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Morse Taper Removal

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Jim Greethead18/12/2011 21:13:07
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131 forum posts
8 photos
Hi Ian,
 
Your "spanner/hammer" might be the go, at least until I get sufficiently enthusiastic and build one based on an air hammer.
 
Pity about the little handwheel though. One side effect was that running the drawbar up and down was done with a flick of the handwheel instead of that tedious thumb & forefinger work (lazy? Too right I am). There wasn't much flywheel but it seems that the bit that worked here was the bit that loosened the drawbar.
 
I am still puzzled about the drawbar coming loose. As someone pointed out, the cutter load will tend to tighten the drawbar. The only thing I can think of is that I was using a profiling cutter which makes heavier interrupted cuts than an end mill. I think that the start of each cut slowed the motor just a bit (and tightened the drawbar) but then the motor accelerates again which tends to loosen the drawbar. I think the loosening effect is greater than the tightening effect.
 
Michael: Thanks for the photo. I think the air hammer one is the one I was thinking about.
 
And I am still thinking.
 
Merry Xmas to all of you and thanks again for the stimulating discussion.
 
Jim
 
Jon18/12/2011 22:05:34
1001 forum posts
49 photos
The cutter vertical load is imparting more pressure than force tightened and in turn reduce the grab on the spindle, in effect loosening.
Much like the impact wrench mentioned and same as using MT drills with tangs ie cannot revolve but can drop out the spindle if chattering - same thing.
Now try this, just tension up the drawbar finger tight and take a menial cut with a cutter in on something, if cutter dont drop you can hear the drawbar working loose.
For the MT to tighten it would have to revolve in the spindle MT and the drawbar to remain unmoved.
 
The cure is to tighten the drawbar past the point where upward forces are not exceeded, problem solved.
 
Must get round to fitting the butterfly air impact wrench some day, got all the stuff needed inc regulator, tubing etc.
Jim Greethead20/12/2011 06:42:00
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131 forum posts
8 photos
Jon: I am pleased to know that I am not the only one with small piles of all the necessary bits for things just waiting for me to decide that they are the next project. They usually wait until the current project has disheartened me or everything else looks too hard. Sometimes the piles get raided for things needed elsewhere of course.
 
Michael: What is "quill bounce"? When I googled it, I got a video of several children jumping on a trampoline plus a number of other suggestions that didn't look too much like a milling machine problem.
 
I am now back home after the usual Ho Ho Ho run to see family in Sydney so I can give some thought to Ian's "spanner/hammer".
 
Thanks to all for the continued interest
 
Jim
 
Jim Greethead20/12/2011 19:57:25
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131 forum posts
8 photos
Thanks for the explanation of "quill bounce" Michael, I have not previously heard it called that (or anything really) but I always lock every axis that I am not cutting along. Interested to learn that locking the quill does not cure the problem.
 
I guess these small things add up to make the difference between the surface finish I get on the HM45 and the one I got on the HAAS CNC machine in the course I did at Tech this year.
 
Now "orbital precession": could it be the axis of rotation of the quill wobbling like the axis of rotation of a spinning top? And if so, what order of magnitude of error does this cause?
 
Thanks for the continued interest and for exercising both remaining neurones.
 
Jim
 
Jon20/12/2011 22:12:31
1001 forum posts
49 photos
Quite right Michael, the bearing is in the quill and heads, any minute play even if Timken would induce vertical and lateral movement even though quill locked up. Minimal though.
Far greater movement is often experienced with poor build machines, you can visually see a Wabeco mill bounce and deflect on the upright column yet alone the head.
 
Right Jim pretty much same machine as mine, the geared head is very heavy hanging off a dovetail. Lock it up, put a cut on and you will see vibration/deflection originating from this joint, i grolly mine up and still see it. No visual or felt vibration or movement on upright dovetal column.
Another area due to the build is the quill in the casting fit, it will wear quick.
Precession then would cut oversize right angles to the torque.
 
Another for Michael and Jim is when tension is on the quill winding upwards, zero DRO and take a cut.
Now try winding down to zero with tension on, it will be something else.
If no play should come out the same. I dont get this off the spare RF25.
New decent quality bearings if anything too tight.
 
Found coolant pump today Jim, had it 7 years.
The CNC was probably better built and running a lot faster, the downside of the ZX40/45 series.
I am after the transfer box bolted to upright column between the elevation motor if you convert it.
 
Jim Greethead22/12/2011 07:18:14
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131 forum posts
8 photos
Ian (Berto) would you believe it? Today I went in search of a tube spanner to convert into a "spanner/hammer" but the cupboard was bare. Spanners smaller and larger were available but the rack holding the ones I need was empty. So maybe lots of others have been reading this forum and have beaten me to it. Or maybe not.
 
