Reducing feed on a PM-1236 lathe

tertiaryjim said:
The gun drill will need high pressure coolant feed. I think it's around 1200 PSI.
Have you got a pump for that?
Another forum had a suggestion of using a power steering pump.
They should produce the pressure and volume needed.
Click to expand...

FWIW, 1200psi is nothing to play games with and pressures like that at close range will tear flesh in a nasty way. If you do obtain/use such a pump, caution and care are the theme of the day...


Ray
 
woodrowm said:
Thanks for your input, it looks as though I will be shifting gears tomorrow, by the way the suggested rpm is 700.

Thanks,
Sonny
Click to expand...

At 700 RPM, you won't have any problems spinning a 22 tooth against the large gear.

Ray
 
Just to let you know after the gear change (top 22t middle 127t and lower 52t) the best I could get was .018 feed rate, so if I have done my math right if I use top 24t middle 127t and 96t lower I should get somewhere between .001 and .0009 feed rate. Now to find or make a 96t gear.

Does anyone know if the gears in the PM1236 are standard or metric.

Now for the air pressure after talking with Doug (great guy, knows his stuff about gun drills) at Sterling Gun Drills you can run a spray mist system with shop air (they sell a unit just for this but out of my price range) for what I am doing.
So his suggestion was to get a Bijur Spray Mist System off of e-bay (which I did for $185 free shipping) and send it to him and he would make sure that it will be up to what I am doing.

Thanks,
Sonny
 
woodrowm said:
Just to let you know after the gear change (top 22t middle 127t and lower 52t) the best I could get was .018 feed rate, so if I have done my math right if I use top 24t middle 127t and 96t lower I should get somewhere between .001 and .0009 feed rate. Now to find or make a 96t gear.

Does anyone know if the gears in the PM1236 are standard or metric.

Now for the air pressure after talking with Doug (great guy, knows his stuff about gun drills) at Sterling Gun Drills you can run a spray mist system with shop air (they sell a unit just for this but out of my price range) for what I am doing.
So his suggestion was to get a Bijur Spray Mist System off of e-bay (which I did for $185 free shipping) and send it to him and he would make sure that it will be up to what I am doing.

Thanks,
Sonny
Click to expand...

Hmmm, don't know the specs on those gears and will try to get some info for you.

By any chance, did you try it with a 24/127/52 combination? Maybe I was seeing things wrong and that a larger gear at the upper position will get you in the desired ballpark... For sure though, you want a larger gear driving the bottom gearbox.

Ray
 
I found some extra gears for my Grizzly 16" lathe. I can double or halve the threads and feeds indicated on the QC box. That is good,since the QC box does not originally have the number of available threads I'd really like to have. It does now! Also,my lathe would only go 60 RPM as delivered,which is ridiculous for a machine that can swing 24" in the gap,or only for use over the ways. I made a 2 step pulley and halved the speed range. At least the lathe will do 30 RPM now.( I wish it would do 15 RPM.) Modern lathes are chronically made to run TOO FAST. I'm not too concerned about halving the high end speed. I have a Hardinge HLVH for small work.

I always have collected gears where I can,and it has paid off a few times. My Harrison milling machine has an old fashioned power feed that uses change gears to change the speed. I found out that old 6" Atlas lathe gears work just fine on it. It would be a major pain to remove the old power feed and modify the mill to accept a Servo power feed. Someone was offering to make gears for several hundred dollars for 2!! I'll use the Atlas ones!!(I could have made them anyway). Fortunately,I have a Bridgeport type mill with a Servo brand power feed on it. Also,I have a Deckel fp1,but have yet needed to use it. Just too used to my Bridgey,and have many attachments for it.

The message is,COLLECT gears. There are always gears for sale on ebay. Of course,you have to have the correct teeth.
 
OK, just spoke to Matt... No, he doesn't have specs on those gears about pitch, pressure angle etc. I'm not sure if they're 14's or 22's...
I'll be in the shop later today and see if I can measure things.


Ray
 
Good morning - That would be great any info would be helpful, by chance do you know if they are metric or standard I ask this because I need to make a 96t gear to get the feed that I need. If they are metric i need to get a #7 involute cuter if it is standard I would need a #1-1/2.

Thanks,
Sonny
 
Hi... Sorry for the slow reply.

OK, the circular pitch, as best I can measure, is 0.146" (3.71mm). Width of all the gears (not that it really matters) is 0.392" (9.96mm).

Ray
 
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