Faceter

[RoughCreations]

Thanks for the progress pictures. I like your way of thinking - sort of a faceting machine hack. Start with a Cultural Revolution tractor and turn it into a sports car, lol.

[Skipper_52]

Necessity  still is the mother of inventions

[Faceting Frank]

Hi Skipper_52, very interesting thread you have started.
I built my first machine back in the 1980s and sort of developed it over the years as I picked out all its faults and made mods to it.
One excellent home built machine worth looking at is.
https://www.jrobertslater.com/homebuilt-faceting-machine/

[MakkyBrown]

I really like that machine Frank.
Just needs a 5000cpr encoder instead of the 2000cpr then you don't need the DOC setup. I suspect I lot of people have been inspired to use encoders from Tom books and gone the 2000cpr. Which is a real pity as 5000cpr encoders don't cost a lot more.I'll might bookmark the page for another look down the track.Cheers
MB

[Faceting Frank]

Hi MB,
Found that link on the US guild forum and impressed with his machine and took his advice and bought Toms book on how to fit an encoder. Also like you realised that 2000cpr is no where near enough to keep an accurate record of where facets are.
At the moment to busy looking at  building a concave cutter attachment to have a go at one.

[MakkyBrown]

Hi Frank,
If you ever do an encoder chat with me Don't try and follow Tom instructions,  and only go with the angle displayed. I did rpm,  led, buzzer, clock, DOC, Storing angles and the angle is the only thing I really use. I wonder if a depth triggering beep(limited to once every 30 seconds so it doesn't annoy you) might be useful if daydreaming and over cut.I've got the concave machine to finish aswell Frank , when is that comp I have to cut a stone for flash?
CheersMB

[MakkyBrown]

Oh, 5000cpr, is 20000ppr so you get 5000 steps in 90degrees, or 0.018 degree steps. I'm finding it good enough to cut to the step changes.

[Faceting Frank]

Hi MB,
I never followed Toms instructions because I wasn’t confident enough to give it a go. I thought it would have been a simple plug it in and switch it on thing and the hard part would have been the mechanics involved in fitting it.
That would just entail making a new shaft the quill base pivots on, to accommodate it on the far end and some support bracket.
It would only be the angle part of the thing I would have used, too accurately start cutting the facet at the correct angle. I record all the facet positions with the digital height gauge I have on the mast and I use the dial gauge as a stop.
I’ve got a SMVector programable 3 phase motor on the machine, programmed with soft starts and stops as well as having a variable speed controller. So with a long dial gauge lever and getting the speed down to almost zero can get very accurate dial gauge readings.
Frank.

[MakkyBrown]

Hi MB,
I never followed Toms instructions because I wasn’t confident enough to give it a go. I thought it would have been a simple plug it in and switch it on thing and the hard part would have been the mechanics involved in fitting it.
That would just entail making a new shaft the quill base pivots on, to accommodate it on the far end and some support bracket.
It would only be the angle part of the thing I would have used, too accurately start cutting the facet at the correct angle. I record all the facet positions with the digital height gauge I have on the mast and I use the dial gauge as a stop.
I’ve got a SMVector programable 3 phase motor on the machine, programmed with soft starts and stops as well as having a variable speed controller. So with a long dial gauge lever and getting the speed down to almost zero can get very accurate dial gauge readings.
Frank.

One thing for sure it was not plug and play.     I spent quite a lot of time figuring it out but good for the brain.
MB

[Skipper_52]

Like I said in the beginning I am a novice so if I screw up on the terminology please correct me. I believe this is called a angle dop? Any way.. I got the 6mm D shafts yesterday. Pieces printed on 3d printers are close to accurate but occasionally need fine tuning. I printed this block and got lucky with the fit.

[Skipper_52]

I believe this is called a transfer jig/block. Anyway, this is mine. The D shafts are affixed within the sliding v blocks by the middle screws. All components slide. The dop ends are 3d printed. Notice the 2 set screws. Because the faceter arm collett does not have the D configuration it would be a bear to try and re-index a removed stone. Once the D shaft is in the collett I won't remove it until until the stone is finished but I can remove the dop "end", slide it onto the D shaft in the transfer jig and do the transfer onto the cone dop.

[Skipper_52]

The next few images just show different angles of the transfer jig. Notice the V configuration of the sliders. Once the upper block screws are tightened they are absolutely solid and align perfectly

[Skipper_52]

These are dop ends removed so you can see the cone and flat ends. I may not need to have the D slot in these because the set screws will self-align with the shaft flats. If this is the case I can have my son machine some brass dop ends out of 1/2" stock.

[Skipper_52]

This image show the alignment when the dops are placed on the d shafts. The dop are ends are printed with PLA filament. It has a melting point of 215 deg c. I have never tried the was affixing and planned on using epoxy because I can print as many of these ends as I need making them throwaways if need be. I'm hoping the was melts below 200 deg c.

[Skipper_52]

This home confinement is really pissing me off but necessary to avoid death. I can't get to the hardware store to get the misc stuff and have to order most of it online. I needed the water bucket so I used a empty plastic coffee can. I designed the bottom mount to slip on the extruded aluminum and epoxied it onto the bottom. The 1/4" npt fitting is brass. Still waiting for the needle valve to arrive before I can epoxy the drain mount in place. I need a 90 deg elbow attached to the brass shown so if I ever need to take the needle valve off  i can. It's coming along but I am not happy with the torque of the motor. It's nice because I can control the speed but I may swap it out for a 1750 rpm AC motor that I have laying around. It has way more torque but I can't control the speed unless I install a multi pulley system which would be a pain changing the belt.