10” chuck on PM-1340GT?

[Cletus]

I must have been about 7 or 8 years old, I remember going with my dad to collect a South Bend No. 4207 4-jaw chuck. Dad bought it to DIY a Christmas Tree stand (I kid you not). I held on to it, and got a back-plate for it when I got my Grizzly 9x20 lathe. Yes, I run it on the 9x20 with success, albeit at low speeds. Has worked quite well for me time and again. There she is on the Griz

 

[Dabbler]

I have an ultra light 12X37 lathe (just under 750lbs), and have an 8.25" 4 jaw chuck and an 8" 3 jaw chuck for it. Never had any problems running up to the 1800 RPMs it can go to.

At 300 RPM I put an off center billet of aluminum to make a 4 shot (in a row) injection mold, and then used a 5" billet to make a 6 shot mold by holding it off centre in my 4 jaw chuck. No significant vibration, but I think I slowed down the bigger one to 250 RPM.

I think it can work, if you are sensible about how you use it.

 

[mksj]

Not trying to derail the thread but, Mark, what should be the "normal" setting? I leave mine on 3s figuring it's easier on the gears and resistor. With the prox sensor it uses 1s anyway.

Normal braking time for mine is also 2.5-3 seconds, for threading and speeds below 500 RPM mine defaults to 1 second with the proximity stop. With a 10" chuck and holding large/heavy stock I would use 3 seconds stopping or maybe longer. Depending on the settings, VFD brand/model, braking resistor and program parameters the VFD may adjust the stopping time to prevent an over voltage event. It is more of a warning to not expect crazy fast stop times with large chucks and/or large loads, and also run the RPM conservatively. So I normally run 2-stage braking at 2.5/3 seconds and single stage at 1 second. The 2nd stage is activated by a separate VFD input. My systems/E-Stop deactivate the run inputs and the 2 stage braking for faster stopping times, but default 2-stage is switched in most of the time.

There are a few other factors to consider that are often overlooked, if you have a VFD set to stop at 3 seconds, this is the stopping speed at the maximum RPM (Hz), as you turn down the speed pot it also shortens the stopping time in a linear decrease. So 3 seconds at 80 Hz will be 0.75 seconds at 20 Hz. Braking time just sets the slope of the deceleration. Repeated quick braking can also cause the VFD to trigger a fault, so if you have several fast stops in quick succession, it is possible that the braking could fail.

The resistor will not fail, and I have never seen mine get past mildly warm, because the braking times are so short relative to the run times. It can add some mechanical stress to the drive train, but people use the mechanical brakes often minimal consequences. I still do not see the need for super quick stops if not necessary, so 2.5-3 seconds is fine. There are also some adjustments one can make to the braking curve, to soften the beginning and end of the stop (S-curve) but I use a linear stopping for the VFD because it gives a more predictable stopping distance when using a proximity stop system. If just manual stopping, then the typical default S curve is fine.

 

[wrmiller]

I ran an 85lb Bison 8" combination chuck with it for years with no problem, and Bill runs an 8" chuck which is a similar weight. As Aukai mentioned, it is more about balance and speed, and if you hit an oscillation point which is more likely to occur when using a VFD. As long as the chuck is running smooth, I do not see an issue. I would be uncomfortable running that size chuck at higher speeds, maybe over 600-800 RPM if it is running balanced, there is also a lot more centrifugal force/momentum with a large diameter chuck. If using a VFD I would set the braking to something like 3 seconds otherwise it may trip an over voltage error.

No reason for you to remember my setup, but you set up my braking with both a 1 sec and a 3 sec braking time. I use the 3 sec (when using the Big Chuck) any time I'm over 6 or 7 hundred rpm. When I'm running above 1200 rpm even the 3 second braking time can't stop this thing. It's a pretty big chuck.

You mentioned 'oscillation point'. Mine is just under 600 rpm to maybe 650. The only reason I notice it is because I have my light mounted to the back splash and it can wiggle quite a bit at the 'sweet spot'. Not much vibration though when I place my hand on the headstock. I consider it more of an annoyance than anything.

Oh, and this heavy arse chuck has been on this lathe for most of the last 5-6 years or so, with no adverse effects. Matt said this was a stout spindle, and I believe him.

 

[cday2021]

No reason for you to remember my setup, but you set up my braking with both a 1 sec and a 3 sec braking time. I use the 3 sec (when using the Big Chuck) any time I'm over 6 or 7 hundred rpm. When I'm running above 1200 rpm even the 3 second braking time can't stop this thing. It's a pretty big chuck.

