Faceting machine talk and ideas

Lets talk about all your best ideas and features you would like to see on a faceting machine and all your restoration projects. Ask any questions about motoring,dop sticks, how well you rate a machine and where to get help with your DIY machine projects.

SCORING COPPER LAPS
I use copper from 250 up to 1900, is there any benefit in scoring to top end laps for better bort retention?

I never score copper laps. They are usually half hard plate or bar stock. this means a diamond particle wont embed as deep as in an annealed lap. So scoring the lap will ad to grinding but will affect the finish greatly. I also don't score laps I instead knurl them using a straight medium hand held knurling tool. This action raise the surface of the lap without any metal being removed and creates thousands of small impressions for your diamond and lubricant to sit, feeding the facet as it passes overhead.
I do now manufacture a special copper lap for Gemcuts using sintered copper with a built in lubricant. This means the copper is slightly porous annealed and the built in lubricant allows the facet to glide smoothly over the lap. Its gives an aggressive but far supierior finish to any other copper lap at a similar price. Pre=polish is all about the best finish and this lap ticks all the boxes.

http://gemcutters.blogspot.com.au/

That's really useful for me. As a beginner purchasing a 2nd hand machine with lots of accessories I would like to optimize what I have at the moment $'s being the issue.
The copper laps appear to be in good condition, some even new, the bort is DeBeers (micron+mda) size's 1-2Um LX 1, 1.5-3Um LX 1.5, and another unfortunately with missing label with about 30 ct left. I mix up a paste using INOX- mx6.
What application method would you suggest?
I have flat lapped the copper laps using plate glass and wet n dry paper 280 then 400. Long process to get them flat.

Cheers Gordon

OK,
Never use wet,n,dry on any lap used for pre-polish or polish. You cant account for every particle of an abrasive harder than almost all the stones you are going to polish.
This is old technology and breaks every rule regarding contamination. The same applies to solvol soap. Use a green kitchen scouring pad even thou this is still and abrasive it is at least contained in a plastic surround.
Send them to me for re-machining with a diamond tipped tool. About $15 per lap. Better than $40 from another prominent lapidary shop.

Hi Rough2cut,

where is your workshop?
I have a few old copper laps that I could have resurfaced if possible.

Regards,

JM

I wouldn't use sandpaper either, the diamond bit tool is the best way to avoid trouble down the road. Rough2cut, you just made another idea pop into my mind: how about a resurfacing jig to be attached to the mast? After all a faceting machine's platter is like a lathe. With a sturdy mast it could be done, depending on the actual flatness level required. I suppose you can achieve insane flatness with your equipment though, which is always better for small stones like aussie saphs. Love me some brainstorming

Ive always said the third thing you should buy after a faceting machine and performer is a small metal lathe to make dop sticks and true up your laps.
Ive often had thoughts of a way to re-machine laps on your faceting machine, but the constant speed and feed to get that CD look finish on your lap just cant be done.
It takes a heavy duty quality lathe with a good diamond tipped tool and a little experience to do a lap that wont give you a dodgy readout on your faceting machine. That's the downside of digital faceting machines,they show up all the ripples and any lathe runnout and its interpreted as poor machining. Every lathe has runnout and you get a report with the lathe showing this when you buy it.A faceting machine is more accurate than most lathes.

http://gemcutters.blogspot.com.au/

Who knows if this is what I have after being shipped around the world .
But this is factory report from new machine . Always some flaws / innacuracy that gets set at an acceptable level . But as a newbie can't see the downside on a digital machine

I concur rough2cut, machining dops is one of the reasons why I'll get a decent metal lathe myself when cash flow permits.
Gotta love the guys at Ultratec. Really nice people there, with high standards. I bet you're highly satisfied with your V5 KingSolomon, judging by the stuff you're pulling out of it and your cutting rate.

Theres no downside for faceting, digital is the way to go. I had an incident a few years back where I had to redo a lap three times, each time I got what I called a perfect finish, and each time returned due to runout. I lost Time and Postage only to find out the digital faceting machine had a spindle issue. The lap was perfect. There is a point where a facetor has to learn to adapt to these sort of incidents as these days diagrams are to three decimal places generated by computer. most people with an older machine wont ever be able to achieve these parameters. Another was a comp cutter who showed me his stone saying that they were cut to computer angles and dead perfect asked me to tune his machine head which turned out to be out by 1.5 degrees. So all his work was out by that for at least a year or more. My lathe cost me $10,500
dollars and was purchased new and if you took a lap just machined on my other lathe and then machined it on the new lathe you can see the runout. I cant afford the $100,000 german made super lathe just to do a dozen redos at $15 ea. Im still having issues with my sintered systems that's why they aren't yet available on the market.
Runout on a sintered laps a bitch to fix, guess I need better machinery for that. Time and money.

Exactly, time and money. The reasons why I don't have the parts machined for my digital prototype yet. Maybe I'll hit the sweet spot when I graduate and get the teaching job and by that time you'll be ready to pull out those sweet sounding multilaps. I'm a strong believer of multilaps for some reason, although I understand they need to be respected more than regular single-grit laps. I've got a three-sector 600-1200-3000 for my proto and that will cover my basic needs for easy stones like quartzes and beryls. Definitely want to couple that with a dual-alloy polishing lap, and if I manage to get the machine to the trueness I want then both disks will be stacked for a single spindle-multidisk system. Small stones = small mechanical constraints on the lap. I know there are already many USB machines out there but the prices are insane, and for mass cutting of melee stones (and then buy an UltraTec for bigger stuff!) I can hit the $2K bar with no worries, since my design uses mostly standard industrial parts that can be bought even on ebay.

Thomas. you can access my machinery. I need an engineer to true up the slides etc for when I go into faceting machine production in 2015. Im looking to relocate to a bigger premises and share with someone who wants CNC gear, He does the drawing I do the machining. Any help is good help

If it weren't for the distance, I'd run to your place right now, but I'd have to cross the oceans first from France to Aussie... sigh

That's the problem with the web, we all seem so close and yet can be so far away. We will have to do it virtually stage by stage.If the cnc gear happens then all I need is a digitised drawing.

Yep. Want a preview of the current design as an appetizer?

I would.........please,please,please Sorry I got A little excited there.

3D render of the current design of the prototype, each subassembly in a different color. It actually relies mainly on standard industrial linear motion hardware, plus a few stepper motors. Only two are currently present in the 3D model (in the faceting head). Need me some cash to have the specific parts machined out of aluminium to go ahead!
As designed it can take stones from under 1mm up to 40+mm, although the goal is to use this for automated melee cutting. I have the "auto dopping/transfering/undopping" simmering in the back side of my head, but working prototype first!

You want to make one of these

That's it. But with stepper motors for automation Is that lower carriage one of your builds? Looks incredibly stiff, fit for the job!