Aussie Lapidary Forum
LAPIDARY => Gemstone Faceting => Topic started by: Skipper_52 on March 30, 2020, 09:09:29 AM
-
Hi all,
I am brand new to gem cutting. After I visited the Lazzardo Gem Museum in Oakbrook, Il. USA I became fascinated
with the idea of gem cutting. Being a mechanical type person I decided I was going to build my own table because I couldn't afford $3500.00 for a new one and not sure if I'd continue with another hobby. I am going to start posting progress pictures and design issues I've run into. I've read up enough to understand indexing and how important it is when transferring stones from one dop to another. I will never cut precious stones with this machine but have enjoyed collecting nice looking rocks on the shores of Lakes Superior and Michigan. So this post/topic will deal with the trials, failures and success's of building a faceting machine. I had bought a Covington 8" grinder at an auction for $450.00 U.S. to grind some cabochons (which I haven't done yet) and a tumbler to polish the lakeshore rocks. So please bear with me with this topic/posting and please jump in at anytime to turn me in the correct direction.
Thanks in advance,
Skipper_52
-
Page 2
This is the Chinese index arm I bought online for under $70.00. It does not come with instructions or a stop for the arm. The indexer and pointer are hard to read. The dop collet is 6mm not 1/4" and well built but there is no flat for indexing inserted dops after you transfer them. Back to the drawing board.
The black piece is a mount I designed and printed on my Prusa 3d printer. I am 67 years old, a pack rat for scrap material. I have a complete wood shop along with a cnc router I designed and built and am proficient in Autocad so I design and build most anything I want. Still looking to nail anything on 1st attempt though.
Skipper_52
P.S. Ok, it looks like I can't post jpg's here and will move all of this to the gallery section unless someone has another idea.
-
Hi Skipper_52. Welcome to the forum. Your jpeg opens for me. It is a good hobby when you are self isolating like most of the world is. Idle hands are the tools of the devil, so something to do is always welcome.
-
Damn,
I can't see the pdf. I started posting pics in the gallery but will come back here with the rest of them.
Thanks for responding
-
There is a line under your post. The pdf file is just under that.
-
The base is made from extruded aluminum pieces I salvaged from a podium I bought in an auction for $15.00. The top is 1/2" thick white corian that I had laying around and I machined the mounting holes and slot on my cnc. The 8" wheel is trial mounted for testing the motor. It will have a water tray under it.
-
The motor was a 12vdc windshield wiper replacement motor. I made the motor mount (hard to see) on my 3d printer. I needed the dc so I could control speed.
-
The digital scale was purchased on ebay for under $25.00. They can be had for cheaper than that now. It sits on the 3d printed mount with magnets. (see next few pics).
-
This is where the missing stop should have been. I designed and 3d printed it. The wing nut and arm are tapped out for 6x32 screws.
-
It needed a fine adjustment screw added to it. You can dial this in to .05 degrees. Way better than the visual protractor.
-
I modeled the digital angle mount to accept 1/2" x 1/8" rare earth magnets to hold the meter (which already had magnets in it). The mount came with a 64 index wheel but I purchased another (96 index) afterwards.
-
I bought a 8"x8" steel electrical box for the 12vdc transformer and speed controller. They were purchased on ebay for under $50.00. I added the fan to keep the components cool. You have to guess at the rpm's but the digital % readout helps. The motor did not have specs for max rpm's. It starts spinning at about 10% but there is no power there. I believe I could start grinding with 80 grit at about 20-25% power.
-
This will be good to follow. Thanks for posting.
-
As I said earlier I am a COMPLETE novice to this but enjoy building things. I might have a lot of questions. Dumb included.
-
As you will see later on I needed some 6mm shafting to fit the collet. I just found some online (d shafts) which make the indexing so easy (I think).
-
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.
-
Necessity still is the mother of inventions
-
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/
-
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
-
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.
-
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
-
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.
-
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.
