HF 8x12 Lathe - Upgraded Replacement Motor

G

gorlosky

Active User
Registered
Joined
Jan 16, 2014
Messages
81
I am looking to replace the motor on the HF 8x12 Lathe as it seems underpowered on steel turning at 3 inch diameter, and I am only taking off .040 at a time, and it will stall.
Where can I find higher performing motor ? What is the CR CS about ? The present specs are:
Single Phase Capacitor Start CE
And Capacitor Running
Type JWL_7124 IP 44
350 watt .75 HP 120 volt 8 amp (yeah - it is not continuous duty 8 amp for sure)
60 Hz 1740 RPM
Ins B 5.4 Kg
CR 20 4/F 450 V
CS 40 4/F 250 V

(And I may as well take this motor and put it on the Drill Press to upgrade it :) )
 
holy cow, 1mm DOC on a 3in steel round on a tiny bench top lathe? Erm, I think you may be expecting a bit much from your machine. Try lowering the speed, hone your bit (you are using HSS bits, right?) and some cutting oil and you should be fine if you reduce the DOC a bit.
 
I agree that what you're doing is a bit much for that little lathe. You could upgrade the motor so it doesn't stall, but what about the rest of the machine? IMO continued use like that will accelerate the wear on your lathe considerably.

Just my $0.02,
Bill
 
Thanks for the feed back. I will ease back. I am running the lowest 125 RPM, but was using carbide inserts and will change to HSS tool.
Using cutting oil would reduce the drag of the bit by how much ?
 
you're welcome :) I'm no expert, but I use oil (dark sulphur plumbers oil FWIW) on steel so that the HSS bit doesn't overheat and dull, and WD40 on aluminium as it gives a better finish. Nothing scientific, but I get pretty nice finishes, especially with a very shallow slow pass at hihg spindle speed. Plus when you use cutting oil with steel you get these awesome little smoking chip comets shooting all over the place!
 
I agree you are trying to take to much for your lathe. and way to slow of rpm for carbide.
 
kd4gij said:
I agree you are trying to take to much for your lathe. and way to slow of rpm for carbide.
Click to expand...

Way too slow ??? I thought carbide had to be slower than HSS. I do have a chart for maximum SFPM, but not for minimum. Please explain more ?
 
Yes faster with carbide. In school some years back they mentioned up to 3 to 4 times faster than hss. The chart in my machinist handbook at times shows even faster depending on material.


gorlosky said:
Way too slow ??? I thought carbide had to be slower than HSS. I do have a chart for maximum SFPM, but not for minimum. Please explain more ?
Click to expand...
 
I own a Lathemaster 8X14 lathe which is the same as a HF 8x12. The owners manual says the motor is a 3/4 hp. I don't believe it since it draws 8 amps. However the motor in mine does seem to do the job. I don't know what kind of steel that you are cutting, but .040 should not be a problem (although it would not hurt to make smaller cuts). Is your bit height correct? If it's too low, it could dig in, I once had chattering for that very reason(my fault). Are your gibs set right? They could be too loose. Your speed might be too fast. Lathemaster sells a speed reducer pulley for around $100 to $150. In other words, before you spring for a motor, check and make sure that everything on your machine is adjusted correctly. This is tough little plane jane machine and I really enjoy mine. Good luck and it might be something simple.
Mark
 
You must log in or register to reply here.
Back
Top