Beaver Knee mill conversion- by a newbie

Hello every one, I am about to convert my Beaver(yes, its a nice one and I hope I dont stuff it).
Just like to say I have done the usual months of reading posts and in the end I have thought bugger it I am gonna do it.

I got 2 AB servos at a sale but I dont know if they work and they dont have drivers so I bit the bullet and ordered from China.

I have ordered two 750w what servos after reading what Jazz and Dave were talking about on the Bridgeport conversion.

Now I am wondering which controller and whether to use Linuxcnc or mach. Looks like I am gonna spend some hours here.

Happy New Year to Everyone.

Hi, its a fun project for sure :)

If you have the funds, I would recommend the CSMIO range - top quality and more I/O than any build will need, I've added bells and whistles to my BP and still have spare I/O ;)

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Originally Posted by Davek0974

Hi, its a fun project for sure :)

If you have the funds, I would recommend the CSMIO range - top quality and more I/O than any build will need, I've added bells and whistles to my BP and still have spare I/O ;)

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Hey up Dave

Thanks for you advice.
It seems too expensive , but I have looked and looked again and I know your right, but i keep thinking the money I save will pay for a Z axis servo.

I was also looking at the Masso ,Cmsio and the chinese XHC MKX-IV axis.
But I am like a kid with a tanner in my palms and the old woman saying well choose some sweets but not the ones you want , only those you can afford.
Its looking like I will have to get another tanner and turn it into a bob(shilling, not break out board).

Its a tough decision is this one.

Servos came today. I paid for them on 28 December. That is amazing service. They were sent from china bought from fasttobuy on ebay.
Going to have to make up my mind on the controller soon.

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Originally Posted by ukmxer

Servos came today. I paid for them on 28 December. That is amazing service. They were sent from china bought from fasttobuy on ebay.
Going to have to make up my mind on the controller soon.

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Its the cables I believe that are expensive if you don't get the servo and driver with cables as one unit.

Hey up Clive, I have got the cables with the motors and controllers. The ones with a round plug on one end and D on the other.
Are those the ones you mean?

Just trying to understand the chinglish manual, it's not going to be easy(LOL).

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Originally Posted by ukmxer

Hey up Clive, I have got the cables with the motors and controllers. The ones with a round plug on one end and D on the other.
Are those the ones you mean?

Just trying to understand the chinglish manual, it's not going to be easy(LOL).

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Ah! In post #1 you said you have two AB servos without the drivers

Oh yes I have those two but I got no wiring or controllers with them, so they are on the shelf in the workshop.Attachment 23538 this is a picture of the label.

I bit the bullet and got the CSMIO/IP-M. Now it is time for my journey to begin.
I have no experience in machine building, so I look forward to learning something new.

Could someone please tell me if I put 2500 in as my encoder steps per or 10000(quad) in mach motor tuning.
This is from the manual for my servo :-
The encoder feedback 2500p/r,15 line increment model, differential output
I have it running step/dir through the csmio ip/m . The servo model 90ST-M02430.

will be 10,000 i think - they call it "all edges" so it senses 2500 rising edges plus 2500 falling edges and then the same again on the quadrature output so 10,000

I've never heard it called edges before, it's normally counts, and for quadrature encoders, it's always four times the slots/lines.

However I have seen various terms used, so if you're unsure, just try the lower figure. Worst case scenario, things only move a quarter what you expect.

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Originally Posted by ukmxer

Could someone please tell me if I put 2500 in as my encoder steps per or 10000(quad) in mach motor tuning.
This is from the manual for my servo :-
The encoder feedback 2500p/r,15 line increment model, differential output
I have it running step/dir through the csmio ip/m . The servo model 90ST-M02430.

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Well yes and no really. Yes your 2500ppr becomes 10,000ppr because it's quadrature encoder so 2500 x 4. But in motor tuning you need to divide 10,000 by the pitch of your ballscrew because your entering steps per MM or Inch into tuning.
So 10'000 pulses per rev which becomes your steps per revolution in mach3 is divided by say 5mm pitch becomes 2000 pulses per MM.