-
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
-
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.
-
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.
-
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
-
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.
-
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.
-
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.
-
That's coming along nicely.
Water supplies are usually some variation on the Tupperware jug theme, translucent plastic so you can see the water level.
-
I agree that would have been nice had I had one but I figured I would throw a wood disk in it with a dowel rod attached in the center . The dowel rod will project through the lid so when the water drops the dowel drops giving me a visual.
-
Two bits of dowel, one inside and one outside, tied together with a bit of string.
Less likely to jam and stop reading.
Don't you just like old style technology?
Regards
Ghost
-
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.
Looking good. With your 45degree block/dop. Will the shaft slide into the collet more as I'd use it with a shorter shaft to reduce flex. The 3d printed bit is nice and chunky which will also help. If you haven't I'd consider roughing up the shaft and glue to the plastic aswell as using the grub screw. Depending on how you polish tables there can be quite a bit of horizontal force generated.
CheersMb
-
The collett dop shaft will be shortened. It is way too long right now.
-
Those digital angle blocks your using to set the facet angle are great. Even the cheap ones from the hardware are accurate to 0.2deg. Never used anything else for years.
Before putting the dopped stone in the 45deg dop, wipe an ink marker over the bottom surface of the 45deg dop and wipe it over a stationary lap.
Setting your hard stop against that when you have it right.
-
Look before you leap. I just saw a Graves attachment which basically is what I've designed. Duh. Anyway mine has the motor attachment too along with the different shape templates. I'll start posting pictures tomorrow. Like I said in the previous post, all parts that aren't metal are 3d printed. It took some time to print the carriage assemblies over 40 hours but the cost was minimal. Less than $20.00. The templates are only limited by your imagination.
-
I think what you've designed is a preformer. Quite a few faceting machine manufactures have made them. I plan to make one(similar to the gemmasta one and motorized as well. I plan to make design specific indexes. I'll be very interested in seeing your design (http://aussielapidaryforum.com/forum/Smileys/classic/smiley.gif)
Cheers
MB
-
I'm running the motor now. I still have to finish printing the base (7 hrs). Can you send a video here?
-
Hi MakkyBrown,
"The American Facetor" faceting machine came supplied with plastic preforming templates.
It also came with several design specific brass index gears, which had only some of the index teeth cut depending on the intended design.
Would make selecting the wrong index less likely.
Is this what you intend?
Regards, Ghost.
-
This isn't for faceting a gem but for shaping cabochon on the faceter wheel. Once you see the design you'll understand. All smooth rounds shapes can use the motor and be automatic. Anything with one or more flat faces can't use the motor because it becomes a spirograph of sorts. You will just lift the arm, spin to the next flat and drop the arm again. I'm sending an image of the cad model so you can kind of get a feeling before I send images of the finished prototype. If you have a 3d printer you can build this thing for under $100.00 U.S. with the motor. There is no need to change any index gears. The only gears are 1 to 1 on the drive motor. Rotation speed is controlled by a digital 12vdc speed controller. Gear motors can be bought from Sevocity.com and are available in configurations from .5 rpm to 950 or so. The slower the speed the more torque they have due to the fact they all have the same motor attached to the gear end. These images do not show nuts and bolts but the main 'machine' . All templates are designed within a 2" square. The stone template shaft (of mine) is 1" over the faceter grinding wheel. The cabochon can be scale by lowering (smaller) and raising (larger) the sliding mounts. There may be a slight bevel to some of the edges due to the lift of the dop rod by the template but these have to be rounded anyway when you do the dome grinding. Comments and advice are always welcome.
-
Hi MakkyBrown,
"The American Facetor" faceting machine came supplied with plastic preforming templates.
It also came with several design specific brass index gears, which had only some of the index teeth cut depending on the intended design.
Would make selecting the wrong index less likely.
Is this what you intend?
Regards, Ghost.
