Electronic lead screw ELS - Rocketronics solution on Modern Tool C0636 lathe

[Janger]

Christmas at John’s house.

 

[PeterT]

Cant wait to see it functioning. Take lots of pics along the way.

 

[Janger]

I’m making the round stand offs to separate the two plates above. Naively just drilling straight through resulted in crooked holes. See pic. So I rigged up the er32 collet block and drilled half way with a 1/4EM instead. Then flipped and did other end. It’s much better. It is 11x deep the bore diameter so kinda deep but not crazy. It’s a bit of pain as I end up pecking a lot. How do people do this productively?

 

[Janger]

The control powers up normally.

 

[Janger]

Standoffs again. Mr John Nielsen @johnnielsen suggested I gun drill (is that what this is called?) the standoffs with a lot of pecks and lots of oil. Well I made one standoff now and at the far end of 2.1" drilling the hole is 0.005" out or shifted crooked to the side of the part. That seems pretty good to me. I ran the drill at 800rpm with no load clock wise to match the 800 rpm on the lathe which is going counter clockwise of course.

I bought a pedal foot switch to run the drill and you can see I've got the plastic 3d printed wing nuts going on the drill hose clamp to set the drill speed.

Thanks @johnnielsen that made a very straight and true hole. 3 more to go...

 

[RobinHood]

Maybe a carbide drill bit? Should be stiffer than HSS and, if the cutting edges are sharpened precisely, should drill a straight hole. HSS with good and equal edge geometry should work.

But gun drill is certainly the best way to produce deep holes as @johnnielsen advises.

In your situation, a drill & bore operation might be tricky because of the hole dimensions...

Good solution in the end with lathe & drill motor.

 

[PeterT]

With a length of 2.1" I would have held it in a collet chuck for concentricity, drill one side a bit more than half through, flip & drill the other to connect. Common issues for drifting drill
- drill not centered (TS off or collet block off in mill mode)
- drill edge geometry unequal causing pull/drift (use a fresh drill or anyways equally sharpened lands)
- too long a drill (use a stubby which is more rigid) & (drill half way on either side as mentioned)
- use a spotting drill with included angle >= drill angle (example 120-deg spot for 118-deg drill). Not a 60-deg countersink type drill like our shop teacher taught us
- oil & pecking & chip removal is always a good strategy
- if push comes to shove & you use EM, or carbide EM for even more stiffness, you still have to be aware of tip geometry. Sometimes its still better to drill undersize pilot hole even if it is off, but the EM cutting is not getting bogged down in the center. They are intended for plunging but not really drilling or deep drilling. They don't have any taper & you may run out of cutting edge vs depth. Carbide is hard & may tend to slip in chuck jaws but that's a side issue.
Anyway you got-r-done

 

[Janger]

Motor mount try 1. Now I need to attach it to the lathe. And I see there is a problem the motor shaft is too long. Did I misread the 3D model from the vendor or is it different?

 

[Janger]

Motor mount model tweaks...

 

[Janger]

Hi @gerritv on your install did you keep use of the hand wheels for manual ops? For the Z axis (back/forth on spindle axis direction) I can just disconnect the thread / leadscrew engagement and then use the handles. But for the cross slide the motor will always be engaged. Did you do anything different to prevent the motor from sending back current into the rocketronics control? like installing a switch to disengage the motor?

Another possible problem I don't see in the manual yet - what about the lathe turning the lead screw and the rocketronics trying to do the same thing at the same time?

 

[Susquatch]

Another possible problem I don't see in the manual yet - what about the lathe turning the lead screw and the rocketronics trying to do the same thing at the same time?

I would think you either remove the drive gear from the lathe or you disengage the feed lever. No way they can both be used at the same time without breaking something.

 

[gerritv]

The control has Z Off and X Off buttons to disable each axis motor. I manually use the X axis once motor is off. (aso saves heating from the motor drivers). Detent every 1.8° due to stepper of course.

To avoid risk of lathe driving my leadscrew I removed most of the gear train. There must be a key gear that you can remove on your lathe?

 

[Janger]

@gerritv thanks for the pictures. I like your magswitch mounted encoder.

 

[gerritv]

And the encoder pulleys are 3d printed

 

[Janger]

I made the lead screw to drive shaft adapter today. Used the tool post mounted drill fixture. Smaller than I expected little thing. #6 screws because I don’t have any M3 in house. Or wait maybe I do….

 

[Janger]

Better! M3. Now I have to drill the matching bolt pattern into the lead screw. Should I be concerned? I don’t think it’s hardened or anything.

 

[Janger]

Dry fit of the motor … it does stick out….

 

[TorontoBuilder]

Mine was shipped in 2 boxes but he forgot to tell me the tracking # for the second one.

Is your rocketronics system installed yet?

 

[TorontoBuilder]

Say @Janger if your set-up is powerful enough to drive the modern 1440 I expect that it can drive the lead screw of a Colchester Master 2500. May I ask what motor options you went with?

 

[gerritv]

Is your rocketronics system installed yet?

yes, been using it for a few months on a 10x22 lathe. Very pleased. Let me know what you want demo'd for your upcoming visit so I can get it set up ahead of time