You mentioned 'oscillation point'. Mine is just under 600 rpm to maybe 650. The only reason I notice it is because I have my light mounted to the back splash and it can wiggle quite a bit at the 'sweet spot'. Not much vibration though when I place my hand on the headstock. I consider it more of an annoyance than anything.

Oh, and this heavy arse chuck has been on this lathe for most of the last 5-6 years or so, with no adverse effects. Matt said this was a stout spindle, and I believe him.

how much does your stout chuck weigh? and what size is it?

 

[mksj]

Bill (wrmiller) has the 8" PBA Setrite chuck I mentioned earlier, it is 48 lbs and the back plate is 14 lbs. I use the 6.3" version on mine, they are very nice chucks and hold tight repeatability/accuracy. The 8" Bison combination chuck is about 20 lbs heavier than the 8" PBA. There are also direct mount 10" chucks in a D1-4 configuration which run around 65 lbs. The eBay 10" TMX is incredibly low priced compared to other major brands like the Gator listed below with 2 piece jaws.

PBA 825300 8

PBA Setrite Universal Chucks with Hardened Jaws for Maximized Clamping Force. The self-centering Setrite universal chucks from Pratt Burnerd America constitute a forged steel body, and they are manufactured with high accuracy for error-free mounting on adapter plates. These chucks assure double...

www.travers.com

PBA 805021 8

FeaturesFully machined. † Ships direct from factory.

www.travers.com

New SCA Sweden 10" 4 Jaw Independent Lathe Chuck. D1-4 Direct Mount $1805 List | eBay

Find many great new & used options and get the best deals for New SCA Sweden 10" 4 Jaw Independent Lathe Chuck. D1-4 Direct Mount $1805 List at the best online prices at eBay! Free shipping for many products!

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10" Bison 4 Jaw Lathe Chuck Direct Mount D1-4 +Hard Jaws | eBay

Find many great new & used options and get the best deals for 10" Bison 4 Jaw Lathe Chuck Direct Mount D1-4 +Hard Jaws at the best online prices at eBay! Free shipping for many products!

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Gator 1-301-1000 10-Inch 4-Jaw Independent Manual Lathe Chuck, PI4-10"A | eBay

Find many great new & used options and get the best deals for Gator 1-301-1000 10-Inch 4-Jaw Independent Manual Lathe Chuck, PI4-10"A at the best online prices at eBay! Free shipping for many products!

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[wrmiller]

Thanks Mark. That is a much better answer than I would have typed.

Edit: The Setrite chuck and backing plate are a bit more stout than a plain-back setup, but I'm not sure my arms would know the difference. I swear my PBA gets heavier every year...

 

[cday2021]

Honestly I'd probably prefer an 8" chuck with oversized jaws (like @davidpbest pointed me to): https://monsterjaws.com/10-oversized-extension-american-standard-tongue-groove-jaws-aluminum-2-ht/) as an 8" chuck seems better for general use.

There doesn't seem to be any oversized options for the 8" chucks, but there are for the 10" chucks (at least from monsterjaws.com)... since I don't have an 8" chuck I don't know if these jaws would actually fit on an 8" chuck. If anyone who has an 8" chuck can comment on if these would fit their chuck that would be helpful. Here's the dimensions:

@mksj -- I seen one of your older posts from several years ago on this forum commenting on the Gator chucks... I did a bit of forum research in addition and I feel like I should steer away from these chucks. I've seen that SCA and bison you listed above on ebay, but they have solid jaws and I'm leaning heavily toward the 2-piece jaw design. This bison chuck fits the bill to exactly what I want for a 10":

https://www.ebay.com/itm/153991945320?hash=item23daa29c68:g:F2QAAOSw6D9e~i9f

but $1500 for a chuck I'll rarely use is hard to justify...

 

[Janderso]

When I decided to buy a 4 jaw chuck for my 15" lathe, I asked around to see what I should get, 8", 10" or 12".
I settled for a 10" Bison with the T-slots.
I can barely lift the 10" I have the D1-6 adapter as well.
Something to consider

 

[Cadillac]

I have a 14x40 and I run a 10” bison 4j sometimes. Was lucky and found a fella selling on CL acouple years back. Nice chuck 2pc jaws practically brand new with a integrated D4 mount and has back bored out for weight reduction and balancing from the factory. Would let go for the right price.