Are these stepper or servo?

[Jackal66]

Hello,
The owner of our shop found out I was looking for a CNC mill. He showed me this one that was in his warehouse. It is an old NC with tape reader, Wells Index, 800 series. Are these stepper or servos? I am not familiar enough to tell the difference. He said they tried to wire it up a few years ago, and it smoked every board in it, and filled the shop with smoke.

The iron seems real good and no slop in the ball screws. A 3hp motor.
He will probably let me have it for around $700 and throwin a horizontal/vertical motor powered indexing head that came with it.

Let me know any info you can give about it.

Thanks in advance,

JAckal

[Al_The_Man]

Something of that vintage would be brushed motors if servo's, but there is no sign of brush caps, unless they are inside the end cover.
Al.

[Jackal66]

Thanks AL,
I can't make out the tag on the motors without removing the motors. They are an EC? brand, I think, and the info says permanent magnet.

Also at the end of the motors are a spring loaded scissor looking contraption, with a small button in the middle. It appears to be a coupling, or maybe a tachometer with misalignment springs?

Here is a sketch of it IIRC.



Would these servos be worth re using on a retro on the mill? They were strong enough for the mill initially, when new. I just would like to get the mill running before sinking a lot into it. The mill seems tight and good condition, no wear, but if the bearings and the head are junk, I might have to sell it for extra parts and find something else.

Thanks,
JAckal

[Al_The_Man]

I am assuming these are on the rear of the motor as the drive end appears to be using timing belt or?
If on the rear, these would normally be attached to, and drive the encoder, if so this would indicate Brushed servo's.
Al.

[Jackal66]

That is it 100%, Al. Are these worth re-using? Would it be better to get something else. If I can get the good Gecko drives and a breakout board and get the machine running from a PC with Mach, then buy the bigger ( if needed) servos.

Al, let me know what you would do, if it was yours. I am going to run this in my home shop. Eventually I will be working out of my shop 40+ hrs. a week.

Thanks,
JAckal

P.S. Can you tell me how to hook up a set-up with a jumper so that I can jog the table around to check for binding and bearing noise?

[Al_The_Man]

If the motors are in good shape, brush length, armature condition, then I would re-use as I assume they must have run the machine OK in the past.
If the drives are still there with the power supply, you should be able to use a battery box to jog using the analogue input of the drive, otherwise you could use a large battery like and automotive type but you will not have speed control.
Al.

[metalcaster4jc]

Wells Index is still in business in Muskegon, MI. Rick the President would be able to tell you everything about the mill. And I know that you can still get parts for the mill, probably not the controller though. I bet that the controller is a sharnoa early vintage.

[metalcaster4jc]

BTW if you do decide to sell the mill, I would contact Rick at Wells Index. He buys back old Index mills and rebuilds them for resale. I bet you would get all your money back and then some. But it should be a good machine to retrofit.

[machinewbie]

Hi Jackal,
I have a modified Wells like the one you are looking at. The motors are DC servos. They are plenty strong for major hogging if desired. Mine is a hobby tool so I am not usually in that big of a hurry! The contraption you drew is the coupling between the end of the ballscrew and the encoder. The mill is very heavy. Wells castings are legendary. Mine has RUTEX driver cards, but I think Gecko now makes drivers capable of driving those motors and associated axis components. Mine is setup with DeskCNC for control. It is a nice package, but has no where near the user base or support that I see with MachIII.
Good luck!

[Jackal66]

Wow ! Thanks for the help and all of the good info, guys. I will try to get this machine if at all possible ( if he is reasonable). When it was sent in it had a 4th axis rotary table with it. The table is a big huge hulk.

The electrician that hooked it up said smoke filled up the shop as soon as it had power to it. Nothing inside the panels look black or burned, but there is a board missing out of a slot, and the retainer is off to one side. This may be the 4th axis board????

The owner thinks it is junk, but it has been sitting for 8 years. A welder that used to work there tried to rig up the rotary table for a circle burner for a torch. I want the rotary table, too.

If I get this I will bug a few of you for info.


Thanks a lot,

Now with a little more info to work with, a little higher price would be ok.

There are marks on the motors where they might have been rebuilt or taken apart.


JAckal

P.S. machinewbie,

Do you have any pics of your mill or controller ?

[metalcaster4jc]

This is the link for wells index http://www.wellsindex.com/.

[Jackal66]

Thanks Andrew,
I'll contact them.

JAckal