[CadRhino]

What type of chuck do you have and why do you like it.

It looks like one can do just about anything with a 4-jaw chuck. Is the major drawback of a 4-jaw chuck is that it takes much longer for setups?

I like the versatility of a 4-jaw chuck but have a job coming up where I need to chuck up lots of the same size extruded aluminum tubing and a 4-jaw looks like it may take lots of time for each part.

I watched the Tormach 4-jaw chuck on a 4th axis and it looked painfully slow to setup.

Any one have any input?

Do any folks have both 3 & 4 jaw chucks?

Thanks so much,
Nathan

[05kevin]

Hi Nathan,
I have a 3 jaw chuck for my 4th axis. If I am machining square or rectangular stock I use the mill and circle mill one end of the stock round so I can use the 3 jaw chuck.

Kevin

[WOTDesigns]

You pretty much nailed it on the head Nathan.

I use both regularly on my lathe and occasionally on the mill. I keep the 3 jaw on all the time since I can change parts in 8 seconds which is handy. The sacrifice for the speed is accuracy. If I'm running parts that actually need better than 0.003 concentricity I pull out the 4 jaw. 20 minutes to change the jaw, oil her up, check the threads and align the part... And I sure as heck bill for that time.

With the 4 jaw I can easily get dialed into low tenths in 90 seconds. Mag base indicator, TWO adjustment wrenches to hit opposite adjusters and usually 3-4 rotations and it's on. Well, first set up is a little longer since you have to start from eye balling it in.

How much trade off (time/accuracy) both depend on the jaw and set up... And skill. A high quality well set up 3 jaw can get down to 0.001/0.002 repeatability pretty easily... Mine is maxed out at 0.003 no matter what I do, but that's fine for 90% of the lathe work I've ever done.

Brian
WOT Designs

[tmarks11]

The downside of a three jaw chuck is it is generally 0.003-0.005" out of tolerance. That is OK on a lathe, since once you turn the part, there is no error. Of course, as soon as you re-chuck it, you have a tolerance problem again.

Since you don't turn things to size in the 4th axis, but use it for repeated milling, I think you would be better off with a 4 jaw, which you can dial in to within 0.0005-0.001" quickly (with some practice).

Another option is to get a 3 jaw "true adjust" or "set true" (Bison or Buck) chuck, which has adjustment screws allowing you to dial in the part to 0.0005" with a dial indicator. Best of both worlds quick installation, quick dialing in... but kinda $$$.

[nitewatchman]

I use a 4-jaw chuck for large odd parts, a 5C Collet chuck for fast precision chucking and a #3 MT taper collet in axis center hole to hold TTS colet chucks for small parts.

nitewatchman

[mountaindew]

I have been looking at a 4th axis for months now and this information is great!
Anyone using 5c collet holder system?
I was working on 05kevins method of mill a diameter at one side of stock and then hold it in a 5c.
Or mounting material to A 1" dia fixture that can be held in 5c
Nathan do you have a 5c holder?
Do they have a precision locator pin to center in 4th axis?
md

[DareBee]

I use a 4 jaw SCROLL chuck.

[CadRhino]

Thanks for everyone's great input.
I was only looking at the chuck's Tormach sells. It sound like I could adapt other chucks if need be.
I will try the 4-jaw and get use to it first and see if the repeatability doesn't cost me to much time. Would be nice to have both we will see.
Best,
Nathan

[CadRhino]

I have never herd of a scroll chuck, I will look it up.
Thanks,

I use a 4 jaw SCROLL chuck.

[CadRhino]

Hi MD,

I do have one - this is the one I bought but have not used it yet,
5c Horizontal Vertical Collet Holder 0225 0202 | eBay

It does have a locator ring that will fit the 4th axis plate for alignment.

Best,
Nathan

I have been looking at a 4th axis for months now and this information is great!
Anyone using 5c collet holder system?
I was working on 05kevins method of mill a diameter at one side of stock and then hold it in a 5c.
Or mounting material to A 1" dia fixture that can be held in 5c
Nathan do you have a 5c holder?
Do they have a precision locator pin to center in 4th axis?
md

[pickled]

When using ground bar stock that is 1" or less in diameter for multi-part runs I use the 5C. 3 jaw is used on larger round stock or for "artsy" type aesthetic projects where tolerances are loose. Everything else gets 4 jaws of loving. Yes initial set-up takes time. I sure hate moving that 8" table off the mill table once I get it set and rocking out parts! The 6" is a LOT lighter (got it for my 770), but the rigidity and torque of the 8" make it my go to for rotary machining on the 1100.

[CadRhino]

Thanks for the insight, Pickled

When using ground bar stock that is 1" or less in diameter for multi-part runs I use the 5C. 3 jaw is used on larger round stock or for "artsy" type aesthetic projects where tolerances are loose. Everything else gets 4 jaws of loving. Yes initial set-up takes time. I sure hate moving that 8" table off the mill table once I get it set and rocking out parts! The 6" is a LOT lighter (got it for my 770), but the rigidity and torque of the 8" make it my go to for rotary machining on the 1100.

[CadRhino]

It sounds like one does not have to use a Tormach brand chuck but can use a metal lathe chuck (assuming it is in the same size range)? I assume it is helpful if there is an indexing/alignment ring/pin to center the back of the chuck with the 4th axis base plate to the face plate.

[DareBee]

I have never herd of a scroll chuck, I will look it up.
Thanks,

A 3 jaw is a scroll chuck, all jaws operate together with the chuck key

[Don Clement]

I use a Bison 5C collet chuck. For parts larger than the 1 1/16" collet ( shown below) I use a variety of step collets and internally expanding collets that can be turned to size on the lathe and used on the mill . Also I have a 5C mounted 5" 3-jaw with DIY adjusta-chuck that can be mounted in the Bison 5C chuck. I don't have to use a 4 jaw to get repeatable low TIR with this setup.

Don Clement

[mountaindew]

Don.
Thanks for posting pictures "worth thousands of words"
Does the 2nd picture show a internal expanding collet mounted in the bison 5c?
md

[Don Clement]

Don.
Thanks for posting pictures "worth thousands of words"
Does the 2nd picture show a internal expanding collet mounted in the bison 5c?
md

Yes.

[kstrauss]

I use an ER40 collet chuck with a MT2 shank and drawbar on the 6-inch rotary. ER40 collets are almost as accurate as 5C and have a larger gripping range

[Don Clement]

The thing about 5C is that they are not just for round parts less than 1 1/16" diameter. Standard off-the-shelf 5C collets can hold square, rectangular, and hex parts. I hold large diameter 3" to 4" diameter parts in a 5C chuck using a step collet. There are internally expanding 5C collets that hold parts on an internal hole. Emergency 5C collets come in brass, steel and nylon which can be machined to a complex shape in the mill. 5C is named after Cataract an early Hardinge company. BTW I like Hardinge collets the best of any 5C type http://www.shophardinge.com/categories.aspx?catid=6746 There are 4 and 3 Jaw chucks that fit the 5C chuck. Manual Lathe Chucks | MSCDirect.com I use 5C in my lathe and mill. I take parts made in the lathe directly to a 5C collet on the mill.

Don Clement

[CadRhino]

Don,
Thanks for the input and photos. Those are some impressive setups.
-Nathan.