Face Plate Thread Depth

[Bill Mitchel]

Hello all

The threads on my face plate (Jet I think) start about 1/2" into the face plate. I don't know if I am explaining this clearly but the 1st 1/2" has no threads. I have a Rockwell 56-525 and the spindle has stick out 1". With the threads starting 1/2" into the plate I only get 1/2" worth of bite on the face plate so there is no way I can use it. Are there face plates that any of you use where the threads start sooner? It's a 3" face plate with 6 holes.

Thanks
Bill

 

[waltben]

That's standard as most all lathes don't have spindle threads going all the way to the headstock. If your Rockwell does, it's one of the exceptions.

 

[MichaelMouse]

You have an older lathe, from the days when reversing wasn't in vogue. Threads all the way was what they did then. Now they leave an area clear near the "nut" so they can use a locking grubscrew.
You should have no problems with three and a half turns as long as you face it up to the nut before you turn the lathe on. People who don't can wedge or cross threads with a greater number than that.

The Old Delta plates I had were, of course, threaded within 1/8" to the end. The 6" was a 1"8 L/R thread. Very handy. Also had a similar insert for my Nova chucks. http://www.packardwoodworks.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=lathes-acc-fp-delta LOOK AT THE PRICE!!!! For that you could get a nice pin chuck and ease your task immensely. That's what I used and still use. Faceplates are great for jam chucks.

 

[Bill Boehme]

Hello all

The threads on my face plate (Jet I think) start about 1/2" into the face plate. I don't know if I am explaining this clearly but the 1st 1/2" has no threads. I have a Rockwell 56-525 and the spindle has stick out 1". With the threads starting 1/2" into the plate I only get 1/2" worth of bite on the face plate so there is no way I can use it. Are there face plates that any of you use where the threads start sooner? It's a 3" face plate with 6 holes.

Thanks
Bill

Some lathes have a radial alignment register on the spindle between the threaded part of the arbor and the axial registration surface. The counter bored part of the faceplate's threaded recess is intended to provide a loose-fit mating surface for the radial register if there is one on your lathe.

I do not understand why you think that there is no way that you can use the faceplate. Since there is a half inch of mating threads, that means that there are approximately four full turns to hold it on. The rotation of the lathe is such that it will continually tighten the faceplate onto the spindle arbor so there is no reason to expect it to come off.

The alignment of the faceplate to spindle is controlled by the registration surface and not the threads so the number of turns is not really important as long as the total mating area is sufficient to prevent the threads from shearing off.