Mounting 6" Bison set-tru on HF 8x12 lathe ...

[wquiles]

Instead of keep posting on Brian's thread about his new Bison chuck, I am creating a new thread to show the "slow" process of getting my 6" Bison set-tru chuck mounted on my Harbor Freight 8x12 (actually 8x14) lathe. Here is Brian's thread where you can see our brand new chucks!:
http://candlepowerforums.com/vb/showthread.php?t=192780

As a noted before, CPF member "dstutts" was generous enough to "donate" some raw al for this project - thanks again dude :twothumbs

Here is the new Bison chuck on top of the plate - I still have about 1/8" on each side of the chuck, so plenty of size to match the chuck's dia:

The plates are about 1.0" thick, should should be perfect for this project. About half of this thickness will be inside the rear of the chuck (for the set-tru feature), and the other half will be bolted to the spindle on one side and to the chuck on the other:

I started tonight shaping one of the plates. I first placed the new chuck on the Al plate and traced the chuks' dia. I traced it on the "outside" so even if I cut thru the scribe mark, the dia would still barely be larger than the chuck's dia:

I then proceeded to cut the corners to make it smaller so that I can actually mount it on the lathe, otherwise the plate would hit the ways - it took me like 4-5 minutes per corner:

I then proceeded to find the center of the circle:

Then I am using my laser pointer in my mini mill to perfectly center the plate:

Then I drilled a pilot hole with a center drill:

And that is how far I got today. I plan on working on the side of the plate that mates with the spindle first, then work on the side that mates to the chuck.

More to come later ...

Will




EDIT 5/27/08: So that you don't have to go through pages of photos, I am done with the Al version of the mounting plate, and this is how the chuck looks mounted on the Al plate. I am still going to work on a cast iron plate later on. Look at the OEM 4" chuck just for comparison:

Here is a 3D Mag for scale (you should not have that much outside the chuck unsupported!):

 

[Mirage_Man]

Sweet! I'm subscribed. I can't wait to see how this works for you. I know you're gonna like the chuck the first time you use it.

 

[ICUDoc]

Looks great wquiles- I wait for the next instalment with interest. I think your mill is the same as mine- lots of fun and learning ALL the time!!

 

[TranquillityBase]

Dude, your DIY threads are the best!

I can't wait to see the completed lathe.

Thanks for sharing,
TB

EDIT: Nice SPI chuck on your mill:thumbsup:

 

[PEU]

Nice work indeed, but I have my concerns about the durability of the aluminium mounting plate.
You used Alu for a particular reason?


Pablo

 

[wquiles]

Thank you guys. I normally post when I am done, but this time I will be posting as I work on it

EDIT: Nice SPI chuck on your mill:thumbsup:

Yep, after I used the built-in chuck on the mini mill I was not very happy with the lack of smoothness, plus it had a small amount of runout - not much, but it bothered me a lot. This SPI runs true, and it is ultra smooth :thumbsup:

Nice work indeed, but I have my concerns about the durability of the aluminium mounting plate.
You used Alu for a particular reason?

Alu was used just for convenience (this piece happens to be a high-grade 6061 used in the avionics industry). In terms of durability, please tell me more about what to look for - how can I tell while using it that this plate would not last?

Will

 

[will]

The durability would be more of an issue if you are taking the chuck off and on frequently. On my lathe I remove the chuck every now and then. Mounting it on the center of the spindle, if it were aluminum might start to 'ding' the raised areas of the plate. The chuck is harder and will be fine, the aluminum is softer and has the potential to get banged up. I suspect you will mount this and it will stay on permanently. If that is the case, Aluminum is fine.

We used to use machinist blue to do rough layouts on aluminum sheet material. It makes the scribed lines more visible. We also used wigglers and edge finders to locate points on the milling machine.

 

[Anglepoise]

Can not offer too much here as I am not familiar with the spindle on your lathe, but try and keep the overhang to an absolute minimum. This is a very heavy chuck for a light lathe and reduced overhang will help the headstock bearings live a long and productive life

 

[PEU]

Alu was used just for convenience (this piece happens to be a high-grade 6061 used in the avionics industry). In terms of durability, please tell me more about what to look for - how can I tell while using it that this plate would not last?

