Morse Taper Tool Extractor

[Oldneweng]

A project I have been thinking about and designing. :C

Kryn sent me designs for a wedge type extractor that works between the bottom of the spindle and the tool head etc. The problem with this is that the tool needs a step for the wedges to locate against, below the spindle. A tapered drill does not have such a step and there is a fair amount of variation between tools and I have only looked at 2 or 3.

I am thinking about a tool that goes into the taper extraction (drift) slot. :?

359504

Arms at top and bottom pivot on pins to right. The block on the right has slots to take the arms. An 8mm hole is drilled thru it left to right. The round item represents a type of wedge. I am still thinking about the best shape. Maybe a wedge shape with rounded front (narrow end) corners. A cross between the round, and the wedge I drew originally. The hatched area is an M8 threaded hole. A bolt passes thru the block on the right and screws into the wedge (circle) drawing it in and spreading the arms. The arms are shown in the open position above. I would like to have a radius on the outer arm surfaces where they contact the taper slot radii, if I can work out how to do it. I could use the rotary table, but this would be fiddly.:o

The extrusion on the bottom arm is a result of the drill chuck that came with the mill not quite reaching the slot by about 2mm. I still need to look at all the other tools to see what the final size/design should be. It is currently the full height of the slot as pictured above. The bolt will probably be a screw like a clamp uses with a tommy bar permanently fitted.:rolleyes:

Questions for the brains trust. :-

What would be the best shape for the wedge?
How to machine radii on the arm outer surfaces to fit the extraction slot.

Any other suggestions/issues you can think of. :doh:

I am thinking of hardening and tempering the arms. They will be made from mild steel at the moment. Maybe I can find something better later. I will heat them in contact with carbon, enclosed (pipe with end caps). Reheat to red hot and quench then temper. I have seen this method on the net and I would like to try it.

Here is a pic of the closed position.

359507


Dean

[jhovel]

Looks complicated.... I bought one of these (but on eBay) for about $20.... works very well. One jand movement and its out.

[Michael G]

I did it this way, but this relies on the quill being able to retract and so push the taper out.
359508 359509

Michael

[KBs PensNmore]

Looks complicated.... I bought one of these (but on eBay) for about $20.... works very well. One jand movement and its out.

Hi Joe, unfortunately "one of these" doesn't tell me a great deal, any chance of a pic please.:D

[Oldneweng]

I did it this way, but this relies on the quill being able to retract and so push the taper out.
359508 359509

Michael

Hmm. That would work for me, I think. I will have to check tomorrow. Would be easier to make. All part of the design and development process. :D

Joe.

I also would like a picture and maybe a name to enable an EBay search. Just had a look and found nothing but drifts.

Dean

ps Seeing the drifts made me realise that I should get some halfway decent ones. The only one I have is a POS that came with my drill press. It looks rough and is not hard, nor are the edges radiused.

[Ueee]

I don't think you really want them hard. I'd rather have to make/buy a new drift every 12 months than damage the tang of the tooling or worse the slot in the spindle.

To be honest Dean i have no idea how your 2 armed wedge is supposed to be used. Just can't picture it.

[KBs PensNmore]

I think, what Deans drawing is missing , is a bolt that screws in the hole between the 2 arms, as it screws in, the arms are forced apart pushing out the tang and bit.
Kryn

[jhovel]

Oops, sorry.... somehow the link disappeared.....
I bought mine on eBay as mentioned, but I can't find a link to one there either today....
At least here is a picture.
Semi-Automatic Extractor Tool for Morse Taper MK4-MK6: Amazon.co.uk: DIY & Tools (http://www.amazon.co.uk/Semi-Automatic-Extractor-Morse-Taper-MK4-MK6/dp/B005NGEZVQ)
This might even explain better how it works:
http://www.acy.com.sg/index.php?main_page=product_info&cPath=259_609_673&products_id=5581

[Oldneweng]

I think, what Deans drawing is missing , is a bolt that screws in the hole between the 2 arms, as it screws in, the arms are forced apart pushing out the tang and bit.
Kryn

Exactly. The bolt would have been too confusing, to me at least.

