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View Full Version : How NOT to attach your chuck to a rotary table and other difficulties



Teenage_Machinist
07-20-2008, 08:40 PM
I am the owner of a HF 8 by 12 lathe (like a 7 by 12 but much better made, and with a 4 inch chuck) and a Micro Mill (similar in size to the mini mill). I got a 4 inch rotary table and am planning to make a chuck adapter, but the fact that the chuck is exaclty the same size as the table makes it difficult. Any ideas? THe thing cannot be to long due to small size of mill.


Also.... How does mounting a slitting saw with a 1/2 inch hole on an 3/8 arbor shank sound for light use?

Does the rather loud ChunnunNUNnnUUnKa noise mean bad things/ does a mini mill usualy vibrate a lot?

Can I turn dull end mills into B-rate ones with a small hand stone or something?

aboard_epsilon
07-20-2008, 08:48 PM
your chukanuka noise is probably due to your dull endmills and too slow rpm of endmill ...are they yellow ....the next stage is sparks ...and then turning blue

:)

all the best.mark

Fasttrack
07-20-2008, 08:52 PM
Actually, my smithy makes that noise quite alot. Its usually because the belt tensioner mechanism has loosened up on me and you can watch the motor dance around a bit. I guess the mini-mill is probably gear driven though...

Is the noise coming from the cutting tool or from the "drivetrain"? Sometimes its hard to tell, since drivetrain noise is usually only heard when under load.

Teenage_Machinist
07-21-2008, 12:02 AM
It really is not very loud, and end mills are nearly new, they are definitely NOT hot and surface is smooth.
Any lathechuck-rotary table ideas?

Paul Alciatore
07-21-2008, 12:32 AM
Mounting a chuck to a rotary table has been discussed here many times before. Try a search. Here's some, but by no means all such threads:

http://bbs.homeshopmachinist.net/showthread.php?t=28622&highlight=rotary+table

http://bbs.homeshopmachinist.net/showthread.php?t=29457&highlight=rotary+table

http://bbs.homeshopmachinist.net/showthread.php?t=29251&highlight=rotary+table

http://bbs.homeshopmachinist.net/showthread.php?t=28697&highlight=rotary+table

I use a four jaw on the RT. This means that the chuck only needs to be approximately centered on the table (+/- 0.010"). I do this quickly with a adjustable square. The work is then centered to the accuracy required with the four jaws. This is both a simpler mount and more accurate than using a three jaw. My mount is just some bolts that pass through the chuck and into some tee nuts in the table's slots. This would work well with same diameter table and chuck.

Teenage_Machinist
07-21-2008, 01:11 AM
That would be easy. the prolblem is that the chuck is EXACTLY the same size as the rotab, and it is a 3 jaw so am leery of putting holes all the way through it. There literally is no more than a sixteenth of clearance around the table and chuck so a plate is not an option.

winchman
07-21-2008, 01:42 AM
Make a set of long pieces that fit into the slots in the rotary table. Drill/tap a hole through the part that sticks out from the table.

Now you can make some clamps to hold the RT, and secure the clamps with screws into the pieces in the T-slots.

A similar but stronger approach is to put a ring around the RT that is pulled upward against the bottom of the pieces in the T-slots as you tighten the clamp screws into the ring.

If you're not going to put large parts in the chuck, you can put another ring just outside the jaws instead of using individual clamps.

Roger

ptjw7uk
07-21-2008, 05:10 AM
Hi,
John Stevenson did a method of fixing a chuck to a rotary table where the chuck was the same size as the table. A search didnt find the thread but if I remember it used T-nuts and tapered screws in some configuration.

Peter

John Stevenson
07-21-2008, 07:41 AM
The post to show how to fit a chuck same size or even bigger than your table is here.

http://bbs.homeshopmachinist.net/showthread.php?t=20653&

.

Paul Alciatore
07-21-2008, 11:34 AM
John's method is quite clever and should work with any chuck. If you can put up with his comments about imaginary patent infringement, go for it. I must have missed that thread.

But if you use a three jaw, you still have to worry about centering. Best thing probably is to mount the chuck with the part in it and then center on the part. John's mount allows for that as the screws remain accessable.

Scishopguy
07-21-2008, 01:42 PM
Also.... How does mounting a slitting saw with a 1/2 inch hole on an 3/8 arbor shank sound for light use?

Does the rather loud ChunnunNUNnnUUnKa noise mean bad things/ does a mini mill usualy vibrate a lot?

Can I turn dull end mills into B-rate ones with a small hand stone or something?

As for the slitting saw, it is pretty easy to turn a bushing that will step the shaft size up to 1/2" and avoid possible disaster when the blade shifts to the side and breaks when it crashes into the work...seen it done before.

Don't have any experience with a mini mill but if they use a timing belt to drive the spindle it could be the source.

Dull end mills? You can hone the ends with a stone or diamond hone and make them workable in a pinch but they never are true and will always drag a flute, leaving marks in the best case. You prolly won't be happy with the results. Find a guy with a surface grinder or cutter grinder and have them resharpened. Well worth the few bucks to maintain the cutting tool.

best of luck with it,

Teenage_Machinist
07-21-2008, 05:31 PM
Thanks, people. "poor man's camlock chuck" is good. I was thinking of a largely unworkable idea involving pinch dogs.

John Stevenson
07-21-2008, 05:34 PM
John's method is quite clever and should work with any chuck. If you can put up with his comments about imaginary patent infringement, go for it. I must have missed that thread.



IMAGINARY ??????????????? Bah Humbug,.,,,,,,,,,,

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