Collet chuck or???

I have been thinking about a collet device for my lathe (although it is a 9in. Logan w/spindle size 1 1/2 x 8tpi). What was originally offered on this lathe, and many others like Southbend, was a kit consisting of a tubular chuck holder w/large knob to tighten with, spindle collar, collet taper insert, and tightening spanner(s). Collet size is AC-30 from what I read in a catalog.
Now I have seen these "collet chucks" on venues like Ebay, offered for about $200./$250. They look great, and will take the commonly available collet #5-C. Considering how hard it might be to locate the older/original collet device for my lathe, does anyone have any experience with the newer collet chuck, or any suggestions how best to tackle this? Thanks!

The advantage of course of the 5C setup is
obvious, large capacity and cheaper and more
common collets.

I would also mention that Metal Lathe Accessories
has a similar setup to the bison one. If I
still were restricted to a 9" machine I would
probably go one of those routes.

I think others here have, and you should hear
the results right from them.

Jim

I have the Bison 5c collet chuck on my 9" south Bend Model A. It works very well, but I had to sleeve the I.D.,(mine was 1.509 diameter on the spindle) in front of the threads to make it run true. I also shortened the backing plate as much as possible to reduce overhanging mass. It has served me very well for the past 2 years.

Thanks Jim & ShelbyD for your thoughts. I have seen collet chucks offered by Bison, Eagle, and one that resembled the others but was unattributed. I was kind of concerned about the size of the chuck too. SD, you said you had to sleeve your unit. Do I understand correctly that the backing plate was a bit (spindle diameter) large so it was a loose fit on the spindle? I don't quite understand about the sleeving. You also mentioned reducing the length of the backing plate to get the chuck closer to the spindle shoulder, which makes good sense to me....

The locating bore on the backing plate, (locates on the straight diameter on the lathe's spindle nose) was 1.512". I removed the backing plate and faced it off to a length that would still leave me enough thread, then I bored it out to approximately 1.7500. I then turned and bored undersize a plug, pressed it in place and bored the plug to fit my spindle. The collet chuck runs within .0003 T.I.R. after refitting. You have to use great care indicating everything in. Good luck.

Put me down for liking the 3C collets.

I have other lathes that take the 5C so I keep the 3C's on my 9 inch lathe.

I have a 5C Kalamazoo on my Logan 820.

An advantage of the Kalamazoo is its low overhanging mass.

Another advantage is it is perfectly cylindrical, or nearly so, so it may be chucked in a 3-jaw for general purpose use, or chucked in a 4-jaw for zero TIR use, or offset in a 4-jaw for turning eccentrics.

Still another advantage is it can be mounted to a plate and mounted and dismounted on the spindle just as any other chuck, but without the flexibility achievable in a 4-jaw.

Finally, another advantage is it can be mounted vertically, as on a milling machine or jug bore. I believe this was originally its principal application.

This chuck is hardened through and through and will last a long time.

TIR when mounted on a plate on my Logan was in the low tenths.

The MLA chuck kit is a good option, but the collet taper is not hardened and ground, as is this component of most commercial collet chucks which use a steel insert (Sjogren, for example), or are all steel (Kalamazoo, for example).

A 9" dia. 5C Sjogren, when available, is a good investment, and is likely the longest running collet chuck on the planet (it's just passed its 75th anniversary of manufacture).

"Put me down for liking the 3C collets."

3Cs are OK, and much more obtainable than the 3ATs or other, proprietary 3's variations.

The 3Cs and 3ATs are interchangeable to some
large degree I think.

I had a machine that used what I believe were
3ATs and I found that by lengthening the keyway
on the 3C collets I owned, they could be used
quite well.

This requires a 1/8 inch carbide end mill or
slitting saw as the collets are heat-treated
and won't cut with HSS.

Jim