05-09-2013, 06:11 AM
Hi,
I have taught my seniors (well most of them)at high school to part off with HSS, without too many dramas.If they were able to manage this ,it should not be a problem for most once the basics are used and confidence is gained.
The following should help.
1. Ensure job is held securely in chuck jaws with a minimum of overhang. Dont use your live centre ,its a recipe for an accident.
2. Ensure tool is sharp, square to work and is at center height (or very slightly below).
With cutting edge slightly below, there is a tendency for the tool to flex away from the
work reducing damage of dig in if it occurs.
3. Ensure top slide is retracted so there is a minimum of overhang.
4. Move tool into position with saddle and then lock to bed.
5. Set speed. Say 83 ft minute for your aluminium.
If chatter is experienced, feed rate should be slightly increased and not a slower speed selected. It takes a while to develop confidence but a constant feed provides best results. I hand feed because I can feel the load against the cross slide wheel. I parted off a 1 5/8" washer in 316 S Steel tonite, using a hand feed, with no problems .If big lazy C shaped curls are coming off,you are on the track.
6. Lubrication. If fitted, coolant is set to flow in order to float the swarf away from the cut but if not available, use a small brush (or old toothbrush) and plenty of lathe cutting oil. WD 40 works ok on aluminium as does kerosene.
7. When parting off large diameters, take side by side cuts in initial stages to increase clearance and reduce possibility of swarf jamming in the cut and causing damage to the job or tool.
8.Cant peak for carbide as I have not used it, but HSS works well for me. Its ground on the front for clearance.Sometimes a tiny dip ground in the top behind the cutting edge works well as a chip breaker.If you have a Dremel tool ,do it with that.
I hope it helps you
Ozwelder
I have taught my seniors (well most of them)at high school to part off with HSS, without too many dramas.If they were able to manage this ,it should not be a problem for most once the basics are used and confidence is gained.
The following should help.
1. Ensure job is held securely in chuck jaws with a minimum of overhang. Dont use your live centre ,its a recipe for an accident.
2. Ensure tool is sharp, square to work and is at center height (or very slightly below).
With cutting edge slightly below, there is a tendency for the tool to flex away from the
work reducing damage of dig in if it occurs.
3. Ensure top slide is retracted so there is a minimum of overhang.
4. Move tool into position with saddle and then lock to bed.
5. Set speed. Say 83 ft minute for your aluminium.
If chatter is experienced, feed rate should be slightly increased and not a slower speed selected. It takes a while to develop confidence but a constant feed provides best results. I hand feed because I can feel the load against the cross slide wheel. I parted off a 1 5/8" washer in 316 S Steel tonite, using a hand feed, with no problems .If big lazy C shaped curls are coming off,you are on the track.
6. Lubrication. If fitted, coolant is set to flow in order to float the swarf away from the cut but if not available, use a small brush (or old toothbrush) and plenty of lathe cutting oil. WD 40 works ok on aluminium as does kerosene.
7. When parting off large diameters, take side by side cuts in initial stages to increase clearance and reduce possibility of swarf jamming in the cut and causing damage to the job or tool.
8.Cant peak for carbide as I have not used it, but HSS works well for me. Its ground on the front for clearance.Sometimes a tiny dip ground in the top behind the cutting edge works well as a chip breaker.If you have a Dremel tool ,do it with that.
I hope it helps you
Ozwelder