Looking for a 4 jaw 5" chuck for my mini mill.

I have the 2338 4 jaw from LMS. I assume you mean you have a 7x lathe? I got it for my LMS 8x20 lathe. My lathe has electronic braking. With the 3” 3-jaw it stops fast but the 5” 4-jaw it takes a few revolutions then it stops.
This 4 jaw is a solid chuck. The jaws are mounted tight in the slots and the pinions are tight in the keepers as well. You’ll be happy with this chuck.
Just a recemendation, I’m pretty sure that the backing plate will have a 3 hole pattern and a 4 hole pattern as it is somewhat universal and you will have to drill holes to mount the chuck. Check with LMS on that to make sure. If you do have to drill additional holes, I recommend that you fill the unused holes with steel slugs. I didnt at first and I had a vibration at 600-700 rpm’s. I loctite 638’d the slugs in place and the vibration is gone.
 
I’m pretty sure that the backing plate will have a 3 hole pattern and a 4 hole pattern as it is somewhat universal and you will have to drill holes to mount the chuck. Check with LMS on that to make sure. If you do have to drill additional holes, I recommend that you fill the unused holes with steel slugs. I didnt at first and I had a vibration at 600-700 rpm’s. I loctite 638’d the slugs in place and the vibration is gone.
Thanks for the tip, I'll look into it if I buy a 2961 adapter for it , I may not have to since Roy is sending me his 4 jaw chuck which comes with a backing plate but I may still need to deal with the old holes or drilling new ones so your tip may come in handy, thank you for your post.
My lathe is 7 X 16 .
 
LMS shows the 5200 that Ken has is a 4" spindle model, while a standard mini lathe is a 3" spindle. The adapter I sent is for the 5" to 3" conversion. It has a 55mm recess diameter and Kens spindle is 72mm. So the adapter will need to have the recess bored out to 72mm and holes drilled for the larger diameter bolt circle and they are 3 8mm studs where the 3" spindle uses 6mm studs. I think it may be possible for Ken to make the adapter work.

Roy
 
I think it may be possible for Ken to make the adapter work.

I can't wait to work on that adapter Roy, I've done a couple of project like that so I'm hoping I could make it work, it can be tricky to drill the new holes just right but I'm thinking if I make the chuck fit nice and tight on the adapter, drilling the new holes will be much easier.
BTW, Thank you again Roy , Hope to get a chance to make it up to you.
 
I can't wait to work on that adapter Roy, I've done a couple of project like that so I'm hoping I could make it work, it can be tricky to drill the new holes just right but I'm thinking if I make the chuck fit nice and tight on the adapter, drilling the new holes will be much easier.
BTW, Thank you again Roy , Hope to get a chance to make it up to you.

Ken I think you can do it. The tough part is getting it chucked so it is bored out with no run out. As you said once the adapter fits tight on the spindle you can mark the mounting holes and drill and tap for 8mm studs. Fortunately The 55mm recess is already concentric with zero run out so you can use an indicator to get it centered for boring.

Ken you have already made it up to me. I am so happy that a good person can use it. I am tracking the shipment. It left Tulsa ,OK at 543 am.
If you have any problem with USPS tracking let me know. I can send you updates.

Roy
 
Locating and drilling the mounting holes is not a big problem but mounting and centering the back plate itself could be an issue . I am thinking of machining an arbor to fit in the center hole and tap a hole in the center of it and connect it to a long rod that would stick out from the back of the lathe so I can tighten it and then mic the backplate and center it that way, I'll see once I have it in my hands,. there could be other ways to mount the back plate on my lathe with the registration recess facing out.

I do have the tracking # you sent me but never checked the status yet , I'm not worried, in all the years of dealing with USPS I have never had a single issue with their service, same goes with our Canada post, I think by next friday or I'll have my chuck.:cheerful:
 
Back
Top