13" chuck for South Bend Fourteen?guess

[Glenn Brooks]

hi all,

I have a South Bend Fourteen variable speed lathe that I have been setting up as my primary chip maker. It mounts a D1-3 chuck - which has three studs.

Now the lathe has a 14" swing - which usually means mounting a six stud d-1-6 capable chuck.

My question is: how would I set up a 13" or 14" chuck on this lathe, with only a three stud d-1-3 backing plate?? My guess is that large a chuck would placed a lot of stress on only three mounting studs. Do I somehow add 3 more D1-3 studs to a mounting plate?

Maybe I have a whole other question e.g. What in the world where they thinking at SB when they started producing a 14" lathe with only a D1-3 mounting configuration???

I need to turn some 12" diameter locomotive wheels and a 14" smoke box front plate at some point, and would like to solve this riddle sooner than latter.

Thanks much for any insight on how to turn larger work.
Glenn

 

[Chipper5783]

A 14" lathe does not necessarily have a D1-6 spindle mount. My 15" has a D1-4, my 11" has a D1-4.

I agree it seems strange to have a D1-3 on a 14" lathe. Perhaps they wanted to keep the spindle tube very thick (sturdy)?

How to turn larger work? How about using the face plate? The trouble with using a chuck to go up to the maximum diameter is the jaws stick out. I had a 21.5" idler to skim, and I can take 22" with the gap section out. I made an adapter pilot and a good draw bolt and secured it to the face plate - cleared the bed by a 1/4 inch. The biggest problem was that my lowest speed, 45rpm, was too fast. I also had trouble getting the tool out far enough. I swung the compound around, to travel outward and held a grazed carbide tool in a boring bar holder. I found I need to sharpen the tool every third pass (250 fpm). It took a bit of time to set up, but the results were good.

http://www.hobby-machinist.com/thre...bigger-lathe-would-be-nice.53056/#post-446263

 

[Bob Korves]

I see no reason for a 12" chuck on a 14" lathe. It will have actually less capacity than a 8" or 10" chuck because of the jaws sticking out and contacting the bed. I would guess 10" would be about the max size without losing work holding capability on a 14" lathe, well, one with an actual 14" swing that is.

 

[Glenn Brooks]

Thanks guys, I found an 11" d-1-3 faceplate on line for a reasonable price, so think I will order it and give it a go. Also thought about turning the wheels on centers, after pressing an axle into place. Of course need a way to hold it to bore out the ID for the axle.

Glenn

 

[Asm109]

Rotary table on the mill can be your friend on large diameters.

 

[Glenn Brooks]

Woops, did some more measuring and actually confirmed the lathe is a D-1-4 configuration, NOT a d1-3. Both are three pin, however my pins are half way between 9/16 and 5/8" diameter. I read a comment on PM that some guy said he measured many different diameter pins from different chuck manufacturers, and that one has to be very careful, least you end up with the wrong back plate.

So I found the complete specifications for 'D' style cam lock chucks. Then compared diameters of the registers, OD of the cam lock assembly etc and determined the SB Fourteen is indeed a D1-4 configuration. There is over 1" difference in diameters between the D1-3 and d1-4.

Fortunately there are several D1-4 backplates on EBay, so sourcing one isn't a big deal.

Glenn

 

[Bob Korves]

D1-4 is a very common spindle, much more so than D1-3.

 

[Glenn Brooks]

Bob, yep. Iam happy I investigated further. Ordered a 12" faceplate off eBay with the correct D 4 series pins. Now I think I will look for a dedicated dog driver, as I've been doing more turning with centers. I have a big train wheel project coming up, that turning to centers would be ideal for.

Glenn

 

[Bob Korves]

I bought a D1-4 back plate to make a dog driver out of. I have a 8x8" square piece of steel to make the driving plate. Then I thought about the times I have wanted to turn between centers, and found that all the dogs in my assortment have different sizes, lengths, and bend locations. When I realized that I could not make a dog plate that would fit most, much less all of the things I might try to turn between centers, I regrouped. I am going to wait until the next between centers job and make the dog plate fit my back plate and then make a cut to hold the dog for that job ONLY. Then I will do the same on future jobs, using an existing feature if it happens to fit well enough to drive the dog. I will modify the plate if what is there does not fit. The last few jobs between centers I have just chucked some round stock in whatever chuck is on the lathe, 3 or 4 jaw, and then turned the 60 degree center in place. The center is more accurate, and the chuck can stay on the lathe for the vast majority of jobs. The chuck jaws drive the dog.