I was just going to base it roughly on the gemmasta preformer and cut custom aluminium cams. I've thought about design specific indexes as well then you can have the indexes at any angle and not limited to a tooth count.
ThanksMB
-
This isn't for faceting a gem but for shaping cabochon on the faceter wheel. Once you see the design you'll understand. All smooth rounds shapes can use the motor and be automatic. Anything with one or more flat faces can't use the motor because it becomes a spirograph of sorts. You will just lift the arm, spin to the next flat and drop the arm again. I'm sending an image of the cad model so you can kind of get a feeling before I send images of the finished prototype. If you have a 3d printer you can build this thing for under $100.00 U.S. with the motor. There is no need to change any index gears. The only gears are 1 to 1 on the drive motor. Rotation speed is controlled by a digital 12vdc speed controller. Gear motors can be bought from Sevocity.com and are available in configurations from .5 rpm to 950 or so. The slower the speed the more torque they have due to the fact they all have the same motor attached to the gear end. These images do not show nuts and bolts but the main 'machine' . All templates are designed within a 2" square. The stone template shaft (of mine) is 1" over the faceter grinding wheel. The cabochon can be scale by lowering (smaller) and raising (larger) the sliding mounts. There may be a slight bevel to some of the edges due to the lift of the dop rod by the template but these have to be rounded anyway when you do the dome grinding. Comments and advice are always welcome.
I'm really looking forward to seeing your machine Skipper.CheersMB
-
Can you post videos here?
-
KISS. (keep it simpler stupid) has occurred. I'm leaning towards Concept 1. They both work. Concept 2 will throw a unwanted angle to the edge of the cabochon. Concept 1 will need a balance rod attached/designed into it to adjust the pressure against the stone. The bearing mount that the template rides on in Concept 1 has to be re-designed. I've got the idea in my head but haven't designed it yet. The bearing should be mounted in a adjustable (sliding) mount which will make the scale adjustment way easier than shown. I would sure like your opinions and ideas to put this baby to bed. Ideally this mount could be converted on a sliding rod mount that could be attached to your cabochon machine, allowing you to move from stone to stone. Thanks.
-
I think it will be worthwhile if you see some pictures of a gemmasta preformer :), trust me it will help. I haven't got one but I bet someone on here has. It is basically what you are trying to build. If no one has one i know someone that has but I can't visit due to the virus but might be able to get some pics.CheersMB
-
Aargh I had pictures of the Gemmasta preformer until a few days ago when I had a computer spring clean. I sold mine with the gemmasta a few months back.
-
Double aaargh. I got mine spinning just fine. Guess I re-invented the wheel. Once I finish the parts I'll post the finished product. I'm thinking about mounting this on a table with a grinder. I have the arbor and electric motor but will have to buy the grinding wheel. Haven't figured out how to adapt it to Kingsley machine.
-
So... I had all these parts in the junk pile and decided to build a separate machine for preforming. I'm waiting on the motor belt which is coming tomorrow and the 6" diamond wheels that will be here next week. The water shield for the motor is just 1/4" baltic birch plywood. I will replace it with 1/4" lexan when it wears out. The water shield over the wheel is adjustable. I will eventually drill a hole through it for the water line. Questions? Please ask.
Skipper
-
God I hate these file restrictions
-
God I hate these file restrictions
We ask members not to post photos as attachments to messages as there is a size limit on that folder.
Please post them in the Media Gallery instead and then add it to your message using the BBC codes.
More info here.
http://aussielapidaryforum.com/forum/index.php?topic=4671.0
It really helps us out if you do it this way and is better for those viewing the thread.
ALF is provided as a free service to the lapidary community but it does cost us money for hosting space, etc. We choose not to offset that by selling advertising because I feel that is annoying to those using the forum but admin-wise, it is a lot easier for us to store photos in the Gallery folders instead of the Attachments folder.
cheers
Leah (admin)
http://aussielapidaryforum.com/forum/index.php?topic=4671.0
-
Thank you