Semco cnc mill problem

[Hood]

What model is the encoder?

 

[scottmk1]

What model is the encoder?

It's a Renco RHS15D-1000-1/4-5-CA4-VC-0-M1-S

Whats a breakout board? The top terminal block on that green device has more spaces than the lower one and appears to be filled with resin in the middle.

 

[Hood]

Ah ok, it may be a line driver then, are there double the wires coming out as going in?

You should be able to get an encoder for that easily enough as it just seems to be 1000 line 1/4" shaft size and 5v.

 

[scottmk1]

OK, I guess there are others that will fit, rather than having to get a direct Renco replacement?

I think there is double the amount coming out of it than going in. My question about the breakout board was genuine mind, I don't know what one of those is?

 

[Hood]

Yes, maybe even one of the HEDS style would fit.
You may not even need a 1000 line encoder as you should be able to set the parameters in the control to any resolution.

I would try and get hold of a scope and test the encoders output, it may even be the line driver that is knackered and the encoder fine.

Ok if there are double coming out then it does sound like it is a line driver, basically what it is doing is taking the single A, B and Z signals from the encoder and changing them to differential signals A+ A- B+ B- Z+ Z-.

A breakout board can be many things but in its simplest form is just a straight through connection board for easy connection of wires.

 

[scottmk1]

OK thanks for the explanation. Hopefully it is the line driver as there is a spare one in the control panel, just laying in there so maybe these things are prone to failing. I'll swap it tomorrow and see what happens.

 

[Hood]

Just make sure it is the same thing as if it is covered in resin and you can't see then there is a chance it may be something else.

Line drivers are easy to make yourself, well when I say make you just need a line driver chip and some vero board so you can connect things up.

I had a quick look and Zapp have one of the HEDs type but they are 1024 line rather than the 1000 of your encoder. Seem a bit pricey though, they certainly used to be a lot cheaper for them.

https://www.zappautomation.co.uk/hkt300635-301g-1024b-5l-1024-line-optical-encoder.html

 

[scottmk1]

OK, they look the same but I couldn't see any markings on them whatsoever, I'll have a better look tomorrow.

That encoder doesn't seem too bad compared to others I've seen online, might not be easily mounted though.

 

[Hood]

They are simple to mount assuming you can drill and tap a couple of holes. I have even seen people gluing them in place.

As said it is a 1024 line one that I linked to so make sure, if you do go for it, that you can alter the parameters to suit. I would be very surprised if you couldn't but best to check.

I just had a look and afraid I don't have anything here, gave the last couple of encoders to my friend for his lathe and mill spindles I think.

 

[Hood]

CNC Drives have this type, never used them but have heard they are decent and you could set it to your 1000 lines. Not sure how post from Hungary would be with the current situation but probably fine.

http://www.shop.cncdrive.com/index.php?productID=346

 

[scottmk1]

Well I can drill and tap no problem, I will check if I'm able to choose the resolution on the GSK controller.

 

[Hood]

RS are cheaper than Zapp but only seem to do 500 line ones. Should be good enough for a Z axis on a knee mill.

https://uk.rs-online.com/web/p/rotary-encoders/2056869/

 

[scottmk1]

RS are cheaper than Zapp but only seem to do 500 line ones. Should be good enough for a Z axis on a knee mill.

https://uk.rs-online.com/web/p/rotary-encoders/2056869/

Thanks once again, its a bed mill if that makes any difference? Probably not.

 

[Hood]

Well unless you are going to be doing a lot of 3D milling then probably not.
Obviously it would be best to stick with 1000 line seeing as that is what it already has but...

 

[scottmk1]

Right so I managed to separate the housing of that green device, here is the back of the board:

The spare one is identical so I swapped it and it's still the same. Will see about acquiring a scope to test the encoder.

 

[scottmk1]

And it looks like the X axis motor has had a new encoder fitted:

 

[Hood]

Almost certainly a line driver, a search for the part number on the middle component will tell you for sure.
Have you made sure there is power getting to the encoder? If so then a scope is definitely the best way to proceed.

 

[Hood]

Yes, definitely and it is a 2500 line (much more common nowadays) which shows the parameter must be capable of being set for the encoder count.

 

[graffian]

I needed to check an encoder output. I bought a cheapo usb logic analyser to do it.

 

[scottmk1]

Almost certainly a line driver, a search for the part number on the middle component will tell you for sure.
Have you made sure there is power getting to the encoder? If so then a scope is definitely the best way to proceed.

1V between red and black wires at the encoder.