Thanks for the additional explanation Jon. It sounds like I am stuck with the limitations of the HM45 added to my own limitations. Just as well bog and paint are still available.
 
And then yesterday, I tried to counterbore a 1/8 inch hole using a 1/4 inch 3 flute end mill in the Jacobs chuck (yes, yes yes, but I had several holes to drill and counterbore). I am not sure if what I saw was "orbital precession" but the cutter seemed to be walking around the circumference of the hole. The counterbore measured 7mm.
 
I have yet to try the other combinations: using drill for counterbore (the bottom need not really be flat), use collet chuck for the 3 flute cutter and use 4 flute cutter in the Jacobs chuck.
 
I have certainly used milling cutters in the Jacobs chuck for counterboring before but usually, I am watching the depth of cut rather than the actual operation. But I am usually cutting aluminium (this was cast iron) and don't usually get oversize holes.
 
I just thought it was a bit of a coincidence after the discussion.
 
Jim
 
BERTO22/12/2011 09:43:50
46 forum posts
G'day Jim.
Yep 17mm is common !
Maybe if you had say some 40 or 50mm(1-5/8 or 2" for us metric haters !) roundbar or even square bar as it doesn't really matter then cut a length say 3 inches long (75mm ) and tap a hole in one end you can screw on an endcap made from brass or lead then tap another hole mid way along its length at 90 degree to the axis , this is for the handle .
On the other end simply mill a slot to fit the head of the drawbar and by doing this you have created an open end spanner / wrench .
After todays play in the shed in which i must have changed between a boring head ,a collet chuck and a drill chuck at least 20 times i will be making something similar very soon !
Everytime you want the spanner it is never at hand and the hammer- well it just seems to find its own place to hide !
Another thing i am thinking is to use to hoop type hammer holder that a builder / carpenter uses on thier belt and fit something similar to the side if my mill so when i use the hammer / spanner unit i can simply slot it back into its holder that way i have both tools at my fingertips when i want them !
 
Also oddly enough i was using a 1/2 inch end mill to counterbore 2 x 5-1/6 holes in black steel , the first had no issues but on the second i got some chatter so i stopped and checked things over and i had not tightened the locks on the head / column dovetail .
I was using a collet chuck though as i will not even think of sticking a milling cutter of any kind in a jacobs chuck as they are not rigid enough in any way and the tooling is too expensive to replace .
I usually end up setting up my ER32 chuck and have the correct collets, drills and counterbores ready in sequence so i can drill , clearance then counterbore each hole then move on , it does go reasonably quickly once you get into a rhythm.
I have the same machine as you (HM45/46)and have had no problems so far but maybe you could check the gib adjustments and keep the spindle as far up in the head as possible when machining as any play in the spindle housing bore is is magnified the further the spindle projects from the head .
 
Regards..
 
Ian
Jon22/12/2011 10:22:28
1001 forum posts
49 photos
Jim bet the cutter was knackered. I do similar most days and drill through 16mm as many as 144 holes on chamfers with three flute 3mm to 6mm in a chinese freebie chuck.
Quite a few 4 flute are not centre cutting and leave a pip.
I must stress this, you have to get the feel for whats happening rather than force.
 
The only real limitation on my 45 is top speed of 1250 rpm.
Several mods have to be done enabling larger bearings.
Jim Greethead22/12/2011 10:43:12
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131 forum posts
8 photos
Ian: The spanner I needed was 13/16" ( and you reckon metric is weird) and I was after a tube spanner because I have a cunning plan. I would still like to have the spanner and hammer on the drawbar but to avoid the problems associated with the moment of inertia. So ... I am thinking of putting a spring under the spanner so it is not locked to the drawbar and then incorporating a heavy handwheel that can tap out the tool.
 
And if that does not work, I will cut the tube spanner in half and put the hammer on the other end and a handle in the middle.
 
And if none of that works, keeping it in a loop in the vicinity sounds good.
 
And yes, I am aware of the limitations of the Jacobs chuck and would never (well hardly ever) apply radial loads to it. But for counterbores, it is just acting in the drilling mode so I thought it would be alright. I must admit that I had not considered your scheme of setting up the various tools in their collets but it makes sense and is probably no more time-consuming than using the Jacobs chuck. Thanks for the tip. And for the other suggestions.
 
Jon: I must check the cutter. It is relatively new and has not done any serious work. It is not a Dormer but I think it came from a reputable source.
 
Thanks for the continued discussion
 
Jim
 
Jon22/12/2011 11:21:13
1001 forum posts
49 photos
Its the tool quality that counts i have a new 10.5mm Titex Plus two flute that has only drilled 12 holes in 6082, that started going after a few holes 12mm deep with already 5/16" holes through.
I love them cheap long Hertel JL3 disposables up to 6mm.
 
