Porper Lathe

[Michael Webb]

Personally I think $400 for ball screw system is very cheap. I have a other lathes and cnc with ball screw and would choose that over cheaper system every time. Just my preference.

Another safety feature would be turn off the thread at either end of the feed screw so that there's no danger of automatic feed running into headstock or tailstock. I was surprised to find nothing built in to prevent this.

The feed screw motor doesn't have a lot of torque behind it so if it does run it's course to the head stock side, it will just stop, On the tail stock side, the secondary brass gear holder which is on the right side of the table, is my design and it should have a spring in place there. The spring set up will allow it to just slip, No damage there. Joe and Don have made a few other changes to the overall machine, I lost track years ago.
Hope this helps.

 

[Agent17]

The feed screw motor doesn't have a lot of torque behind it so if it does run it's course to the head stock side, it will just stop, On the tail stock side, the secondary brass gear holder which is on the right side of the table, is my design and it should have a spring in place there. The spring set up will allow it to just slip, No damage there. Joe and Don have made a few other changes to the overall machine, I lost track years ago.
Hope this helps.

I do not plan running the carriage into the headstock but I prefer this scenario than the one where the brass gear shreds :grin:

But is that 100% correct? Would have been nice to have some documentation with machine that explains this.

Your design? Did you have any more involvement or just help out on that particular feature?

Do you also know if that feed screw should run relatively straight because mine has a pretty big wobble so appears to have been quite bent when fitted? I can't see that being good for stability or long term wear issues.

 

[ratcues]

I do not plan running the carriage into the headstock but I prefer this scenario than the one where the brass gear shreds :grin:

The brass gear shredding is a worse case scenario. As Mike said, the carriage will stop and the load the motor and/or smoke the belt. Point being, if it gets to any of these instances, you are doing something really wrong.

 

[Agent17]

Point being, if it gets to any of these instances, you are doing something really wrong.

Of course, with all due respect, I am not a novice with regards cue making and lathes in general.

Just that this particular machine is new to me, and I'm looking for the things that i know can happen/go wrong.

If the torque of the motor 'gives up' before the the gears shred then that's a good enough feature for me.

As I said before, it would have been nice to have received some documentation that maybe explained all this.

I like your insert for the headstock, I'll be making myself something similar as soon as I've found a place in my workshop to actually fit the Porper.

Btw, does your feed screw wobble a lot? I don't expect perfection over that length but mine seems a little more bent than it needs to be.

Cheers

 

[ratcues]

Btw, does your feed screw wobble a lot? I don't expect perfection over that length but mine seems a little more bent than it needs to be.

I little. That's due to the way the actual screw is made. I talked with Joe about this a couple of years ago and he said it isn't a problem. The carriage/brass gear should work fine. If not, let me know.

 

[Michael Webb]

I do not plan running the carriage into the headstock but I prefer this scenario than the one where the brass gear shreds :grin:

But is that 100% correct? Would have been nice to have some documentation with machine that explains this.

You are correct.

Your design? Did you have any more involvement or just help out on that particular feature?

When I first got mine, the idler set up on the right side to level the brass gear was a square brass block with just a hole in it, the feed screw would actually start to cut threads in the block and bind the table. So I showed it to a friend of mine and we came up with the idler arm and spring for the secondary gear. I won't get into details but that was the last modification I gave him. We sought of lost touch over the years. U]

Do you also know if that feed screw should run relatively straight because mine has a pretty big wobble so appears to have been quite bent when fitted? I can't see that being good for stability or long term wear issues.

It is possible that your feed screw could be bent, The design of the brass gear set up on the drive side is a floating gear that will allow for movement without affecting the table to much.

 

[Michael Webb]

duplicated