Mounting a Chuck on Indexer

[pfulghum]

Kinda a continuation of ...

http://www.talkshopbot.com/forum/show.cgi?tpc=33571&post=74265#POST74265

There are a lot of "home made" indexers floating around, but I'm always faced with the same problem...

How to keep a lathe chuck (SuperNova) tight on the drive axle when software wants to turn the material both clockwise and counter-clockwise. One direction will tighten the chuck, the other direction will try to loosen the chuck.
Sometimes just a slight "loosening" can ruin a project.

Set screws kinda work, but my indexer uses the 18:1 Geared PK296. In this picture the indexer is a Harbor Freight "lathe" without the motor with a Stepper Motor attached on the far left connected through a coupler. My chuck would go on the actual lathe spindle.

I'm thinking of mounting a chuck directly on the 1/2" stepper shaft... But how?

I could use the Teknatool SuperNov2 Blank Insert from woodcraft http://www.woodcraft.com/Product/2005199/3928/Blank-Insert.aspx


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But the big question is how to keep the insert from rotating on the shaft AND keep the chuck from rotating on the insert.


What do you guys recommend?

-- Pat


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[myxpykalix]

pat,
Here is a pic of my chuck set up on the indexer shaft. You can see it has a keyed shaft and then set screws on what looks like an adapter collar.

I have had the screws on the locking collar work loose in the past but then i put some locktite on them and have never had any problems. I do think you will have to drill some kind of holes in the shaft for set screws as i don't think just set screws on the shaft will keep it from working loose.

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[pfulghum]

Jack,

Thanks for the info...

Is that a picture of a "real" shopbot indexer?
My motor shaft doesnt have a key, but it does have a "flat spot".

-- Pat

[myxpykalix]

pat,
that is the indexer bought direct from shopbot.

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[jseiler]

My gearbox has a 24mm output shaft (bayside ra115 from ebay) and it had a keyway. I took an angle grinder to the keyway and made a shaft flat. When I had the nova blank insert center bored, I had them install a 10-24 set screw in one of the hex flats. So far, so good, but I suspect its going to need locktite sooner or later. Its tighter than hell right now though.

[pfulghum]

Thanks John...
I will ask Dirk to bore it out for me on Fridyay AM.
Pictures will be posted for those interested.

I'm running a Oriental Motor PK296 18:1 1/2" shaft with flat, Gecko drive, and 36V DC.

-- pat

[wooddr]

Pat

I have it almost ready. We just need to take of a couple of thousandths to fit it to your motor.

Dirk

[jseiler]

I got my nova g3 chuck yesterday. Its got a set screw to hold the chuck onto the insert. I suspect that if you needed more holding power, one could add another set screw into the other side (the set screw is under the chuck key hole and there are two of those). I wonder if that part of the chuck is hardened steel.

On mine, it seemed to hold pretty tight, but time will tell. There's also a huge amount of machine oil on the chuck and I suspect that if you wanted to locktite the set screw down, you'd have to clean out the set screw hole really well.

I got the tailstock today...its a monster. Its a grizzly made for a 12" rotary table. Its about 45 lbs with a Morse 2 taper. Its height and angle adjustable. Nicely made for the price.

Good luck pat.

John

[pfulghum]

John,
Grizzly tailstock? Do you have part# or picture?

-- pat

[jseiler]

G9297 Adjustable Tailstock For 12" Rotary Table

http://grizzly.com/products/Adjustable-Tailstock-For-12-Rotary-Table/G9297

It looks nice to me, but I'm no expert on tailstocks. It comes with a dead center. The spindle is morse taper 2 so you can add your own live center.

Its heavy...about 45 lbs or so.

[pfulghum]

Here is my final setup...

That is a SuperNova II chuck on a "blank" insert that was precisely machined by "Dr. Shorty's Machine Shop". Index Motor is a PK296 18:1 Geared.



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Here is the complete indexer mounted down the X.

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The indexer headstock is mounted to a plywood sled. The sled's "Y" is aligned by special cleat on the sled. The cleat slides along the vaccuum table Y=0 edge.

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The tailstock is a Harbor Freight tailstock. I added a 4x4 piece of angle iron and a wood lathe bed.
Based on the spoilboard thickness, custom shims are made every time the indexer is placed in operation.

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Dust Collection for an indexer is a simple process, but multiple tools are required.

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Results:
Simple Rope cut on poplar column
"Patrick" was then V-Carved around the x-axis.
VCarve was done in Aspire with X/Y toolpaths generated.
Then a custom program I wrote to convert "Y" moves into "B" rotations. (and to do scaling and positioning).


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A rose (from Aspire provided clipart) imported into aspire and generated X/Y toolpaths (rough/final) created. Again my special program was used to convert/scale "Y" moves to "B".


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Thanks for all the help...
I hope this helps someone else.

-- pat