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Author Topic: 2 Axis Dispaly w Encoders  (Read 2979 times)

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Offline olf20

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2 Axis Dispaly w Encoders
« on: August 30, 2017, 06:03:25 PM »
I want to be able to identify various places on my mill
table for different projects. I don't want to connect in
any way.
I also do not want linear scales. I have dual shaft steppers
and I want to mount encoders on the x and y axis so I can
move the table to a exact location, then go about my machining.
Ebay has 2 and three axis digital readouts, but I"m not sure which
encoders would be the right ones. I have contacted one of the
suppliers but have not heard back from them.
http://www.ebay.com/itm/2-Axis-Digital-Readout-For-Milling-Lathe-Machine-With-Precision-Linear-Scale-Hot/252862032164?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D45729%26meid%3D21c7301be2ee4acaa337ff9a4f0bd02a%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D322514107578&_trksid=p2047675.c100005.m1851
Have any of you done this?
Care to share particulars.
olf20 / Bob
« Last Edit: August 30, 2017, 06:09:07 PM by olf20 »
Mach3, Atlas Knee Mill, 4th Axis, VcarvePro, ESS, Super PID.
Been Heating with corn since 1998
Re: 2 Axis Dispaly w Encoders
« Reply #1 on: August 31, 2017, 03:44:51 AM »
Hi,
that read out is made for a particular linear encoder. You will have to match the linear distance travelled per count to one count of your rotary encoder.

If for instance one linear scale count is 0.01mm then you will have to arrange a rotary encoder to match... lets say you have a 5mm pitch ballscrew
direct coupled to your stepper then the stepper will rotate (0.01/5)*360  which is .72 degree. Thus your one count is 0.72 degree or (360/0.72)= 500 count per rev,
therefore your rotary encoder must have 500/4=125 lines. I don't recall seeing an encoder with that unusual number of lines.

It may be some of the 'programmable' magnetic line encoders could offer the flexibility to specify some unusual number of lines. The only ones I've seen locally
have been worth BIG BUCKS, like $800 each!

To be honest I think trying to match a linear scale to a rotary encoder is going to be a real battle.

Perhaps ask the manufacturer of the readout if it is possible to 'reprogram' the readout , that I suspect would be a lot easier than the reverse.

Craig
My wife left with my best friend...
     and I miss him!

Offline olf20

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Re: 2 Axis Dispaly w Encoders
« Reply #2 on: August 31, 2017, 07:27:46 AM »
I have email the supplier, but have not heard back yet.
I see what you are saying about matching the encoder
to the display.
Thanks for your help!
olf20 / Bob
Mach3, Atlas Knee Mill, 4th Axis, VcarvePro, ESS, Super PID.
Been Heating with corn since 1998
Re: 2 Axis Dispaly w Encoders
« Reply #3 on: August 31, 2017, 05:59:50 PM »
Can you not just use Fixture Offsets G54--G59 0R G54.1?

Nick.

Offline olf20

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Re: 2 Axis Dispaly w Encoders
« Reply #4 on: September 01, 2017, 07:53:59 AM »
Yes I could, but I wanted something absolute
not connected to Mach. It's not a big problem
just something I was thinking about.

Manufacturer responded that their system
will not work with rotary encoders.

Thanks for the replies.
olf20 / Bob
Mach3, Atlas Knee Mill, 4th Axis, VcarvePro, ESS, Super PID.
Been Heating with corn since 1998
Re: 2 Axis Dispaly w Encoders
« Reply #5 on: September 01, 2017, 05:48:30 PM »
Hi Bob,
I think that it would work with a rotary encoder its just that rotating 'one click' on your encoder may mean you readout increases by .125mm say.
If the readout is to be useful then the actual distance travelled when your stepper rotates 'one click' has to be identical to the readouts increment for
'one click'.

You could certainly do it with an Arduino or similar. Are you electronically inclined? I thought about it last night and wondered whether an Arduino could
'translate' your rotary encoder to the same as the readout expected from its matching linear encoder. But then thought well if you are using an Arduino why
bother with the readout at all?

You can probably tell I have given this a little thought because I wanted a similar thing for my mill. My inclination at that time was to use linear differential
voltage transformers as the sense elements.  As my experience grew I cam to realise that while my Mach mill doesn't have encoders or LVDTs provided the steppers
don't lose steps, and they don't unless I crash it, then Mach IS THE SAME as the readout, ie I don't really need an independent system at all.

I soon found other ideas and projects to absorb me rather than pursuing this one down a rabbit hole.

Craig
My wife left with my best friend...
     and I miss him!

Offline olf20

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Re: 2 Axis Dispaly w Encoders
« Reply #6 on: September 02, 2017, 07:29:17 AM »
Thanks for the reply Joe. I just don't want to leave Mach on
all the time. This solves one problem, and the other is quick
reference to several setups when not using Mach.
Thanks for your reply.
The manufacture just email me back and said they do have
the rotary encoder for the display.
I might be in luck after all.
Thanks
olf20 / Bob
Mach3, Atlas Knee Mill, 4th Axis, VcarvePro, ESS, Super PID.
Been Heating with corn since 1998

Offline RICH

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Re: 2 Axis Dispaly w Encoders
« Reply #7 on: September 02, 2017, 08:43:30 AM »
Bob,

Let use know how things go as I may be interested.

RICH

Offline olf20

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Re: 2 Axis Dispaly w Encoders
« Reply #8 on: September 07, 2017, 08:06:45 AM »
Well I got a reply from the Supplier.
" sorry for the delay reply.
No problem, please see the attached picture, it's the rotary encoder for milling machine.
You don't need to reset the readout, the SDS6-2V can recognize the rotary encoder automatically
But your milling machine must have the place to fix the rotary encoder.
The price for the rotary encoder is US $146.
Should you need any further help, please feel free to let us know.
Best regards and have a nice day."
I'm investigating other encoders to find a cheaper one.
But at least we know something is out there.
Will post back when I find more.
olf20 / Bob
« Last Edit: September 07, 2017, 08:10:21 AM by olf20 »
Mach3, Atlas Knee Mill, 4th Axis, VcarvePro, ESS, Super PID.
Been Heating with corn since 1998
Re: 2 Axis Dispaly w Encoders
« Reply #9 on: September 07, 2017, 02:13:05 PM »
Hi,
I don't understand:
Quote
But your milling machine must have the place to fix the rotary encoder.

Attached? How? It is like some sort of quasi linear encoder?

Craig
My wife left with my best friend...
     and I miss him!