PDA

View Full Version : changing chucks on my drill press



mikem
05-10-2003, 02:15 PM
Having read about the rohm self-tightening drill chucks on an earlier thread, I decided to try one but I can't get my old jacobs 33MT chuck off of my delta radial drill press. It is a little on the light side--more made for wood than metal. It wasn't tightening well enough and my chuck key is rounded off and none of the new ones I tried seem to work. I got the new chuck from Enco for $55.

Once the jacobs fell off when I was trying to do some light milling and I might have used some brand x Loctite to stick it back on.

What bright ideas do you guys have to get the old on off w/o wrecking the bearings in my spindle? Do I need to use loctite on the new one to keep it on? I have a mill now and won't be abusing it anymore. Thanks--Mike.

docsteve66
05-10-2003, 02:58 PM
Mike: If you just chuck an end mill back in the drill press and try to do some more "light milling" the chuck will surely drop out again. I speak from experience, I have tried to do some light milling in several Drill presses with Morse tapers. Despite Locktite, superglue, pin punching the taper, set screws and I don't remember (or more likely) or wish to admit some other things, the damn things would always drop out sooner or later. Use cutter natural downpulling tendency to your advantage.

Joel
05-10-2003, 03:04 PM
If you just need to get the chuck off the arbor, use chuck wedges. You can apply some heat and pop the chuck with a hammer. This is the recommended way to break the loctite bond.
I believe this drill press does not have a hole in the spindle for an arbor wedge. If your new chuck has a different taper, and you need to pull the arbor, lay drill press on it's side and lock spindle down, wedge chuck off and apply heat. Wrap some wet rags around top of spindle to keep heat at bay. Use fairly high heat to keep from heat soaking spindle. When it gets warm, pop it with a hammer. May have to lever out with vise grips or something.
Best I can come up with, Joel

mikem
05-10-2003, 04:29 PM
Thanks for the advice.

Joel--the taper is the same so I can use the new chuck as-is. It is a little longer, so I'll lose a little vertical capacity. It does look a lot beefier than my jacobs.

Steve--have you had a lot of trouble with MT-33 taper or just when milling? Maybe I should have just bought a better drill press instead of a new chuck? What method of chuck attachment is used on good drill presses?

Thanks--Mike.

Joel
05-10-2003, 09:55 PM
mikem, I have one of these drill presses, they are quite handy due to their large swing capacity. I use it only for light duty tasks, mostly woodworking. It is just too light and flexible for much else. I augmented mine with a large/heavy drill press. Both use morse taper to jacobs taper arbors for chuck attatchment.
Do you have wedges? If not, you can use whatever you have laying around.

George Hodge
05-10-2003, 09:56 PM
Has anyone else noticed that some Jacobs type chuck keys slip way too easily? I found that the outer shell was pressed too far,on one of mine,so that the gears barely meshed. Put the key in the hole and held it with a rubber band,pressed the sleeve with the teeth toward the key and presto,the key doesn't slip now.

Forrest Addy
05-10-2003, 11:55 PM
Get second shank. a chuck without a shank is not only useless but a frustration when you need it.

mikem
05-11-2003, 12:22 AM
It doesn't look like the chuck wedges will work. When I look up at the bottom of the quill I think I see the bearing. I can't pry against that, can I?

I chucked up a 1/2" milling cutter and tried to cut a piece of steel and chattering the bit to see if that would vibrate it loose, so far no luck.(steve's idea)

The ring on my jacobs chuck is too high. I think that is why the keys don't grab. If I fix that I could return the new one--but the new one looks so cool, I think I'll keep it.

The arbor is attached into the quill, so having another arbor isn't going make it easier. (forrest's idea) Once I get the new chuck mounted, it will stay on!

Could I chuck a bolt into the chuck and thru the table and use a nut to pull the chuck loose or will I just break something? Maybe I can borrow a friend's chuck wedges tomorrow.(as long as I don't ruin my quill bearing.) So far all I have done is jimmied up the top of my old chuck. Thanks for all the ideas, but don't give up yet!--Mike.

[This message has been edited by mikem (edited 05-11-2003).]

Joel
05-11-2003, 01:41 AM
Do not pry on your bearing.
There should be a small shoulder on the morse taper side of the arbor. You need to wedge between this shoulder, and the top of the chuck. If you have no way to pry from there, pry on both sides of the sindle shaft (where the bearing is pressed into).
I don't think your bolt idea will work for a couple of reasons. If you still can't get it, there are more involved ways.
Perhaps you should fix your old chuck and put the new one on that mill you've always wanted. http://bbs.homeshopmachinist.net//smile.gif

Thrud
05-11-2003, 02:16 AM
mikem:
Fully extend the quill and see if there is a slot in the quill to extract the Morse taper shank with a wedge. If not, then the spindle nose has an integral JT33 chuck mount and you will need to make or buy wedjes to remove the chuck. Since you used a "loctite" material when it fell off last time, heat the chuck up with a propane torch to about 250-350* - this should break the adhesive bond. Then use the wedges to remove the chuck.

To mount the chuck, clean the socket and taper with laquer thinner or acetone and heat the chuck in the oven to 200*. Take the chuck out with gloves on and place on the spindle give a sharp rap (use discretion here!) on the nose of the chuck with a soft face or dead blow hammer. Let it cool to room temp before using. It should never come off again if you only drill with it.

