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Old 11-29-2009, 05:41 PM   #1
coldte
 
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Default A Couple Of General Questions

Could you please advise on a couple of points i am not clear about ; The first concerns setting up to cut tapers using a taper jig i have made, how do you set the jig to the correct angle correctly ( it is a standard jig-you offset the bar) and do you cut the taper between centres or held in the chuck.
Second concerns Between Centre turning.is it possible without a faceplate and if so how ? as i cannot see it being done without using a lathe dog!
Thanks for your help
Coldte


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Old 11-29-2009, 05:50 PM   #2
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Default Re: A Couple Of General Questions

I've done turning between centers as follows:

Chunk of stock in chuck. Use compound to turn to 60 degree point. (Do not remove until job is done.)

Drill offset hole in end of stock that will face chuck. Loctite/superglue in short rod long enough to catch on chuck jaw and act as driver (dog).

If desired, after turning completed, machine off end where rod was mounted.


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Old 11-29-2009, 06:00 PM   #3
Tin Falcon
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Default Re: A Couple Of General Questions

There are three ways of cutting a taper in a lathe:
1) taper attachment
disengage cross feed screw and engage taper attachment.
there are a couple of ways of setting up you can set to the desired taper then use the cut and measure method to fine tune or you can set up a known taper and use a dial indicator to get the setup right before taking a cut.

2) Tail stock offset method again a couple of options offset the tail stock to obtain the desired results you will need to do a little math (trig)to calculate the offset based on the length of the blank and the desired taper. then use the cut and measure method to tweak it.
There are also tail stock inserts that will alw the offset without actually moving the tail stock. This ethod reqires turning over centers.

3) for short steep tapers use the compound set to the desired angle.

As for turning over centers You will need a dog but not a face plate some folks just turn a quick center in a chuck then use the chuck to drive the dog You cam make a dog if you do not have one.
Most of the time I just hold the work with a chuck or collet then support with a live center if needed.
Hope this helps.
Tin
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Old 11-29-2009, 11:39 PM   #4
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Default Re: A Couple Of General Questions

Here are a couple of pictures for you.



This first one is what Marv and Tin are talking about, using a center in the chuck. Start with a small piece of stock and turn a 60 deg included angle on the end. You have to re-true this piece any time you remove it from the chuck, but as long as you leave it there after being cut in place, it will run true.






Then make a simple drive dog. A hole for your work piece to go through. A set screw. A drive stud that is driven by one of the chuck jaws. That's it.


Not knowing anything about the jig you made, it's difficult to suggest a method for setting up to turn the taper you want.

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