Adapting a jet mini lathe to an indexer?

[myxpykalix]

Based on the talk on the forum that independant axis control via software may be a while in coming, my thought that the simplest and probably cheapest alternative would be to mount a jet mini lathe inbetween the indexer and tailstock.
I see John Haggerty's setup but i'd rather have a direct connection as you can see my setup.

My questions are, has anyone set one up in line with the indexer? Do they line up properly? If not what did you do? If so what type of connection did you use to connect the shaft of the indexer to the lathe? I was thinking of using a double locking collar like on my legacy unless someone has a better solution. I would prefer some type of quick release system because i know some day i'm going to turn it on while it is still engaged to the indexer and would prefer not to screw anything up.

I have seen the jet mini's and if they are belt driven wouldn't it be easiest to just disengage the belt when in use as the indexer but still need a quick release from indexer shaft when using as lathe.

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[oddcoach]

Hi Jack
I agree with you about the direct connection. I did just disengage the belt. I hope these pictures make it clearer
John


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[myxpykalix]

John,
I was confused by your pictures from this post:
http://www.talkshopbot.com/forum/messages/33571/42458.html?1243955224
because it looked like it wasn't a direct connection. Based on your new pics you must have redone it?
Those help alot. A couple questions i have are this.
When you want to disengage the indexer it looks like you just loosen the screw on the head of the jet? If so is there any problems?

I have a bit of a problem and a difference then the way yours is connected you have the headstock and tailstock aligned by virtue of the lathe bed and have adjusted your indexer motor to that height.
Since my indexer bay is 8'+ I need to use the indexer head, then the jet mini then the indexer tailstock all in a line.
Do you happen to know what the height is from the bottom of the base of the jet to the center of the shaft is?
Because i'm thinking i'm going to have to make some kind of modification to accomodate any differences in height (if you can image putting the jet infront of my indexer as seen in the picture).
If i make any adjustment to the height of the indexer head i also have to adjust the tailstock to match. By just adjust the height of the jet inbetween that saves alot of work.

[jim_stadtlander]

Jack--- This has been a big delay in my final set-up as well. I want a set-up much like you are describing. I am getting closer to figuring out what it will take for me, but there are many problematic areas that have to be figured out. One problem solved leads to it creating another. Would you happen to know of a place to buy only a tailstock that would handle a 24" dia.

John--- In your set-up, is the shaft from the indexer to the lathe custom made? The indexer shaft is metric, and I am assuming the lathe is not.

[myxpykalix]

here is one thing i think might help. It is a shopsmith power coupler.

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[myxpykalix]

Jim,
I think any decent tailstock could handle a 24" stock. The problem you have is finding a suitable way to mount all this. What you have to do is create enough space above and below your router for your diameter.

If you are mounting your in the Y axis on the end you will also need extra space past the end of the table for diameter.
Here is my interpretation of what you would need to do is create a riser system to accomodate the diamter and i don't know if you have it.

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[jim_stadtlander]

Jack, I looked up that power coupler. Not much info on it. Doesn't say what the inside diameter is. You would need to match that up yo your indexer shaft. I think John's shaft is custom made to go from metric to inches. As far as the riser blocks go, that is what I probably will end up doing. I just was hoping there would be a better set-up for the tailstock. Each time you add a component like that, it adds to the chance of things not staying in alignment.

[myxpykalix]

Yes that is the problem, as crude as the drawing was you got the idea and as you said i too figured the problem would be alignment.

I had a heck of a time finally getting mine aligned and at this point don't have much play and know i'm going to have to redo it all if i add the lathe.
I might have to go back to using my legacy ornamental mill for turning symetrical profiles manually because its easy on it.

[waynelocke]

Jack,
I use a rigid shaft collar from McMaster Carr. They come in a wide range of sizes, including, I think, inch to metric.

Here is a pic of my interlock to prevent turning the lathe on when the indexer is attached. It is pretty low tech but works fine.
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[myxpykalix]

i'm not sure what i'm looking at, tell me what i'm supposed to see? (forest, for the tree thing)

[oddcoach]

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

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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.

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[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.

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

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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

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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.

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[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.

[myxpykalix]

I am probably going to put my plans for the lathe on hold seeing as Shopbot intends to include independant axis control i guess (I hope) with the next update according to ted hall. No set date for release but we'll just have to be patient. See (attn: ted hall post for details)

[oddcoach]

Jack
you can cheat right now. if you use an independent pulse generator. you could put a switch on the pulse leads of the stepper to go from indexing to you separate one. there are some cheap ones on ebay

[oddcoach]

If you are the adventurous type (most of us are) you could use one of these pic microcontroller and make your own http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2591
it comes with a usb connection and the software to program it

[myxpykalix]

John thanks for the tip but unlike most of you i'm NOT the adventurous type! I'm not good at electrical circiutry (other then house wiring)so i would be hesitant to try something like you suggest. Ted says the axis control will be out soon so i think i will wait for that.