I did mention it. "A bolt passes thru the block on the right and screws into the wedge (circle) drawing it in and spreading the arms."

This spreading of the arms pushes against the top of the spindle slot and the top of the tool taper, breaking the taper lock.


I don't think you really want them hard. I'd rather have to make/buy a new drift every 12 months than damage the tang of the tooling or worse the slot in the spindle.

I am not talking about super hard. More tough. I am looking at a couple of different sizes on EBay at the moment. The description says

"Drop forged from specially drawn medium carbon steel
Accurately hardened for increased resistance to wear"

Hard is not what I want.

Joe,

Thanks for the picture. I saw one like that on EBay I think. It would not work if the tool taper does not extend into the slot, hence the protrusion on the bottom arm on my design.

Yep. Here it is.

http://i.ebayimg.com/00/s/MTAyNFgxMzYw/z/K78AAOSw-W5UxXH9/$_57.JPG

There were some nice looking drifts from Germany for only 5 bucks. Shame about the $150.00 postage. :o

Dean

[Anorak Bob]

Dean,

Couldn't you simply drop in a small cylindrical or spherical spacer above your short arbors to facilitate their removal with a conventional drift or a whizzo version like the Tangmaster?

BT

[welder]

I am with Bob on this one. If your tools are short put.a bolt. On the end or drop a nut on top and.use a drift. I have a mt removal tool from sweden a little better design then the ones pictured.

[Oldneweng]

There is not much room to fit anything inside the slot. It would need to go in on its side and then lay flat. Only 11mm slot and quite deep inside a 70mm quill. I want something that is quick and simple. I cannot screw in a bolt. Where would the drawbar screw in?

Dean

[.RC.]

I am surprised that tool will shift them, mine usually get well stuck that I need a decent hammer.

[jhovel]

These tools shift them VERY easily because they consist of two very slender wedges. the top one is pushed in above the bottom one with a cam arrangement with HUGE force. I have never had any trouble removing a really stuck chuck with mine.

Dean, previous posters weren't suggesting a draw bar, but to drop a loose nut into the slot on top of the Morse taper tang, for the extractor or wedge to push against.
It seems to me that you should probably mill the slot a little longer (towards the tool end) so you can insert 'normal' Morse Taper extractor tooling - wedge and hammer or semi-automatic extractor. The distance inside the qquill is no problem witht he too I showed you, the wedges are quite long.

[pipeclay]

If these tapers are short of the slot due to a draw bar retaining the taper why not just use the draw bar to remove the tool, as would be normal practice.

[.RC.]

These tools shift them VERY easily because they consist of two very slender wedges. the top one is pushed in above the bottom one with a cam arrangement with HUGE force.


ahhh that makes sense, looking at the picture I just thought it was a single wedge with a handle on it.

[Oldneweng]

These tools shift them VERY easily because they consist of two very slender wedges. the top one is pushed in above the bottom one with a cam arrangement with HUGE force. I have never had any trouble removing a really stuck chuck with mine.

Dean, previous posters weren't suggesting a draw bar, but to drop a loose nut into the slot on top of the Morse taper tang, for the extractor or wedge to push against.
It seems to me that you should probably mill the slot a little longer (towards the tool end) so you can insert 'normal' Morse Taper extractor tooling - wedge and hammer or semi-automatic extractor. The distance inside the qquill is no problem witht he too I showed you, the wedges are quite long.

I know what they were suggesting Joe. I don't want to mess around like that. I want a simple tool that will work even in that situation. The drawbar mentioned was the one locking the tool in place prior to removing it.

The main use for this tool is removing MT4 taper tooling from the mill spindle. Changing the length of the slot is not feasible.



If these tapers are short of the slot due to a draw bar retaining the taper why not just use the draw bar to remove the tool, as would be normal practice.

Pipeclay. It was to avoid doing this, that was the reason for coming up with this idea. To avoid damage to the spindle bearings from the hammering on top of the drawbar.

