POTD- PROJECT OF THE DAY: What Did You Make In Your Shop Today?

[Almega]

I needed to cut some "lenses" with apertures to fit a specific dimension from tinted acrylic, 1/8" thick. To do that I had to make a plug cutter to the dimension. I turned what I needed from a piece of shafting I had left over and made it to fit a 3/4" collet and I hand filed the teeth with a triangular file. I mounted the sheet of acrylic to a piece of wood with 2-sided tape and clamped it up in the mill vise. Acrylic is touchy to drill and cut because it easily melts and will easily stress crack or chip so I carefully drilled the apertures and then carefully cut out the lenses with very light feed. A little touch up around the circumference with a file and they worked out perfect.

 

[ChazzC]

I needed to cut some "lenses" with apertures to fit a specific dimension from tinted acrylic, 1/8" thick. To do that I had to make a plug cutter to the dimension. I turned what I needed from a piece of shafting I had left over and made it to fit a 3/4" collet and I hand filed the teeth with a triangular file. I mounted the sheet of acrylic to a piece of wood with 2-sided tape and clamped it up in the mill vise. Acrylic is touchy to drill and cut because it easily melts and will easily stress crack or chip so I carefully drilled the apertures and then carefully cut out the lenses with very light feed. A little touch up around the circumference with a file and they worked out perfect.

Nice; you can also pressure turn a stack of material so you don't end up with the central hole. I've done this to make sight glass windows on oil reservoirs.

 

[Larry$]

Garden hose is 11.5 tpi.

I think that = 2.21mm pitch. My lathe will make 2.25mm pitch which on a short part should be close enough. .04mm off = .0015"
8tpi threading screw +30 tooth change gear from spindle to 127 idler, to 120 idler, to 40 input to the gearbox, select C/B/1 levers/knobs. Some one on this site ran the #s for all the different thread pitches you can get on various lathes by using all the possible combinations of change gears and gearbox options. You can likely find a close if not perfect match to any thread pitch you are likely to find.

 

[ChazzC]

I think that = 2.21mm pitch. My lathe will make 2.25mm pitch which on a short part should be close enough. .04mm off = .0015"
8tpi threading screw +30 tooth change gear from spindle to 127 idler, to 120 idler, to 40 input to the gearbox, select C/B/1 levers/knobs. Some one on this site ran the #s for all the different thread pitches you can get on various lathes by using all the possible combinations of change gears and gearbox options. You can likely find a close if not perfect match to any thread pitch you are likely to find.

I can’t get at my hose adapters to verify but regardless, 2.21mm pitch is 11.5 TPI: the can spout is 7 TPI = 3.63mm

 

[Larry$]

Garden hose is 11.5 tpi. I made this little thing to hook a garden hose up to a water meter connector.

the can spout is 7 TPI = 3.63mm

I guess my point was: check what metric threads your lathe can make against the imperial # required. My lathe will cut 3.60mm threads so nearly perfect match. & yes, I'd have to use change gears in addition to the gearbox settings.

 

[rwm]

Thanks for that pressure turning video! I had not seen that. I will be using that technique!

 

[ChazzC]

I guess my point was: check what metric threads your lathe can make against the imperial # required. My lathe will cut 3.60mm threads so nearly perfect match. & yes, I'd have to use change gears in addition to the gearbox settings.

OK, verified that garden hose appears to be 11-1/2 TPI, but is also only 1.03"/26.11mm (probably a nominal 1") OD vs. the nominal 1-1/4" OD for Alpha caps. Also looks to be less than 60°.

 

[woodchucker]

I needed to cut some "lenses" with apertures to fit a specific dimension from tinted acrylic, 1/8" thick. To do that I had to make a plug cutter to the dimension. I turned what I needed from a piece of shafting I had left over and made it to fit a 3/4" collet and I hand filed the teeth with a triangular file. I mounted the sheet of acrylic to a piece of wood with 2-sided tape and clamped it up in the mill vise. Acrylic is touchy to drill and cut because it easily melts and will easily stress crack or chip so I carefully drilled the apertures and then carefully cut out the lenses with very light feed. A little touch up around the circumference with a file and they worked out perfect.

Try water or I use simple green to help keep the melt down when cutting any acrylic or when drilling and need a super clean cut.

 

[Larry$]

Also looks to be less than 60°.

If we are talking duplicating some thread, the shape of the thread can be easily made to match most any form. Just grind a tool to match. A 10 or 15 minute job. I suspect rolled sheet metal threads have considerable tolerances. They don't have to tighten on each other, the travel to the end of the cap/gasket is again pretty sloppy. The same applies to the diameter, doesn't matter if it is 1" or 3"' as far as the threat pitch is concerned. Just turn the part to the required diameter and then thread it.

 

[ChazzC]

Try water or I use simple green to help keep the melt down when cutting any acrylic or when drilling and need a super clean cut.

We used a lot of acrylic back in the 70's and the department toolmaker kept a squirt bottle with water/dish detergent mix for when he was cutting threads and some other operations.