If your machine has a morse taper, get a new shank (Hardened & ground is best) for the chuck. Follow same heating instruction, but also place the new shank in the deep freeze for 1 hour. When the chuck is ready, take the shank out , wipe it dry and place immediately in the chuck and tap(quick sharp rap, again) the shank into the chuck with the dead blow hammer. Let the chuck and shank return to room temp. before using, carefully clean the drill socket out with thinner and wipe with a clean dry towel, insert the taper into the socket and give it a light tap - if it falls out, then next time put the chuck and shank in the deep freeze for at least 1 hour. Wipe shank before inserting in the socket and give it a sharp rap on the chuck nose to seat the MT. It should never come out with out the assistance of a wedge again.

DR
05-11-2003, 10:37 AM
Years ago I had what I think is the same drill press you have. Chucks coming off in use were common with that model.

The chuck is on a 33 Jacobs taper mount on the end of the spindle. The spindle is fairly soft.

Pull the spindle out, drill a cross hole in the spindle for a roll pin to be used as a shoulder for the chuck wedges. This is the way Jacobs recommends removing chucks when there's no shoulder.

mikem
05-11-2003, 11:54 AM
Thanks for all the input. It is a Jacobs taper, not the MT that I said in my first post. Sorry for the misinfo. There is no slot to drive out the arbor. I think the spindle is one piece. I think I will try the heat to see if I can get it loose(what thrud said) and then maybe try milling again if that doesn't do it. I think that 33JT is too short and too much taper for milling and maybe that will vibrate it loose.(will try steve's suggestion again)

The idea of drilling the spindle could work as a last resort. How big of a hole can I drill in a .625" spindle w/o weakening it too much? I don't have the owner's manual any more--does anyone have an idea on the spindle removal? Thanks to all--Mike.

yf
05-11-2003, 12:30 PM
Remove the spindle completely from the quill.
there should be a small shoulder for the lower bearing to seat against to take the thrust force when drilling. Then use your chuck wedges and spacers while applying heat.

If you disassemble and find no shoulder then hold the chuck in a vise and cobble up some attachment on the opposite end for a heavy slide hammer. Then heat the chuck and use the slide hammer to pull the spindle out of the chuck.

To prevent this from happening again you can do several things. A threaded jacking collar above the chuck. A pressed on washer to give a place to bear wedges against. A redesigned spindle. A new spindle can probably be made from a morse taper extension, by turning the male taper to fit the bearings. This will take up more space between the spindle and table but in imo is worth it.

mikem
05-11-2003, 03:30 PM
Thrud gets the gold star for the thermal expansion idea! I heated it up and wacked it with a hammer on a punch inserted into the key holes and it popped off! The only bad thing is it surprised me so that I didn't catch it and it hit the concrete floor. Now it has a little concrete bite mark to go with the other dings it already had.

George-- is the ring gear on the jacobs just pressed on? I will want to use this chuck for something again later and would like to use your suggestion to make the keys fit better.

Thanks to all. You are a great help to the aspiring metal head--mike.

yf
05-11-2003, 03:40 PM
BTW a JT33 is just the size for tapping 5/8-11 NC. Finish with a bottoming tap.
It will then go on your 4" angle grinder spindle and is really handy http://bbs.homeshopmachinist.net//smile.gif

Don't do it with a chuck with a sintered gear! it could explode from the high RPM!
Only do that with a solid machined steel chuck.
Before I mounted mine on the grinder, I put it in the lathe and took a cleanup cut on the outside of the chuck body to make sure it was concentric. It helps with balancing at 10,000 RPM.

docsteve66
05-11-2003, 05:24 PM
MikeM: I am suprised the thing has not dropped out. I did not mean to vibrate it out. I meant try milling with an end mill, the mill not bottomed out against its end. The down force might pull the taper out of its socket. Mark this up to "the innate perversity of inanimate objects (TIP of IA)". You want it to stay up it fall out, you want it out and it won't fall.

If the chuck unscrews, you may make a round collar, ID large eonugh to fit over the taper nose and small enough to shoulder out againt the chuck top. then screw the chuck into the collar. All you need is .0001 inch movement to let it drop free. This gives same effect as a wedge except the wedge is the screw thread pitch.

I am havingtrouble visualizing your situation, can you remove the chuck and leave the taper in the quill? Might be easier to remove the taper then.
Steve

mikem
05-11-2003, 05:44 PM
Hi Steve:
The chuck was stuck on the spindle with a #33 Jacobs taper. The spindle is solid(one piece) and I tried make the chuck fall off while milling sideways on a piece of 1/8" mild steel and couldn't get it to loosen. There was a fair amount of chattering but no loosening. I had milled with it before and it would never stay in!

Then, as Thrud suggested, I heated it up and and with a tap from my hammer, it fell off. The old grease started to boil out of the chuck when it got hot. The new Rohm is really nice but a bit stiff. There was no instruction sheet--how should I lube this to make it easier to operate? Thanks to all--Mike.

George Hodge
05-11-2003, 10:26 PM
Mike,yes the outer ring is pressed on,it binds onto a special split collar that has threads to mesh with the rack on the 3 jaws. The Jacobs Chuck site has good information about their chucks and most is applicable to other brands.

Thrud
05-11-2003, 11:01 PM
mikem:
Don't screw with the new chuck. It will loosen up a little with use. It is normal for a new keyless chuck to have more drag than a Jacobs - they are not as sloppy! http://bbs.homeshopmachinist.net//biggrin.gif

Take the burs (I knows you got 'em) off the shanks of your drills - you will not spin any drills in your new chuck when it is tightened properly - KEEP IT THAT WAY and clean up the scarred shanks of your drills!

You may want to clean up the JT33 before installing the new chuck if it has any surface imperfections.