve from Delta is not supported on any current Centroid hardware.

Re: Encoder Basics

Posted: Wed May 05, 2021 1:57 pm
by martyscncgarage
Basic testing of a differential encoder on the bench by Polaraligned:

Re: Encoder Basics

Posted: Sun Oct 03, 2021 4:40 pm
by polaraligned
Soldering to a DB-9 Connector.

I had a gentleman send me his cables and encoders because he kept getting differential errors. Upon examination I was able to readily pull one of the encoder wires right out of the pin. The solder did not flow out and bond to the pin as seen in this picture. (white wire)
IMG_4825.JPG
A close up of the pin shows no adhered solder.
IMG_4843.JPG
When I removed cable by heating solder joints, there were a couple that did not show any bonding of the solder. See second pin from left.
IMG_4844.JPG

I will show some good suggestions on soldering to these connectors in the following pictures:

First, use a good electronics flux on the pins. Apply fairly heavily. Do NOT use a plumbing solder as it is acid based and too corrosive for electronics.
IMG_4838.JPG
Heat the pin and lay a small bead of solder in the cup of the pin.
IMG_4846.JPG
Strip your wire a little longer than you need and flux it up, especially if it is copper that is not tin plated.
IMG_4847.JPG
Now tin the wire by heating it and adding a very little bit of solder. You can then snip the ends to proper length and you have no worries about stray strands of wire.
IMG_4848.JPG
You can then just lay the wire right onto the pins that have a puddle of solder then apply the iron tip to the wire and it will sink right into the pin.
Not perfect in the picture below, but I was dealing with previously used connectors.
IMG_4850.JPG
IMG_4853.JPG
If you do this correctly you will absolutely not need any sleeving to go over these pins.
It is best to use 63/37 rosin core electronic solder as it is a eutectic solder, that is, it has no plastic region- in other words, it goes from liquid right to solid as it cools. That leaves less chance for a slight motion as the joint is cooling to cause a cold solder joint. I used 60/40 here, but I have been soldering for 45 years. I would not recommend any lead free solders for the inexperienced. Lead is your friend :D

EDIT: And never melt the solder on the soldering iron tip. Heat the metal and let the solder flow to the heat. Don't let the solder melt off the iron tip and into the joint or the solder connection will fail. Often I put a small spot of solder on the iron tip which helps with transferring the heat from the iron to the joint and does nothing more.

Re: Encoder Basics

Posted: Sun Oct 03, 2021 4:49 pm
by martyscncgarage
Ugh, that is clearly not the way to solder.
Thank you for taking the time to show what it should look like when properly done withe the CORRECT iron, tip, temperature and solder.

Marty

Re: Encoder Basics

Posted: Sun Jan 30, 2022 8:15 pm
by Degen
Yes Ug.

Leadfree is about using the correct leadfree solder. It can be as easy as lead. The main difference is it has a narrower but slightly high range. 729-735F so a proper temperature controlled iron is needed. As to best solder KOKI.

Re: Encoder Basics

Posted: Fri Jul 15, 2022 1:18 pm
by devin_decater
My bad - you're right, this should have been a new thread. It's been a LONG time since I've done any forum communication. Feel free to delete - I'm starting new thread now.

Re: Encoder Basics

Posted: Fri Jul 15, 2022 2:48 pm
by martyscncgarage
devin_decater wrote: Fri Jul 15, 2022 1:18 pm report.zipI’ve been working to get the fourth axis together on my antique M400 machine. It was working fine when I originally bought the machine (well used) in 2018, but I never had a job for it and blew up the servo drives (SD3 and SD1) in 2019.(I think my solar system was the culprit, I regularly see 257 volts, now I have everything transformed down) I had the drivers repaired and since then the fourth never worked correctly. To be fair I didn’t even try to hook up the fourth until over a year after I got the drives back. I believe I have narrowed the issue to the encoder, which might have been wiped out in the overload incident. When I run the “move sync” and turn the encoder the counts are correct, but the commutator counts like 1-2-7-7-6 I never see 5 and I guess it’s combining the 3 and 4…? I can’t find any real name brand or info on this encoder, it’s on the LeeDan 750W servo motor, which is driving a Centroid branded 5C fourth axis. I have gotten the servo working two or three times for a period of 5 min or so and end up with a “A axis commutator” error - unsurprising. I’ve tried cleaning the encoder disk using electronics cleaner (can make it worse at this point!) to no avail. I’m afraid the issue is electrical/electronic.

So long story to get to the question- is it possible to obtain a replacement encoder which will plug right in with the existing micro plug? Or even better is there a known company which can repair the encoder I have? The best solution to me would be to find a whole new servo, ideally a more modern unit which has better waterproofing and smaller pancake style form factor so this thing takes up less space on my crowded shelves when not in use! If I cannot get a plug and play encoder for the existing drive and I’ve got to figure the wiring out anyway I would prefer to have a much better servo as this LeeDan is kind of a POS to begin with and at the end of its life anyway.

4FBBBAC6-7195-4AE0-B97B-C6CDE458DDDA.jpeg

FF540E6F-B4AC-48D3-89A1-392C3AF304E0.jpeg

15EC3196-895C-4333-A6BA-01CDF6DBCD32.jpeg

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You should have started your own new thread...
Give Centroid a call...