The Home Machinist!

Hi, all

I am new to machining and to this web site. I recently got a used Harbor Freight 3 in 1 model 5980. The mill has a Jacobs chuck in the quill head and I've read that one should not mill with a drill chuck. I understand it's better to use a tool holder such as a collet for the end mill.

I read the manual and it says to strike the drawbar with a hammer to release the chuck. I have tried this and the chuck is not moving. I'm afraid to strike it too hard for fear of damaging threads, bearings, etc. I've added penetrating oil from the top and bottom to try to loosen it up but it's not moving at all.

Does anyone have any tips for getting the chuck out? For example, would it be safe to use some kind of spreader at the chuck end?

Thanks!

Did you back off the drawbar first? (Just a couple turns---and it should be a right hand thread. No, I'm not trying to be a wise guy ). Once it breaks loose, you should be able to twist the drawbar out effortlessly.


That's likely to remove the chuck from its shank, which isn't your objective.

Welcome to the forum.

Harold

_________________
Wise people talk because they have something to say. Fools talk because they have to say something.

I gather there a draw bolt on top of the spindle? Did you loosen the draw bolt a few turns first before hitting it? There should be a visible gap between the bolt head and the top of the spindle before hitting the bolt head.

The machine probably has an R8 spindle taper. This does grab tightly, but normally releases completely with a sharp rap. I usually use the handle of the wrench in my hand -- one or two whacks and Pop!. That said, the R8 format can have a key that is supposed to keep things from rotating while tightening the draw bolt. If the bolt was not sufficiently tightened to draw the taper tight and then it spun under load, you may have the key jamming things in place. If that is the case you can either wail away at things and risk further damage, or remove the spindle and see if you can drill out the remains of the key. Failing that, have a shop mill out the jacob's chuck adapter after removing the chuck. The adapters are fairly cheap.

There was a recent thread around here about the merits of the key. I personally am on the side of deleting the key. There's enough friction in the R8 taper to keep things from spinning while the bolt is being tightened.

A spreader will likely just pop the chuck off the JT end of the adapter.

EDIT: I see Harold beat me to it. Again.

Hi,

I replied earlier but it's not showing up so I thought I would try again.

Thanks for the replies! I did back the draw bar out a bit and then whacked it. (The draw bar comes out and goes in with no problems.) It didn't matter. The chuck didn't move at all.

I was thinking of getting a plain bar the same diameter as the draw bar and whacking on it so I don't damage the threads. Would that hurt the chuck holder?

Thanks a lot!

One of the possibilities is the chuck may be held in a collet, with a straight shank. Might be a good idea to place a piece of wood under the chuck while you're messing with it, trying to get it out. That may prevent a ding in the table.

Don't use anything but the drawbar. If you wish to ignore that admonition, use a piece of aluminum round bar stock, as large as you can insert, so you don't drive it in to the threads of the adapter/collet.

The length of engagement with draw bars is quite long, so as long as you loosen it just a couple turns, you should be able to wail on it far greater than you should and not damage the threads. That's really the last of your worries.

Can you take a picture of your machine? Maybe a close-up of the spindle/chuck area, and the top, where you loosen the drawbar? These things aren't usually a problem being removed, so something appears to be wrong. Maybe we can see something that will be helpful.

Harold

_________________
Wise people talk because they have something to say. Fools talk because they have to say something.

Hi,

Thanks again for the help.

Yes, I will take pictures today and post them.

I'll be more forceful with the hammer today, too. I was hoping the penetrating oil would eventually help ease the chuck out.

The manual refers to a "drill taper stock" under the "9. Accessory Table" section on page 12. That section also refers to a "Drilling chuck - JS16". I'm not sure exactly how the drill chuck is held in the mill head. I don't know what a 'drill taper stock' is (but I'm guessing it's some kind of tool holder for the milling head) and I don't know what "JS16" means, either.

Anyway, I'll post more soon. Thanks again!!

I've never heard of a "JS16" taper, so I downloaded the manual on-line and see the reference. I wonder if that is the model number of the chuck itself?

I also note that the milling spindle is listed as having an MT-2 taper! There should be a wedge with the machine and a slot in the quill. Lower the quill until the slot is exposed. Rotate the spindle slowly by hand until you see a corresponding slot in the spindle align with the quill slot. Inside you should be able to see the top of the chuck adapter. Remove the draw bolt and insert the wedge through the slot above the adapter. Hit the wedge with a hammer to release the adapter. MT tapers grip much tighter than R8 (they are longer and shallower) and may need a little more oomph to release.

Hi, Torch

Thanks! Yes, I think I see what you're saying. I don't have the wedge piece but I think I saw a picture of a wedge somewhere (maybe in the manual from the Northern Tool version of this machine, which manual is MUCH more detailed than the HF manual). I can cobble something to make a wedge...

So, (I'm slow...) if I follow:

1) Lower the quill all the way by turning the quick-change handles clockwise and lock it down.
2) Find the slot in the quill.
3) Spin the spindle by hand until the slot in the spindle aligns with the slot in the quill.
4) Locate the top of the chuck adapter.
5) Remove the draw bolt.
6) Insert a wedge in the slots so it is above the chuck adapter.
7) Put something under the chuck to protect it and the lathe bed if/when it falls out.
Strike the wedge with a hammer.

I'm guessing the idea is the wedge spreads the inner slot (whatever that is) to increase the diameter of whatever the slot is cut in, in order to relieve the compression on the chuck adapter, right?

Thanks again, very much for all the help!

Hi, again

The chuck is still stuck...

I lowered the quill, found the slots and tapped a wedge in but it didn't move the chuck. There's VERY little difference between the outer slot and the inner slot that you need to spread so I'm not sure I'm doing much with the wedge.

I also loosened the draw bar, whacked it with a piece of wood and a sledge hammer, to no avail. I've squirted a lot of penetrating oil into the head and I'm hoping it will eventually loosen something up.

I took some pictures, which I've attached.

The 1st pic shows the draw bar and the slots.



The 2nd pic shows the top of the machine where the draw bar inserts.



The last picture shows a page from the manual. #8 is called the 'drill taper slot" and #5 is the wedge.



I don't have the wedge (so I made one) or the drill taper stock. I'm wondering if the drill taper slot is holding the chuck in the quill...

Yes, the "drill taper" is male MT-2 on one end and probably one of the JT tapers on the other (my guess would be a JT-6 or JT-33 by the picture). The chuck will have the corresponding female JT taper to fit over the adapter and is a friction fit. That's why you can't safely use it for milling -- side loading and any vibration tends to loosen it.

You can just see the top of it through the slots in your picture. The wedge pushes down on that, against the top of the slot. It will need a hammer!

Hi,

Hmmm. I'm thinking maybe I don't understand how to properly use the wedge. I was trying to spread open the slot with the wedge. I was inserting the wedge so it got wider in the horizontal plane. But, is that right?

You say the wedge works "against the top of the slot", is that right? Does that mean the wedge should fill the height of slot and gradually push against the top of the chuck/adapter RATHER than using the wedge to try to spread open the slot? In other words, the wedge should work in the VERTICAL plane to push down on the top of the chuck???

Thanks so much!!

DON'T TRY TO SPREAD THE SLOT!!! You'll only cause damage, if anything. You absolutely want the wedge vertical, so it pushes down on the top of the adapter. Put the straight edge of the wedge against the top of the slot and the tapered edge of the wedge against the top of the adapter, then hit the wedge in with a hammer (dead-blow hammer if you have one).