What's New

A reminder...My website is for anyone interested in precision faceting using the jamb peg.
As I am not familiar with the Fralap or similar jamb peg machines, what I show throughout my site is based on what I am familiar with, and that is the BHandasa and KMT jamb peg machines.

I believe there will be an update to the Som/Kavi base which should encourage more people to give the jamb peg a try. Fingers crossed!

Everything on the previous pages still applies.

On the following page I have shown a few add ons I have made.

I have done a fair bit of work with the Som jamb peg , so have included my view of this machine.

I was going to do a new tutorial but just about everything you need to know is covered in "the start here pages", so I will just update those pages. If anyone has problems, then please feel free to contact me.

I was going to add something about "Why Use A Jamb Peg" Then I came acrossI Justin K Prim's video "Why Use A Handpiece Faceting Machine Instead Of A Mast?" He could be talking about the jamb peg, anyway I think it's worth a look, I have added it to the video page.

Finished Projects

All the indexers and pre-formers printed with ABS like resin.

New 64 index dops from KMT

The new 64 index dops from KMT are a vast improvement on the old ones. Make sure you check the flats for flatness, If there is an imperfection a quick wipe across a grinding lap will fix it.

96 index

The 96 index will cover most published designs, but not all. For example a trilliant can be cut but it's difficult because the mains on the trilliant design do not correspond to the mains on the 96 index.

Oversize full 96 index

The standard indexer is approx 25mm flat to flat. this one is 35mm so bigger teeth and more usable, a 5mm spacer is needed to use it.
May be useful for a complicated design.

42 index

This is a 7 sided full 42 index, only cut a couple of stones so far but seems to work ok.

64 full index

This is an experimental full 64, works fine and should last, only 4 indexes are used to cut a round brilliant. I also made a 96 index but the teeth are very small so may not last.

Full pre-former with cams

This is a full pre-former using cams. Works well but I only use it to form sides and ends on cushion cuts. Using it for other shapes can be very wasteful, I prefer to pre-form by eye.

Rounding Pre-former

This simple pre-former is only for rounds, working quite well, but requires the same diameter for all the dopsticks.

Rounding Pre-former

This is my preferred rounding pre-former. Different diameter dopstick are not a problem. Very easy and quick to use.

Transferring gauge

When transferring stones by eye there is usually some adjustment to be made after the transfer to get a good girdle. I made this tool to try to improve the process. Seems to work quite well.

Line it up

Emerald cut or square is aligned to the gauge, now the stone can be centered and girdle leveled. Use the same method for the pre-form.

Lined up

By keeping the dopstick centered between the lines and the dopstick aligned as in the previous photo, then parallax is not a problem.

Centering

Just need to move the stone slightly to the right. The alignment may not be 100% perfect but will be better than the usual method of just sighting the stone or using the faceplate and getting it close.

My personal view of the Som jamb peg

I have been using the Som jamb peg for a few months now, so here is what I think of it. The head is great, very well made and is equal to my Israeli machines, so very happy with it. The base is well made, speed control is good. It has thrown the drive belt occasionally, so maybe needs some adjustment.

Properly set up the Som is quite capable of precision cutting and with this style of jamb peg repeatability is excellent. The table attachment is easy and fast to use. Also the new dopsticks supplied with the machine are a vast improvement on the old ones.

I think there are three improvements which would make the Som even better. The height of the machine, the splash pan and and the need for a rounding pre-former. If you have a look at the industrial Brahm machine you will see the lap height is very low which makes for very comfortable cutting, similar to my Israeli machines.

The Som is quite high, so not very comfortable for me. I set it low in a desk which fixed the problem, but it's not very portable anymore. You can do the same if portability is not an issue. Just make sure you have easy access to the drive belt.

The pan is fixed in place which is fine for a mast machine such as the Kavi, but not if you need to do freehand work such as preforming and girdles, it needs to be a bit more flexible in it's use. This can be rectified by using a 3 piece plastic pan.

There is no way to pre-form a round stone, not a problem for a factory or professional cutter but could be a big problem for a newbie hobby cutter. A rounding pre-former is needed to make the Som complete.

I am used to cutting on the industrial Israeli machine which is very similar to the KMT Brahm machine, working position is very comfortable. I believe KMT can make make these improvements to make the Som an even better machine, more comfort, more portability, and as freight is a big consideration for an overseas buyer, less weight, cheaper freight! If they make the improvements it will make for a very user friendly jamb peg that will be hard to beat. Would I recommend it? Yes!

This is my personal opinion of the base, and may not apply to anyone else.

The Som Base

The Som

The Som base is very well built but quite high, approx 185mm from platen to desk, similar to most mast machines, I have seen worse so maybe not a problem for many people, but I like my comfort. You can always set it up to suit the way you cut, as I did.

The Brahm

This is what we want, as this is an industrial machine, working height and comfort is important when you have to sit and cut all day. I assume the platen height of the Brahm would be similar to the Israeli machine which is 30mm from platen to desktop.

My New Low Profile Base

I have been building my ideal low profile base, height from platen to desktop is about 85mm so with a 40mm thick armrest it's quite comfortable. I used a 12v motor and separate power supply and speed control so it's very quiet, the motor is unobtrusive, mounted behind the head. Weight is around 15kg inc. power supply and speed control. The 3 piece splash pan gate can be opened or closed in any positioned.

A Comparison

This is a comparison between the two base's.
The Som is 185mm from platen to desk.
New one is 85mm from platen to desk.
I think it would also suit the Kavi mast machine.