Central Machinery 7x10 Headstock #3 Morse taper

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Blakd

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I have been looking at a few to many sites but unable to find the answer I am looking for. I am wanting to feed .875 aluminum rod through the headstock on my lathe. I have read that the largest bore you can go on the headstock is about an inch which is larger than I want to go but have seen one person say that they have gone to 7/8" which is about what I need. Is this feasible with a 4 inch 3 jaw chuck and the #3 MT on the 7x10? Also where would I get a boring bar for this, or would it be better to take it to a shop and have them do it?

Thank you in advance for the answers.
 
Well, the external size is 30 mm which comes in at 1.18 or so. I guess you could do it and see. It sure wouldn't leave much meat. Also you would have to bore out the chuck as well. Depends on how much you want to gamble and how much it costs to get done elsewhere. A new spindle is only $42 and a new chuck is about $109.

Personally, I would just look for a different lathe for the job.

What does the job look like? Maybe you could do something else like a steady rest?
 
The reason I want to bore it out for feed through is because some of the cuts I have received look straight but when chucked it takes about ten minutes to to true it up and then it is still slightly off. The size is set as what I will be running is 22mm and under, for the smaller diameter pieces I can make inserts to for the spindle that will true up the work pieces. I have looked and everyone says that the 3" chuck cannot be bored out to the size I want so I know I will need at least a 4 inch chuck.

thank you for your response.
 
You might want to research real bull. They have replacement spindles with a bigger bore if memory serves. You want to be sure of compatability before ordering also.
 
LEEQ said:
You might want to research real bull. They have replacement spindles with a bigger bore if memory serves. You want to be sure of compatability before ordering also.
Click to expand...

Found one of those on Ebay. Unfortunately, I believe it's for the two-speed, shorter heads from HF and Griz. It doesn't fit the newer LMS/MM high-torque model. Still trying to decide if I should throw it away or build some kind of indexer around it.

Bill
 
I bored out the 3 jaw chuck that came with my 7X12. I took it to 0.780. That was as far as I dared go. Much more and I would have eaten into the bodies of the screws that hold the scroll in. I didn't do anything to the spindle since the chuck was the limiting factor. I looked at the back of my 3" 4 jaw chuck. I wouldn't go up to 0.875 on it either.That would be too close to the nuts for the jaw screws.

Bigger lathe! Spindle bore is one of the main considerations in my upgrade to a 10X22, rather than the 9X20's.

Larry
 
The $79 3" 4 jaw chuck from LMS has a center hole diameter of 0.87" which will just clear your job. If you push your work into the spindle until it is close to the back of the morse taper you could get deeper into the spindle. The 4 jaw chuck would allow you to center your work accurately.
It may take you a long time to center your work at first, but with practice you can easily do it in a minute of two.

if you go to the lathe spindle for your lathe on LMS and click on Chris' tips, there will be a link to a dimensional drawing of the spindle. After seeing that drawing I'm not sure if you would want to open it up that far all the way through. You could bore it out partially through the spindle if you like.

Hope this helps,

Chris
 
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