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Author Topic: Machanical Automatic Tool Changer  (Read 23699 times)

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Offline Hood

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Re: Machanical Automatic Tool Changer
« Reply #90 on: February 07, 2014, 02:57:11 PM »
It all depends on the motor and drive but usually the rated is the max although I have Berger Lahrs on the Chirons axes and their rated is 4000rpm and Max is 6000rpm.

The 5.5Kw may be too low on torque if you gear   to get 6000rpm, suppose it depends on what you are doing.
You can usually pick up the low voltage DSD drives on eBay and they can be used with motors other than Allen Bradley as you can make up custom motor profiles. The only things you need are a suitable encoder on the motor and to know the motors specs.
Hood
Re: Machanical Automatic Tool Changer
« Reply #91 on: February 07, 2014, 03:04:03 PM »
My motor is only rated at 3.5kW so I would expect it to be close enough...

Those DSD drives are for servos right?  Or could I potentially use one with my existing motor?  I did notice that Fanuc literature is hard to find so just replacing what I have sounds more and more appealing, since I will no doubt have to set parameters and fix issues down the road.

I will look on eBay some more for a whole new motor/drive unit that is comparable as well.  When looking for a motor I obviously need to match RPM and output, but for the IP/A+ENC what additional featureds should I be looking for?  It can be open loop, but needs a differential encoder for the ENC, 0-10v speed control, anything else I'm missing?

Offline Hood

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Re: Machanical Automatic Tool Changer
« Reply #92 on: February 07, 2014, 03:34:14 PM »
Ah ok I was thinking it was 5.5 for some reason.

Yes the DSD's are for servos.

AC servos can be problematic as quite often you are tied to specific motors with specific drives. The Allen Bradly DDM and DSD drives however are quite versatile, the DSD's more so that the DDM's. You can, as I said earlier, set up a custom motor profile in them and as long as your encoder has hall signals as well as the normal 5v square wave they will be fine. The DSD can actually use encoders without Halls but each time you power the drive it will do a self sense and rotate about 1/4 turn. For an axis that could be problematic but for a spindle it would likely be ok.
 If you find something on eBay give me a mail first with the details as I will hopefully be able to tell you whether the motors/drive combo will be compatable.

For the IP-A controller you will want a drive that can accept +/- 10v control signals, most AC servos can do that but there are a few out there that are only Step/Dir. The Allen Bradleys however can do both analogue and position control.

Hood
Re: Machanical Automatic Tool Changer
« Reply #93 on: February 09, 2014, 08:14:20 PM »
I'm waiting to hear back about the 230v Allen Bradley motors, but if it comes to the point of buying a new spindle servo I think that the GSK ZJY208 3.7 or 5.5 motors will probably be the route I take. They take analog signals, and have tge speed and power I need, and since they have closed loop control I know they should work with the CSMIO ENC module.

Offline Hood

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Re: Machanical Automatic Tool Changer
« Reply #94 on: February 10, 2014, 02:51:05 AM »
The GSK as with any other servo drive in speed or torque mode wont actually close the loop, or at least not fully, the position loop is closed within the CSMIO however so not a problem, was just trying to make that clear :)

Hood
Re: Machanical Automatic Tool Changer
« Reply #95 on: February 10, 2014, 12:00:16 PM »
Right, I meant that since the driver itself can make the loop it should be able to do the same vi the ENC module.

I did talk to CS-Labs about what I need though and they gave me a diagram for AC induction vs AC servo spindle control that showed encoder feedback going to both the ENC and the driver, I thought (like you just mentioned) that the feedback just goes to the ENC module, but according to this the loop goes to both?  Or does one control speed and the other is position?

In any case those motors should do the job right?  The 3.7kw specs are right on with my existing motor, and bumping up to the 5.5kW isn't much more money, so maybe I could turn this from a drill and tap machine to a more capable mill.
Re: Machanical Automatic Tool Changer
« Reply #96 on: February 10, 2014, 12:06:25 PM »
Meant to have this attached:

Offline Hood

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Re: Machanical Automatic Tool Changer
« Reply #97 on: February 10, 2014, 01:31:24 PM »
If you are using a servo for the spindle with the CSMIO/IP-A you need to feed the encoder back to the IP-A so that it can close the loop to the spindle. In addition you also need to have feedback going to the Enc module if you want rigid tapping. You can do that with a separate encoder as in the diagram or you can also just feed the encoder to both the IP-A and the Enc. That is the way I have it on the Chiron and it works fine. Only thing that may be an issue is if you  have the spindle geared, in that case it may be required that you have a separate encoder for the spindle, I will find that out soon as I have plans to increase my spindle speed from 3800rpm to 8500rpm using a belt and pulleys, just need time to get it done and doesnt seem to be much of that for me at the moment :D

Hood
Re: Machanical Automatic Tool Changer
« Reply #98 on: February 10, 2014, 05:40:18 PM »
My spindle is belt driven, but I am not sure that there is actually any gear reduction, I will have to check.  Would it be better/would it matter where the integrated encoder feedback goes, vs the second encoder?  I should be able to buy whatever kind of encoder I need off of McMaster-Carr or some industrial supply store right?

Offline Hood

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Re: Machanical Automatic Tool Changer
« Reply #99 on: February 10, 2014, 05:43:59 PM »
You will need one encoder feedback going to the CSMIO and the other going to the Enc module. As said you can likely just do as I have done and feed both with the same encoder signals.
Hood