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And here is where the shims sit on the toolpost:
Nuvver fing - The "centre" can also be used to "centre-bop" the work prior to drilling. (But back in my old "engineering workshop days" the old hands would burst into verbal abuse if they ever caught me doing this.)
Here is a photo of a piece of teflon in the chuck being "centre-bopped". Ya just turn the lathe on and "slam" the "tailstock" into the work (with the "centre" in place in the "tailstock" of course).:
Note: - The tailstock is slid along the bed to "slam" it into the work for "centre-bopping" but you can "lock it to the bed" (via a clamping nut) for drilling (where you move the drill forward via the wheel on the tailstock).
Actually, I think even those "old hands" would've allowed me to do it with "plastic" in the chuck.
As far as cutting speeds go, it's a bit like setting gas pressures on an oxy-acetylene set. Some people really "go to town" on being specific on what's required whereas I just say - "Go with what works".
Just remember that softer things like plastics need more speed.
If the metal is smoking and going blue - You're doing something wrong (or perhaps the metal you're trying to drill/turn is hardened or your cutting edge is blunt/chipped?).
Yet another fing:------- Constantly keep alert to methods of eliminating inaccuracy.
For instance - When I made those bushes I made them just 2 at a time. I cut 2 lengths of bronze rod - each a few millimetres longer than the combined-finished-length of 2 bushes. Then I drilled the pilot hole from BOTH sides in each of these lengths (so the holes met roughly in the middle to give a straight-thru pilot hole).
If I had drilled the pilot hole for all 4 bushes from the same end of the same length of rod - the pilot hole would have wandered off-centre by an intolerable amount by the time the drill was forming the hole for the last bush. (If you see what I mean?)
If you've got a lathe and want to try making something - I say "Go for it" (with or without night-classes) but keep all these points in mind.
Nuvver fing - The "centre" can also be used to "centre-bop" the work prior to drilling. (But back in my old "engineering workshop days" the old hands would burst into verbal abuse if they ever caught me doing this.)
Here is a photo of a piece of teflon in the chuck being "centre-bopped". Ya just turn the lathe on and "slam" the "tailstock" into the work (with the "centre" in place in the "tailstock" of course).:
Note: - The tailstock is slid along the bed to "slam" it into the work for "centre-bopping" but you can "lock it to the bed" (via a clamping nut) for drilling (where you move the drill forward via the wheel on the tailstock).
Actually, I think even those "old hands" would've allowed me to do it with "plastic" in the chuck.
As far as cutting speeds go, it's a bit like setting gas pressures on an oxy-acetylene set. Some people really "go to town" on being specific on what's required whereas I just say - "Go with what works".
Just remember that softer things like plastics need more speed.
If the metal is smoking and going blue - You're doing something wrong (or perhaps the metal you're trying to drill/turn is hardened or your cutting edge is blunt/chipped?).
Yet another fing:------- Constantly keep alert to methods of eliminating inaccuracy.
For instance - When I made those bushes I made them just 2 at a time. I cut 2 lengths of bronze rod - each a few millimetres longer than the combined-finished-length of 2 bushes. Then I drilled the pilot hole from BOTH sides in each of these lengths (so the holes met roughly in the middle to give a straight-thru pilot hole).
If I had drilled the pilot hole for all 4 bushes from the same end of the same length of rod - the pilot hole would have wandered off-centre by an intolerable amount by the time the drill was forming the hole for the last bush. (If you see what I mean?)
If you've got a lathe and want to try making something - I say "Go for it" (with or without night-classes) but keep all these points in mind.
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