Dean

[RayG]

Pipeclay. It was to avoid doing this, that was the reason for coming up with this idea. To avoid damage to the spindle bearings from the hammering on top of the drawbar.

Dean

Interesting, with NT30 I just back off 1/2 turn and hit the draw bar with a light tap, I doubt that would ever damage the spindle bearings, how hard do you have to whack an MT4 to release it?

Ray

[Ueee]

Remember Ray, NT30 is a self releasing 8(?) deg taper, MT4 is a locking taper. Bottom lne is though if it doesnt not come out with a light tap it was probably done up too tight.

[Oldneweng]

They can tighten in place requiring more effort to release.

Dean

[jhovel]

Ah, now in understand and I'm 'with the program'.
My MT4 in the horizontal mill takes a HUGE hammer to loosen. It tightens in use and if it isn't tight, the tool spins. I also hate hitting the bearings! I was even contemplating boring the spindle to NT40 (which works just around MT4).

The other option is a special drawbar with differential threads to remove the tool without hitting anything. A self-ejecting drawbar.
It requires the far end of the spindle to be internally threaded with a finer thread than the drawbar-tool thread and a matching thread (obviously larger than the rest of the drawbar), as well as a fixed hex end to be fitted to the drawbar. By loosening the drawbar, the thread DIFFERENCE pushes the tool out of the taper. Tightening the drawbar tightens the tool as usual - by the reverse difference of the threads. For different tools you may need different washers to compensate for the change in geometry.
If you or anyone else needs a sketch, I'd be happy to oblige.

[Oldneweng]

I understand how it works Joe. In my case it may be difficult because I use 3 drawbars with different threads so I need to change them all the time.

I am going to try Michael's idea first. If that doesn't work I will look at something else, but I cannot imagine it won't work.

When I get time that is. I have been fencing. Half our property has a hole out to freedom. We had strainer posts replaced in 2 corners, now I have to put the box sets back up and reattach the fences. Thats the urgent work. There were also 4 other strainers replaced which need reattachment of fence or a new fence put up.

Dean

[steamingbill]

The other option is a special drawbar with differential threads to remove the tool without hitting anything. A self-ejecting drawbar.
It requires the far end of the spindle to be internally threaded with a finer thread than the drawbar-tool thread and a matching thread (obviously larger than the rest of the drawbar), as well as a fixed hex end to be fitted to the drawbar. By loosening the drawbar, the thread DIFFERENCE pushes the tool out of the taper. Tightening the drawbar tightens the tool as usual - by the reverse difference of the threads. For different tools you may need different washers to compensate for the change in geometry.
If you or anyone else needs a sketch, I'd be happy to oblige.


Brilliant !

Thankyou thats clever.

Bill

[jhovel]

Bill, I didn't invent this, just tried it and tried to explain it.
I think it's brilliant too.

[Oldneweng]

I understand how it works Joe. In my case it may be difficult because I use 3 drawbars with different threads so I need to change them all the time.

I am going to try Michael's idea first. If that doesn't work I will look at something else, but I cannot imagine it won't work.

When I get time that is. I have been fencing. Half our property has a hole out to freedom. We had strainer posts replaced in 2 corners, now I have to put the box sets back up and reattach the fences. Thats the urgent work. There were also 4 other strainers replaced which need reattachment of fence or a new fence put up.

Dean

I simulated Michael's idea, but I found that it also applied the impact to the spindle bearings. The way it works is that the quill is lowered so the extraction tool (in my case an ER40 collet chuck spanner:rolleyes:) fits in the slot, resting on top of the taper section of the tool. Remember this is a drawbar secured taper. The quill is then forced up by the handle(s) until the extraction tool hits the bottom of the mill head applying an impact to the taper tool, releasing it. I found it took quite a bit of impact force to release. The impact passes thru the bearings from spindle to quill/mill head.

http://metalworkforums.com/attachment.php?attachmentid=359508&d=1441187409&thumb=1

I am thinking it is back to my original idea. Won't hurt to try it anyway.