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Originally Posted by JAZZCNC

Well yes and no really. Yes your 2500ppr becomes 10,000ppr because it's quadrature encoder so 2500 x 4. But in motor tuning you need to divide 10,000 by the pitch of your ballscrew because your entering steps per MM or Inch into tuning.
So 10'000 pulses per rev which becomes your steps per revolution in mach3 is divided by say 5mm pitch becomes 2000 pulses per MM.

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Just a minor correction, 2500ppr becomes 10'000Cpr.
Although they're often mixed up anyway, pulse per rev generally refers to the number of pulses each channel produces per rev, which is usually the same as the number of lines, whereas the counts per rev refers to the total number of changes detectable by an encoder counter/reader, which in the case of quadrature encoder is four times the pulses/lines.

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Originally Posted by m_c

Just a minor correction, 2500ppr becomes 10'000Cpr.

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Yes noticed after posted didn't put counts but didn't think in this case needed correcting because I gave the figure OP needed.:whistle:

OK, thanks for your help, looks like I have some studying to do.

I have the X axis mounted and working. i set it up using the settings menu,set steps per unit. My mill has its own DRO, so I used that to help me config steps per.
Attachment 23736
Bit of a bodge, but I was not sure it would work, i will make new plates for the X and Y once i have it working.
The backlash is massive at the moment so I will have to adjust that, before I use the machine in anger.
Attachment 23737
I am installing a digital tachometer today. The Varispeed seems way off what it is supposed to be.

I have something wrong somewhere, It would occasionally do a small weird oscillation as if it was looking for its position and would then give an error on the drive.Other than that it was working great.

I have brought my Y axis motor back into the house, so I can play about with mach 3. Its cold in the workshop and a little damp at the moment. I am on with my Y axis motor mount, so time permitting I will have it running in the next two week.

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Originally Posted by ukmxer

I have something wrong somewhere, It would occasionally do a small weird oscillation as if it was looking for its position and would then give an error on the drive.Other than that it was working great.

I have brought my Y axis motor back into the house, so I can play about with mach 3. Its cold in the workshop and a little damp at the moment. I am on with my Y axis motor mount, so time permitting I will have it running in the next two week.

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The oscillation is because the drive is struggling to settle and find position the drive then faults because couldn't find position fast eneough. you'll need to play with Gain(PID) settings in the drive. But first I'd check your table is moving freely and the Jibs etc are not too tight.

Also you cannot set the PID settings or rather tune the motors on the bench. To do this correctly must be on the machine and working exactly as would in use. By that I mean with all guards, vise's etc permanently on machine while in use so can tune to weight your shifting.

Thanks for your help Jazzcnc.
The jib strips are worn and awkward to set. As soon as I have done the motor mounts the table is coming off so I can put oil feeder lines in, so I will do the jib strips then.

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Originally Posted by ukmxer

Thanks for your help Jazzcnc.
The jib strips are worn and awkward to set. As soon as I have done the motor mounts the table is coming off so I can put oil feeder lines in, so I will do the jib strips then.

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Yes often the case on old Iron. Many people try to tune there way out of sloppy machines but all there doing is stressing motors/drives when good strip down/clean and setup is all that's required.

Wouldn't mess around with any PID settings until you have done this and took as much backlash out as possible.

Just installed a tachometer. And it looks like the speeds were out.Attachment 23738

I forgot to say earlier , I used a piece of software called gearotic 3 to calculate the belt length from the pulley sizes and pitch centres.

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Originally Posted by ukmxer

Just installed a tachometer. And it looks like the speeds were out.Attachment 23738

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You'll probably find somebody has had it apart at some point, and not realigned the gauge correctly.

I put paint marker on the rack before I started and put it back on where it came off. So it was probably wrong to start with.
I was so giddy about the tach working I never thought about that.
Thanks for your help m_c. Looks like I will have to separate it again.
Come back in now to thaw out, and put my order in to huddersfield bearings for the Y axis belt and pulleys.