I hate to think how long it takes to undo, remove the ER collet, clip it out, clip new back in, locate thread and tighten each time with two spanners.
Quick fail safe route a decent quick release drill chuck have drills and taps laid out 5 to 10 secs to change hand tight - every one a gem whats all the fuss about.
Now i am sure you are fully aware of the precession of using such extended collets amplifying any runouts and stressing the bearings a lot more.
While i dont advocate milling with a drill chuck, i do it all the time and to good effect. Its only when a long winded job is on requiring precision stuff i will change over to collets. Plus its knowing what the tools will take rather than the big ooooh no mustnt do that attitudes.
 
Ian S C22/12/2011 12:12:10
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7468 forum posts
230 photos
My method is to drill hole, start counter bore with normal drill,then finish it with either an end mill, or a D bit,that way I get the c/bore the right size and concentric.
Ian S C
Jim Greethead24/12/2011 21:31:39
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131 forum posts
8 photos
Sounds a bit long-winded Michael: use spanner to loosen the drawbar a bit, pull down (or fit) the lever, move lever out of the way, unscrew drawbar.
 
Certainly, it eliminates the "whack" but after the foregoing posts, I wonder if that is a problem.
 
Now if you attached an air hammer to the lever ...
 
It is Xmas - must go and check if Santa has left any goodies in the workshop.
 
'Ave a good one, all of you
 
Jim
Michael Gilligan24/12/2011 22:34:36
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23121 forum posts
1360 photos

This won't help those who have Morse Tapers on their milling machines, but:

The "correct" taper for the Mill is not self-locking. There are variations on the theme, but they are all much steeper than Morse, and therefore require only a light tap on the drawbar, to release them.

Edited By Michael Gilligan on 24/12/2011 22:41:25

Terryd25/12/2011 07:20:33
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1946 forum posts
179 photos
Hi Jim,
 
I just use a lead or copper hammer, loosen the drawbar by half a turn and give a solid, 'dead' thud on the top of the drawbar, more of a hefty push really, difficult to describe but easy to demonstrate. If you have to use a ruddy great lump hammer, the problem is caused by over tightening the draw bar and hence the Morse taper in the first place. I can't remember ever having a taper tool come loose (I have had collets and chucks do that in the mill due to the intermittent shock loading inherent in the milling process) and I have never used a great deal of force when tightening. There are far too many gorillas in machine shops already.
 
By the way, never use any lubrication on a Morse taper. They work by friction and lubrication is intended to overcome friction, just keep the mating parts clean and ding free! Nuff said?
 
Happy Yuletide ,
 
Terry
Jim Greethead25/12/2011 08:58:49
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131 forum posts
8 photos
That sounds about right Terry, it is really just a drop of an inch or two under gravity with the lump hammer. I could use a lead or copper hammer but I don't have one and probably don't need one for this job.
 
Everything clean and definitely no lubrication.
 
'Ave a good one.
 
Jim
 
David Caunt24/01/2020 22:42:25
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110 forum posts
40 photos

Hope this modified stolen pic shows how I got round the problem.

drawbar technique.jpg

Dave

Anthony Knights25/01/2020 11:32:07
681 forum posts
260 photos

You could always make something similar to this **LINK**

BOB BLACKSHAW25/01/2020 11:50:46
501 forum posts
132 photos

Works on my  SX2p.

Bob dscn0950.jpgSX2pW

Edited By BOB BLACKSHAW on 25/01/2020 11:53:11

Howard Lewis25/01/2020 15:33:03
7227 forum posts
21 photos

For my elderly Mill/DRill, I removed the Left hand Threadede nut that holds the pulley to spindle. Turned back 1/8"

Took a piece of 1/8" steel, plate and bored a hole in nthe centre, to just fit over the nut.

Tapped two holes about the centreline. (1/4 BSF in my case )

Replaced the nut with the plate under it.

Took a similar piece of plate, drilled two 1/4 clearance holes on the same centres as the tapped holes.

Drilled and tapped a 1/4 BSF hole in the cemtre.

Fitted a long 1/4 BSF setscrew to the tapped hole, and two 1/4 BSF setscrews, of a suitable length, through the clearance holes..

When the time comes to remove 3MT tooling from the quill, slacken the Drawbar about a turn.

Screw the two 1/4 BSF setscrews into the plate, and tighten the central 1/4 BSF setscrew onto the top of the drawbar, and tighten. This should push the drawbar, and the tooling from the taper.

If, with the central screw really tight, the taper does not "break", a tap with a light hammer will do the trick.

This should subject the bearings to no or little force when removing tooling.

Howard

larry phelan 125/01/2020 19:20:54
1346 forum posts
15 photos

I always give the drawbar a little help with the aid of a piece of lead filled copper pipe 1" dia.

On another note, yesterday I drilled 25mm from the tailstock [ in stages ] without anything slipping.

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