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Re: HF 5980 3 in 1 Mill Chuck Stuck

Posted: Mon Nov 28, 2011 3:10 pm
by BentTooner
Hi,

Ok, got it about NOT spreading the slot.

I've made a new wedge that increases size in the vertical direction and it's still not moving the tool holder/chuck at all. Because of the way the wedge enters the slot, one side of the slot is NOT pushing on anything while the other side makes contact. So, I've tried putting the wedge in from each side to try to move things equally. But still no luck...

I suspect the piece has "welded" in place by corrosion. Also, maybe side loads from the prior owner milling with the chuck (rather than drilling) have caused some problem. It's hard for me know what's going on because I cannot see what's in there...

I'm imagining the chuck has a straight (non-tapered) shaft and the 'drill taper stock' is a hollow tube with a taper like a spring collet on my Dremel tool. I'm imagining that the chuck's shaft slides inside the hollow tube and then the tube and chuck slide up, into the quill's hole. Then, the draw bar threads into the top of chuck (it doesn't look as if the draw bar threads into the tube) and pulls the chuck up, farther into the taper of the quill. I'm guessing the taper squeezes the sides of the tube to grip the straight shaft on the chuck. Do I have that right?

I'm thinking the problem is that the tube is stuck in the quill and so the chuck's shaft is stuck in the tube. Even if I got the chuck out, the tube would still be stuck in the quill.

Again, thanks for all the advice!

Re: HF 5980 3 in 1 Mill Chuck Stuck

Posted: Mon Nov 28, 2011 5:26 pm
by Torch
BentTooner wrote:I'm imagining the chuck has a straight (non-tapered) shaft and the 'drill taper stock' is a hollow tube with a taper like a spring collet on my Dremel tool. I'm imagining that the chuck's shaft slides inside the hollow tube and then the tube and chuck slide up, into the quill's hole. Then, the draw bar threads into the top of chuck (it doesn't look as if the draw bar threads into the tube) and pulls the chuck up, farther into the taper of the quill. I'm guessing the taper squeezes the sides of the tube to grip the straight shaft on the chuck. Do I have that right?
The "drill taper" is a solid chunk of steel (well, except for the tapped hole on top for the draw bolt). It is tapered on both ends. The upper end is a "Morse Taper" (approx. 5/8" per foot, etc.) and the bottom end is also tapered, probably a "Jacob's Taper", since most drill chucks are sized to fit a JT standard taper.

Have a look at this web page. It's got lots of pictures which might help you visualize what's going on and what you need to do.

Re: HF 5980 3 in 1 Mill Chuck Stuck

Posted: Mon Nov 28, 2011 6:16 pm
by BentTooner
Hi,

Thanks for the link.

I got it out! I saw a good picture of the 'tool wedge' on one of the posts on this site for this machine and then it clicked for me. So, I made a new wedge from 1/4" plate aluminum and, while it took some serious power, the chuck finally broke free. It chewed up the aluminum wedge up a bit but I would rather have the wedge damaged than the machine.

It doesn't have any corrosion on it so I'm not sure why it was stuck so hard. Anyway, I took some pictures.

Here's the chuck:
MillDrillChuck1.gif
MT2 Mill Chuck
Here's a couple of pix of the tool wedge:
ToolWedge1.gif
Tool Wedge
5" long
1 5/8" tapering to 5/8"
1/4" plate aluminum
Rounded edges
ToolWedge2.gif
Another angle on tool wedge
Again, thanks so much for hanging in there with me!! It was a big help!!

Now I can start working on a new drawbar to hold the SAE threaded end mill holders...

Re: HF 5980 3 in 1 Mill Chuck Stuck

Posted: Mon Nov 28, 2011 8:38 pm
by Torch
BentTooner wrote:I got it out!
:D :D :D :D :D :D
while it took some serious power, the chuck finally broke free. It chewed up the aluminum wedge up a bit but I would rather have the wedge damaged than the machine.

It doesn't have any corrosion on it so I'm not sure why it was stuck so hard.
Yup. They do that. The Morse Taper is a long shallow taper friction fit, designed to withstand a fair bit of torque. There's a lot of stiction there! It's also possible that the spindle was warm but the chuck was cold the last time it was installed. Add a big boy with a long wrench...
Again, thanks so much for hanging in there with me!! It was a big help!!
Less than 2 years ago, I was the newbie and guys like Harold and Glenn and Steve and Bill and, well, all the others, "hung in there" for me. It's kind of fun to finally be able to help someone for a change :lol:

Re: HF 5980 3 in 1 Mill Chuck Stuck

Posted: Thu Dec 01, 2011 7:22 pm
by mac.doogle
Mine was stuck the same way, If this helps I had to use a tie rod knocker to get it loose. It worked fine and did not damage anything. Leave some of the drawbar screwed in some. It worked for me.

Re: HF 5980 3 in 1 Mill Chuck Stuck

Posted: Fri Dec 02, 2011 9:16 am
by BentTooner
MacD

Thanks for the great ideas. I have a tie rod pickle. I'll check it out. Also, that's a great tip to keep the draw bar threaded a bit so the chuck can't drop out.

Thanks again to all!