Need Help!- XJ12 How to remove the Taper Shank

[rnr107]

Hi all,
I have a small mill XJ12-300 (a bit similar to the SIEG X2) and as most small mill it came with a drill chuck... I am trying to replace it with a milling chuck.

I follow the basic instructions in the manual:
Loose the draw bar, knock gently with a ruber mallet the draw bar to loose the taper shank from the spindle sleeve...

Now, the draw bar is loose, I knock as much as I could without damaging anything but nothing move...

Is there anything else that needs un-tighten? or am I doing something stupid?

Thank you,
RNR

[packrat]

If it's been in there a while a rubber hammer won't do it, never heard of using a rubber hammer any way. Use a brass hammer, you need to shock it if it's been there awhile.
Make sure the drawbar is screwed in to the chuck and not free floating, or you'll mess up the threads.

cary

[rnr107]

Hi packrat,
By hammering the draw bar, am I not going to damage the Z axes? should it be lock or loose?
I don't have any brass hammer, but I guess I can find a piece of brass rod and make one...

Ta,
RNR

[M250cnc]

RNR

A good piece of kit to get is a copper hide mallet, this will be useful for this purpose also bringing your work down onto parallels when clamping in a vice.

You could get one on ebay.

Re the drawbar you need to unscrew one turn so you can see a gap and then a gentle tap with the copper end will loosen the chuck

You know when you have done it as the gap will disappear

This can be a big drawback if the machine has a tilting head as it can go out of tram

Phil

[rnr107]

Hi M250cnc,
Thank you for your help :-) I will get a copper hide mallet then...
But does this mean every time I need to drill I will have to hammer the draw bar?
Or can I use the collet holder to hold drill bits?
Also, the draw bar on this machine is threaded M12, so instead of hammering the draw bar, could I replace it with a piece of M12 treaded bar for this hammering operation?
(I really don't like the idea of hammering a good working machine...)

Ta,
RNR

[M250cnc]

RNR

Fraid so, drilling is not so bad as you can use a drill chuck.

For milling you can use an er type collet chuck.

I just converted my mill spindle to R8 for this very reason also adapted the collect system to use a TTS type system.

An alternative is to have a parallel arbor for the drill chuck and then you can hold it in the er chuck but this will eat up your Z height.

Phil

[rnr107]

M250cnc,
On R8 spindle, there is no need to hammer the draw bar?
If so, that could be an option... the mill I have comes buy default with an MT3 but there is an option to get an R8.

Ta,
RNR

[packrat]

You need to give it a tap on the end of the drawbar. they are made to do this, it's not being cruel to it the Morse taper will take more force than the R8 to dislodge it, just because the taper is longer and shallower.

You don't need to use a sledge hammer type blow just a mild crack.

The harder you tightened it up originally the harder you will have to crack it to loosen it. It's basically a acquired skill to learn the amount of force to use, bot tightening and tapping to remove.

[M250cnc]

RNR

The best option is an R8 taper, a light tap with the drawbar ring spanner is all that's required to loosen the taper.

Phil

[rnr107]

M250cnc, packrat,
Thank you for your time and advices! I finally got it out!
I just had to hammer a bit longer...

But, it looks like an R8 conversion would be the way forward.

RNR

[packrat]

The Morse taper is the Old School way of doing mills. Back in my high school days(1966)
the machine shop class had end mills with Morse taper shanks.

The R8 will open up the number of different tools and holders you can use.

cary

[rnr107]

R8 is the future! ;-)