Adapting a jet mini lathe to an indexer?

[oddcoach]

Hi Guys
I didn't realize I would create such a stir.
here goes
Jack my indexer has always been a direct connection.

43114.jpg
blame my poor photography skills.
the centerline of the lathe is 12" above the base.
as you can see in these pictures I have added a riser block of 3/4" the aluminum pieces in the picture.

43115.jpg

43116.jpg

[oddcoach]

i was having trouble adding more pictures so i added another post

Jim the shaft is custom made the stepper shaft is !/2 inch my shaft goes inside the headstock. this had a smaller dimension don't remember.what it was. I did he machine work myself and would behappy to make shafts and coupelers for any body that wants one. i tried a stock !/2 inch coupler shown here but it had too much wiggle in it for doing detail work.

43124.jpg

43125.jpg
all the connection are made with set screws no keyways.
The lathe I have also has a bed extension that just bolts on.

43126.jpg

43127.jpg

if you needed to turn something 24" you could cut the bed near the tailstock and slide the bed far enough away to do your turnings
the second set of feet would make the tailstock stiff enough. I have done some large turnings by hand. I don't think the stock indexer stepper has enough torque to do a 24" turning. i do 9 inch work on this setup and if i try i can overpower the stepper by hand. you are talkin gabout trippling the torque i have. I think you would be loosing steps left and right.

the set screws on the plate that holds the stepper motor made it very easy to align everything

43128.jpg

I checked the runout when i was done and it was only 1 or 2 thousandths. that system could easily be reconfigured to your kind of setup
hope this helps
John

[myxpykalix]

john, thanks for those extra pictures they help alot. I checked my indexer height from the base to center of shaft and it is 4 7/8" and the jet mini is 5" from base to center of shaft. Rather then raise the indexer and the tailstock and have to go thru the hassle of realigning them it might be easier to take the lathe to a machine shop and have them shave an 1/8th" off the bottom.
(After i reread that it might in fact be easier just to shim the head and tailstock 1/8th inch.)

[myxpykalix]

John,
Since you seem to have some background in metalworking let me ask you a question.

Since the aluminum plate for the indexer doesn't have a slot all the way thru like a lathe bed does to hold the lathe head how would be the best way to hold the lathe head to the aluminum plate for the indexer?

[myxpykalix]

Well it might be back to the drawing board. I went to our woodturners meeting and realized when i actually saw a jet mini that the motor is located under the lathe bed.
My initial thought was to just take the head apart from the lathe bed and attach it to the aluminum plate that comes with the indexer. Based in the way the mini is made that can't be done.
I may have to wait for the software revision for independant axis control after all...wheres bill young when you need him? lol

[oddcoach]

Jack
The head of the lathe does not really need the slot to hold it in place. Mine is just bolted to the bed of the lathe. it just uses the slot for registration. If the tab on the lathe does not fit the slot on the indexer you could make the slot wider just where the head will go or cut the tab on the head. I would recomend adjusting the slot since you could do it with the shopbot.
John

[myxpykalix]

upon closer inspection here is why this probably will not work for me.
I don't know why i didn't think about where the motor was mounted. So if you look at the picture you see the bottom of the headstock to center shaft is 5" however i did not take into consideration where the motor was mounted thus this would cause me to have to use the whole lathe height. Now we are talking probably 11+ inches to center of shaft and i lose a lot of turning height.

43171.jpg

[oddcoach]

why couldn't you make a change to your trough brackets to allow the motor to be below the existing brackets. just fit it between. even if you had to cut off the bed of the jet. or make a new bracket for the motor to hang below the indexer bed. you might have to get a longer belt.

[myxpykalix]

John,
A couple issues i have are, I don't want to cut my aluminum plate at all and where my brackets are I have to measure the space to see if a mini would fit in between.

My thought was to remove the wood base its sitting on and have a small trough welded on so i could sit the lathe in.
Look at this and can you tell me the length of your mini and the height from the bottom of the foot to the center of the shaft? (red and blue question marks). thanks

[guy_mathews]

Jack, this video may help.

http://www.youtube.com/watch?v=0I5NKZkLuw0

CAMaster used a Grizzly lathe head and tail stock to make our machine. They had it set up with a belt drive "which I told them would break" when I picked the machine up. You guessed it, it broke. I changed it a gear drive, and I am now in the process of turning it into a lathe. The gear drive allows me to produce large items with no movement from bit torque transfer. I am making a stepper motor lockout to disengage the stepper when I need to do lathe operations with the CNC. I will keep you up to date.