Thread: metal lathe feed rate questions

Hi Peter,
There are likely some gears you can change, but people will need to know.
Whats sort of lathe?
What gearbox it has?
Pictures?

Stuart

Originally Posted by Stustoys

Hi Peter,
There are likely some gears you can change, but people will need to know.
Whats sort of lathe?
What gearbox it has?
Pictures?

Stuart

good day Stuart.
the lathe is a taiwanese made " Demco record TY-110 " I'm not so sure what kind of gear box it is .
will have to stick some pictures up if needed.
Cheers
Peter

Hi Peter,
It doesnt ring any bells with me and google cant find one.
If someone here will doesnt know of it we'll need some pictures.

Stuart

p.s. Its likely that the change gears are pretty standard, but with pictures we wont need to guess.

If the lathe came with spare change gears you might be able to interchange them to reduce your feed rate.

Is there a chart on your lathe showing how the gears should be set up to achieve the feeds available through the Quickchange Feed box.If there is are the gears set up correctly?

If they are set correctly according to the chart you would be able to reduce the Feedrate by changing the (stud) gear,this gear would be the 1st driven gear in the gear train at the end of the headstock,you would probably have the Stud then an idler of some size and then the Screw gear which is attached to the leadscrew/gearbox.The lesser number of teeth on the Stud gear the slower the Screw gear will rotate reducing your feed rate.

Unfortunately unless you do the calcs you want really no what the feed rate is,not a big problem but you need to remember to put all the gears back to there correct positions for screw cutting.

Originally Posted by pipeclay

If the lathe came with spare change gears you might be able to interchange them to reduce your feed rate.

Is there a chart on your lathe showing how the gears should be set up to achieve the feeds available through the Quickchange Feed box.If there is are the gears set up correctly?

If they are set correctly according to the chart you would be able to reduce the Feedrate by changing the (stud) gear,this gear would be the 1st driven gear in the gear train at the end of the headstock,you would probably have the Stud then an idler of some size and then the Screw gear which is attached to the leadscrew/gearbox.The lesser number of teeth on the Stud gear the slower the Screw gear will rotate reducing your feed rate.

Unfortunately unless you do the calcs you want really no what the feed rate is,not a big problem but you need to remember to put all the gears back to there correct positions for screw cutting.

Thanks .
here is some pictures of it. I sure I got the setting right . the E and number 2 is the lowest setting I presume .
regards
Peter

Originally Posted by Stustoys

Hi Peter,
It doesnt ring any bells with me and google cant find one.
If someone here will doesnt know of it we'll need some pictures.

Stuart

p.s. Its likely that the change gears are pretty standard, but with pictures we wont need to guess.

Morning Stuart
pictures uploaded
Cheers
Peter

Hi Peter,
The E2 you are looking at (0.25) is for metric thread cutting.
E8 would be your slowest speed for any gear train setup.
I'm pretty sure your gear train isnt set up correctly so those charts wont be correct anyway.(edit*I take that back, it may well be set up correctly for imp threading. again Pc should be able to help out)
Looking at the picture I think its set up (40x127)/(40x127). (dont worry if you dont understand the number just yet)

Could you count the number of teeth on these three gears?
Did you get any other gear with the lathe?

PC will likely put together a much better post that I ever will so I'll stop here

Stuart

It would seem if you positioned your levers to E/8 you would get a feed rate of around .008" compared to E/2 of .009".
As it is at the moment it appears that the 30 is driving the 127 in turn driving the 40.
Have a play around with the compound to see if you can get a slower feed.
Try changing the stud from 30 to 40,driving the 127,move the screw gear to engage the 120,move the 30 on the stud to the screw,change the levers on the quick change.

Peter. What is the diameter of the brass ? you may have the spindle speed too high MIKE..if all else fails , consult the destruction manual .

Hi PC,
Isnt putting a 30 instead of a 40 on the screw going to speed things up?
Wouldnt the slowest gearing with what he has be 30-127 120-40?

Stuart

Originally Posted by morrisman

Peter. What is the diameter of the brass ? you may have the spindle speed too high MIKE..if all else fails , consult the destruction manual .

Good Day Mike and PC and Stuart .
I will set it up like PC have said .
@ Mike. the Brass piece is 20mm dia.

@ PC . Thanks. I don't understand how those numbers work as you quoted yet so please edu me in a more clearer form if you would . in the mean time i will change it to E/8 and report back.
Cheers
Peter

Originally Posted by Stustoys

Hi PC,
Isnt putting a 30 instead of a 40 on the screw going to speed things up?
Wouldnt the slowest gearing with what he has be 30-127 120-40?

Stuart

Hi Stuart and PC.
I have just set it up on E/8 . look like it work good . much better finish on the surface .
however I may have another problem which is the run out of the chuck. I'm testing the cut on the brass bar . it stick out from the chuck about 70mm and cutting is about 50mm and I found in every 10mm cut I have about 2~3 thouds out . look like this.
17.50mm first 10mm and 17.47mm the next and then 17.44 or so in the next 10mm of cut.
is there anything's we can do on this run out ?

Thanks
Peter

Hi Peter,
Thats not run out in the chuck.
There are a number of things it can be, wear,deflection, twist in the bed, etc.
What depth of cut are you taking?
You are using HSS tooling?


Stuart

Originally Posted by Stustoys

Hi Peter,
Thats not run out in the chuck.
There are a number of things it can be, wear,deflection, twist in the bed, etc.
What depth of cut are you taking?
You are using HSS tooling?


Stuart

Hi Stuart.
oh I thought it is the run out of the chuck . so that is good to know.
the cut is only light cut 1/4 of the mm may be . I use HSS tolling .
so what do you recommend I should look at to fix this problem ? I really want the run out to be as low as possible .
regards
peter