What is this chuck mount called?

[skogkatt007]

https://www.hobby-machinist.com/threads/my-harbor-fright-31316-8-5-x-18-lathe.109277/

I realize no one has the lathe in front of them. In the referenced thread for my Central Machinery 8.5" x 18" (a lie) geared head lathe, you'll see a photo or partial photo of the chuck plate. I don't know how to identify it.

It came with a stock 4" 3 jaw. I would like to add a 5" 4 jaw independent. Like this

https://www.amazon.com/gp/aw/d/B07JYVW43P/ref=ox_sc_saved_image_1?smid=ATVPDKIKX0DER&psc=1

Do I need an adapter?

6" is nicer

https://www.amazon.com/CME-4-Jaw-Independent-Lathe-Reversible/dp/B0CFRFYM5S/ref=asc_df_B0CFRFYM5S/?tag=hyprod-20&linkCode=df0&hvadid=660126325636&hvpos=&hvnetw=g&hvrand=6507304113489619133&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=200504&hvtargid=pla-2208792739809&psc=1&mcid=190476d4a6af33feb5534e2d1e9e3b3a

 

[SLK001]

Do I need an adapter?

Most new chucks require a mounting plate specific to your lathe. The 6" says this specifically, but the 4" is silent on the matter. I would say that since it doesn't say what lathe that it fits, you will need a mounting plate.

 

[Larry$]

Figure on machining the back plate to fit the chuck. It's not difficult. Just mount the back plate to the lathe and turn the face of it to match the back of the chuck. You want a close fit so they will go back together the same each time you take them apart for cleaning and lubricating the internals of the chuck.

 

[markba633csi]

I think you have what's called a flange mount- Little Machine Shop has adapters I believe in that style
Some machining may still be necessary

 

[Smithdoor]

https://www.hobby-machinist.com/threads/my-harbor-fright-31316-8-5-x-18-lathe.109277/

I realize no one has the lathe in front of them. In the referenced thread for my Central Machinery 8.5" x 18" (a lie) geared head lathe, you'll see a photo or partial photo of the chuck plate. I don't know how to identify it.

It came with a stock 4" 3 jaw. I would like to add a 5" 4 jaw independent. Like this

https://www.amazon.com/gp/aw/d/B07JYVW43P/ref=ox_sc_saved_image_1?smid=ATVPDKIKX0DER&psc=1

Do I need an adapter?

6" is nicer

https://www.amazon.com/CME-4-Jaw-Independent-Lathe-Reversible/dp/B0CFRFYM5S/ref=asc_df_B0CFRFYM5S/?tag=hyprod-20&linkCode=df0&hvadid=660126325636&hvpos=&hvnetw=g&hvrand=6507304113489619133&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=200504&hvtargid=pla-2208792739809&psc=1&mcid=190476d4a6af33feb5534e2d1e9e3b3a

Just did that a 5" 4 jaw .
I choose a 5" it hurts less if I drop it on hand. I plan on making a 7½ face plate too.
The backing plate came from little machine shop.

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The premier source of tooling, parts, and accessories for bench top machinists.

littlemachineshop.com

 

[skogkatt007]

How do you match the angle of the raised boss?

 

[Smithdoor]

How do you match the angle of the raised boss?

Sounds like A tapper.
A chuck needing a backing plate is straight there is no tapper.

Dave

 

[Smithdoor]

How do you match the angle of the raised boss?

Here chart on backs

Lathe Chucks

This page provides lathe chuck capacities and mounting dimensions.

littlemachineshop.com

Dave

 

[markba633csi]

Taper?

 

[rdean]

I made this adapter close to 30 years ago for a new 5" three jaw but I can't remember how I did it. The flange had to be modified to allow for the three mounting bolts of the new chuck. I still use that lathe some to this today.

Ray