Will

I guess 4140 steel would do the trick, since its not difficult to machine and then you can heat treat it.
You can try your alu plate and keep this suggestion just in case


Pablo

 

[wquiles]

Cool - I understand now what you mean by durability


I got some more work done today (Sunday). I made the hole all the way through the plate, and made it bigger, one step at a time until 3/8":

I then started to bore the "pocket" that lines up with the shoulder in the spindle:

I used the stop in the mini mill to know when the right depth was reached (0.120"):

I kept the caliper handy so that I knew when to start making smaller cuts:

The target dia=2.833" - I stopped when the dial was around 2.831 and 1/2 or so:

When I tried it on the spindle, I was just 1/2 to 1 mil undersized - which is what I was hoping for:

I then used a diamond file and within a few minutes had it going all the way in for a presure-fit (of course, my friend the rubber mallet helped!):

Now I have to mark the 3 holes as precisely as I can so that I can drill and tap them, hopefully using the same 3 screws that came with the smaller 4" chuck:

Then again, although I don't have much room behind the spindle, I could use new, stronger, and slightly longer screws as well since the new chuck is "very" heavy compared to the OEM 4" chuck: ideas/recomendations here?

Will

 

[will]

There is a whole art to using metal files. The one caution, using them on a lathe, make sure you have a plastic handle on the end. If it ever catches, it can become a deadly instrument. the handle prevents it from being a 'spear'

I have 2 next to my lathe at all times, one triangle for deburring, and a flat file to get that last tenth smaller.

Will the size of the new chuck, much larger, have any effect on the motor?

 

[wquiles]

There is a whole art to using metal files. The one caution, using them on a lathe, make sure you have a plastic handle on the end. If it ever catches, it can become a deadly instrument. the handle prevents it from being a 'spear'

I have 2 next to my lathe at all times, one triangle for deburring, and a flat file to get that last tenth smaller.

Will the size of the new chuck, much larger, have any effect on the motor?

As always, thanks much for the safety tips :twothumbs

The original motor was "suposed" to be something like a HP, but we all know that in these chinese machines the motor was not nearly a real HP motor. The one I have is a top quality/brand "real" two HP motor, and I have power resistors to set the controler to 1/2, 1, and 1.5 HP, so the new much larger/heavier chuck "shouldn't" be a significant problem. Right now I have the 1/2 HP resistor in place just to get things moving, so I will experiment with several values once I have the new chuck mounted. I will report on how the weight/size affects the HF lathe

Wil

 

[dstutts]

Are the original socket head cap screws metric, or fine, or course thread? check them with your new chuck. You can get them at about any larger hardware store.

 

[wquiles]

The spindle holes are not threaded - these bolts thread on the OEM/small chuck. I am almost certain they are metric, but since I will have to thread the Al plate for these, I can use anything "good" I guess. I will go to the hardware store with one of them to get something as good or better

The question is: what would be the best way to get those holes marked on the back of the mounting plate given that I have so little room to do anything?

Will

 

[Anglepoise]

The question is: what would be the best way to get those holes marked on the back of the mounting plate given that I have so little room to do anything?

Will

Coat the back of the mounting plate with chalk.
Then fit it to the spindle flange and tap all around with a soft faced hammer.
Then carefully remove the mounting plate and you will have the three holes outlined perfectly. Spotface, drill and tap.
Good luck....

 

[will]

OR

Can you pick up the hole locations from the old chuck. ?

OK - old school - Piece of paper and a pencil, do a rubbing of the back of the chuck. transfer this to the new adapter. The new threaded holes don't have to be exact, there should be some leeway in their location.

If you have a rotary table for the mill. you can measure all this.

 

[wquiles]

Coat the back of the mounting plate with chalk.
Then fit it to the spindle flange and tap all around with a soft faced hammer.
Then carefully remove the mounting plate and you will have the three holes outlined perfectly. Spotface, drill and tap.
Good luck....

Newbe question: I can handle the drill and tap, but what exactly is to "Spotface"?

Will

 

[Anglepoise]

Newbe question: I can handle the drill and tap, but what exactly is to "Spotface"?

Will

Sorry...my slang. Use a centerdrill to mark the perfect center of the chalk outline before drilling through.

 

[VanIsleDSM]

It's aluminum, so it's soft, why not just cut one of the ends of the old screws in the shape of a transfer punch (or a piece of steel turned to the same diameter would be more precise) and then a thin block of wood up against the lathe to protect it.. slip screw in the hole up against the aluminum and give a little pry with a screw driver, that should leave you a good center mark for the holes... another idea anyway.

Awesome thread by the way.. I've owned my 7x14 Micro Mark for about a month now. I really like to see the methods other people use to make things, gives me lots of ideas.. like the cutter you have on the mill there, I don't have a mill yet, but I just thought about how easy it would be to use something similar to cut perfect circles for PCB boards or whatever else.. After getting the lathe sure didn't take me long to realize that I need a mill too... soon enough.

Good luck! looking forward to more updates and pics.

 

[modamag]

will, why aluminum not steel adapter plate since you're going thru the trouble already?
I'm just afraid of all the flexing.