[joeavaerage]

Hi,
there is essentially two price grades.

The most expensive is forged steel. Forging is humanities oldest and still the best way to get high strength steel parts, like chucks, tools and so on.
Downside is that its really expensive.

The lesser option, or at least cheaper option is to cast, ranging from grey iron, the cheapest, through SG irons, right up to cast steel, with the price increasing
as the strength increases.

In the case of Vertex most of their chucks and vices are made out of Meehanite, a really good grade of cast iron. Its not as strong as steel, especially forged steel,
but it costs way less. Were you to use a lesser grade cast iron you can make them cheaper....and it seems that is what the Chinese do. Pay you money and take your
pick.

I paid $157NZD for a 100mm 3 jaw, I would expect to pay $400NZD or more for a 100mm forged steel chuck, if they even make little baby chucks by forging?

Craig

[atomarc]

While I'm not sure, I think this thread has gone off the rails. The original purpose of the thing was to machine little pieces of wood into God knows what. The funky little mini-chuck has morphed into a medium high end forged casting...all for little pieces of wood.
Did I miss something in translation??

Stuart

[viroy]

I just want to figure out exactly how to upgrade my 3-jaw chuck to a 4-jaw chuck, not conceptually, literally.
Was originally expecting something along the lines of 'you need this and job is done'.

I work with 1.5" square stock which is rounded to a 1" cylinder.
Need to be able to fit both in one chuck.
If there is a better way (I have not been able to find inserts which will allow holding 1.5" square in a 3-jaw)... im all ears

[atomarc]

Because the setup you had previously was custom made, not off the shelf, it's not realistic to expect to find off the shelf parts and pieces to swap a 3 jaw for a 4 jaw...you or someone else is going to have to modify whatever chuck you select to fit some type of adapter that mates to your gearbox. Because this forum is machine focused I assumed you had the ability to do these modifications.

The 'literal' way to achieve what you want is to first, select a 4 jaw chuck of your choosing. Look at the mounting configuration and draw up a plan for some type of adapter...it's that simple. That task is going to involve drilling or countersinking or machining, so unless you have those capabilities, you're going to have to have help.

Judging from your explanation of how you are going to use this setup, I would absolutely go with a self centering 4 jaw chuck versus an independent jaw version. Here is a small, inexpensive chuck that could be easily adapted to your shaft by merely turning off the flange and single point threading it to fit the chuck. Again, this requires machining ability.

https://www.amazon.com/TORRENS-Cente.../dp/B09C8MVDN8

Stuart

[joeavaerage]

Hi,

The funky little mini-chuck has morphed into a medium high end forged casting...all for little pieces of wood.

It was OP whom posted this:

There is only one 4-jaw vertex on ebay, but it's an 8" which wont clear my base and costs $900!!!

So he had inadvertently drifted from a cheap and simple chuck to do low load work into a much more expensive item more at home in an engineering workshop.
I tried to give a broad brush look at why there is such a variation in prices, but you are 100% correct, to do wood items then a cheap and simple chuck will be entirely enough.
Even the Vertex ones I linked to are more suited to engineering than woodwork, nice to have but not really required for OP.

I doubt he will find a self centering 4 jaw chuck in such a small size, an independent 4 jaw yes, but self centering......I think unlikely. They tend to be much bigger and back into the high
end engineering types.

Craig

[atomarc]

Hi,
I doubt he will find a self centering 4 jaw chuck in such a small size, an independent 4 jaw yes, but self centering......I think unlikely. They tend to be much bigger and back into the high
end engineering types.

Craig

Did you notice the link I included in post #24? https://www.amazon.com/TORRENS-Cente.../dp/B09C8MVDN8

[joeavaerage]

Hi,
yes I did see it ...and then forgot it, but yes that would be ideal for OP. He'll just have to make a new shaft with a MT2 socket.

Craig

[viroy]

I'm showing MT2 to be tapered and too small diameter.
Cannot use that at all... I need a 1" dia shaft with a .3" keyway
is there a shaft like that available with the proper threading for mini-chucks?

[atomarc]

Did you look closely at the link I supplied..that Morse taper shank unscrews which means you can screw in a shaft of your liking. I'm now understanding you don't have the capabilities to machine any metal items. The chances of finding the exact shaft configuration to fit that chuck (or any small chuck) and mate with your gear reducer is absolutely ZERO. Find a machine shop near you are have them make a shaft!!

Stuart

[viroy]

Maybe a 3-bolt pattern to 4-bolt adapter?

[joeavaerage]

Hi,
yes you could use an adapter, but if you don't have a lathe you're still going to have to get someone to make it for you.

An adapter is probably less accurate, a single solid shaft that threads into the chuck, or a flange with a raised centering boss and four retaining screws
would be more accurate.

Craig

[viroy]

I cannot find the spec sheet for my 3-jaw chuck, just havent had any luck identifying the brand logo stamped on it.
But I believe I can figure out the bolt pattern, might just put it on my scanner/printer, do a 1:1 scan and make a cad model from that.
Then get a new 4-jaw chuck, use the spec sheet to get the bolt pattern and add that to the cad model.
After that I can get a roughly 1/4" to 1/2" thick piece of 6061 aluminum and cnc mill a round adapter with both bolt patterns centered.
I would rather use steel, but my mill is not strong enough, I have cut 6061 before and it worked fine... any recommendations for metal to use?

Also looking for a recommendation on a good quality 4-jaw chuck, preferably under $100. It must be a bolt pattern mount, not shaft mounted.
For clearance, There is 85mm between the center of the chuck and the base... so a 6" chuck will fit, but with only 17mm clearance for the jaws to expand outside of the chuck diameter.
So a 4"-5" would probably be wiser (I can fully expand my current 4" chuck and the outside edges of the jaws just barely clear the base.)

[viroy]

Is there a way in solidworks to import an image to use as a stencil?