Dean

[jhovel]

It won't hurt to try.
Plan B might be making several self-releasing drawbars....
:)

[Michael G]

...The quill is then forced up by the handle(s) until the extraction tool hits the bottom of the mill head applying an impact to the taper tool, releasing it. I found it took quite a bit of impact force to release. The impact passes thru the bearings from spindle to quill/mill head.

Unless the bearings are directly exposed on the bottom of the mill head and the extraction tool is resting against them I'm not sure that is the case. With most of these milling heads the bearings are on an outer sleeve and the quill slides in this, transmitting power via a spline or key. With something like this there will be force applied to the bottom of the mill castings and to the rack and pinion but not to the bearings I would have thought.

Michael

[Oldneweng]

Unless the bearings are directly exposed on the bottom of the mill head and the extraction tool is resting against them I'm not sure that is the case. With most of these milling heads the bearings are on an outer sleeve and the quill slides in this, transmitting power via a spline or key. With something like this there will be force applied to the bottom of the mill castings and to the rack and pinion but not to the bearings I would have thought.

Michael


The quill slides up and down in a bore in the head. The bearings mount inside the quill with the spindle inside these. The force goes from handle to gear to rack (quill) to bearings to spindle to extraction tool to head casting. The bearings are in the middle. As I replaced them not too long ago I have no desire to repeat the expense.

Edit: I should mention that I am having to use force on the handle. The spring return does nothing. The spring does need tensioning up a bit, but I don't think this will change much. I tried just nipping a tool in by light hand force and there was still no chance of the spring doing anything. The amount of force required to release the tool is far more.



It won't hurt to try.
Plan B might be making several self-releasing drawbars....
:)

It is not entirely out of the question.


It requires the far end of the spindle to be internally threaded with a finer thread than the drawbar-tool thread and a matching thread (obviously larger than the rest of the drawbar), as well as a fixed hex end to be fitted to the drawbar.

This far end you mention, I presume is at the top of the spindle in the case of a vertical mill like mine?


For different tools you may need different washers to compensate for the change in geometry.

I checked yesterday and found that all my MT4 mill tools sit in the same position except for 2. The drill chuck mentioned sits about 3mm below the slot. One tool sits about 6mm above the slot and all the rest sit about 3mm above the slot. This of course may have no bearing on the thread position which would determine whether a washer is required or not. :rolleyes:

Dean

[Oldneweng]

Oops, sorry.... somehow the link disappeared.....
I bought mine on eBay as mentioned, but I can't find a link to one there either today....
At least here is a picture.
Semi-Automatic Extractor Tool for Morse Taper MK4-MK6: Amazon.co.uk: DIY & Tools (http://www.amazon.co.uk/Semi-Automatic-Extractor-Morse-Taper-MK4-MK6/dp/B005NGEZVQ)
This might even explain better how it works:
http://www.acy.com.sg/index.php?main_page=product_info&cPath=259_609_673&products_id=5581

I am also considering one of these, but I have only been able to find 1 from the US that cost over $200 at the moment.

I have had another look at my picture and it seems to me that the top jaw should be pulled back as it is tapered the oposite way to the bottom one. The one that I have found is only for MT1-3. Not big enough anyway.


I am with Bob on this one. If your tools are short put.a bolt. On the end or drop a nut on top and.use a drift. I have a mt removal tool from sweden a little better design then the ones pictured.

Andre, in what way is your tool a better design? It is hard to see how it works from the picture.

Dean

[mahgnia]

The other option is a special drawbar with differential threads to remove the tool without hitting anything. A self-ejecting drawbar.
It requires the far end of the spindle to be internally threaded with a finer thread than the drawbar-tool thread and a matching thread (obviously larger than the rest of the drawbar), as well as a fixed hex end to be fitted to the drawbar. By loosening the drawbar, the thread DIFFERENCE pushes the tool out of the taper. Tightening the drawbar tightens the tool as usual - by the reverse difference of the threads.

Joe,
I've made something using the same principle for my X2 mill.
http://metalworkforums.com/f65/t198398-x2-mill-mods-upgrade#post1898875

The thread difference is that one is left-hand and the drawbar is right-hand.

Andrew

[Oldneweng]

After I had sorted my lathe I decided to finish this off.

360484

I finished it to this stage weeks ago. :rolleyes: First I thought it looked like pointy nosed pliers, but then I decided it was Big Bird.

I decided to buy an MT4 taper drift as I only have a little cheap one that came with the Chinese Drill Press and only suits MT2. This is the one that arrived. It is a Groz, if that means anything. The edge radius is way too large and I have no intention of using it in the mill untill I have made some adjustments. Probably like I did my tool.

360485

It works. I need to get a cap bolt the right length as I need a bit longer thread. I have only tried it on the ER 40 collet chuck so far. I tried to do the drawbar up real tight so I could give it a good test and the welded on nut at the top of the drawbar broke off. The bar had a centre hole in it which weakened the end of the shaft. I will turn the end down further and weld it again. The extractor tool did its job on the collet chuck this time as well and it did get pretty tight.

Dean

[KBs PensNmore]

Nice bit of work Dean, would it help if the top of the drawbar was threaded, and then the nut welded on??
Kryn

[Oldneweng]

Nice bit of work Dean, would it help if the top of the drawbar was threaded, and then the nut welded on??
Kryn

I think that would work pretty well Kryn. Thanks for the suggestion. The drawbar is 16mm, but has a 12mm nut to match the nut on the original M14 drawbar, and to fit inside the spindle spline.

Dean

[KBs PensNmore]

Dean, if the 16mm was turned down and then threaded to suit the 12mm nut, that would make life a lot easier. Didn't you say you needed some thread cutting practice :D
Kryn

[Oldneweng]

Dean, if the 16mm was turned down and then threaded to suit the 12mm nut, that would make life a lot easier. Didn't you say you needed some thread cutting practice :D
Kryn


I don't recall saying that, or did I. I suppose I do. Darn it.

Dean

ps. I have reset Firefox to try and fix page loading issues and the page format has changed. I am now seeing the "Quick Reply" window and "Go Advanced" button.

[BaronJ]

A project I have been thinking about and designing. :C

Questions for the brains trust. :-

What would be the best shape for the wedge?
How to machine radii on the arm outer surfaces to fit the extraction slot.

Any other suggestions/issues you can think of. :doh:

I am thinking of hardening and tempering the arms. They will be made from mild steel at the moment. Maybe I can find something better later. I will heat them in contact with carbon, enclosed (pipe with end caps). Reheat to red hot and quench then temper. I have seen this method on the net and I would like to try it.

Here is a pic of the closed position.

359507


Dean

Hi Dean,
Not been around for a few days, so only just seen this.

Since you are only looking for a couple of millimeters of expansion to pop out a Morse taper. An M6 bolt pushing a short wedge ought to provide more than enough force.

Putting a radius on the edges of the two legs can be done on a mill with a cheap carbide router cutter, the sort that looks shaped like a bell.

Edit: Doh. I should have read the whole thread first :) Looks nice anyway.

[Oldneweng]

Dean, if the 16mm was turned down and then threaded to suit the 12mm nut, that would make life a lot easier. Didn't you say you needed some thread cutting practice :D
Kryn

I fixed the drawbar today (well yesterday now). I shortened it slightly to remove the centre hole then machined to 12mm diam to fit the washer (about 3mm thick) and nut. I then threaded the end in the lathe, but I did not turn the thread, I used a die held square with the tailstock. Take too long to thread with the lathe, only about 10mm of thread. When I went to try it I found I had made a slight mistake. The nut should have been M10. 16mm across flats. I will make use of my unused hex collet chuck to reduce the nut to fit a 16mm spanner. The M12 nut fits inside the spline, but I have 2 other drawbars with the smaller head. I want them all the same. Using the M16 nut like this is probably better anyway as it means the shaft is bigger and stronger.

Dean