mt3 problem

[TKO]

I recently bought some tools from ctc,the boring bar arbor fits the head stock ok but is too small for the tail stock,all my other mt3 tools have no problem with the tail stock,when the back of the boring head is tight up to the tail stock the arbor is to loose by quite a lot, I contacted ctc tools they said that was the way they made them and was no help at all,I wonderr if any body has an idea what I can do as I want to use the tool from the tail stock end most of the time, one would think that a mt3 male end should fit any mt3 female end,
would appreciate any help,or suggestions.

TKO

[Ueee]

All my CTC mt3 stuff works fine in both ends (oh thats wrong:D) of my little lathe. Actually i have to put a bolt on the thread at the end of my collet chucks so i can eject them. As i use them in the head too i need to take the bolt out to put a drawbar in.
Can you take a pic of the problem one up against a good one?

Edit.....the sun just came up....short of what J&H suggests, the only thing you can do is cut the front off the TS quill....not really an option IMHO!
Otherwise buy one from a different source, or make one up yourself.

[Jekyll and Hyde]

Assuming that the arbor is threaded onto the boring head, you could perhaps just turn up a threaded extension to go between arbor and boring head, same diameter as the major diameter of the MT3?

[aametalmaster]

I have the same problem with some of mine. I just place my tailstock wrench between the arbor mounted (whatever it is) and crank the wheel back and it pops right out...Bob

[pipeclay]

Does your other M/T 3 tooling fit the Headstock without a problem.

Are the lengths of your other M/T 3 tooling the same length as this Boring Head taper.

Have you measured the large diameter of your other M/T 3 tapers and compared this to your Boring Head taper.

Place some of your other M/T 3 tapers in the Headstock and mark with pencil where they stop then do the same with the Boring Head and compare.

[.RC.]

Cut some off the small end of that arbour, that makes the arbour a larger diameter then...

Of course cut too much off and then you will never eject it..

What sort of lathe is it.... Some have a tang slot milled into the tailstock quill..

[TKO]

Thank you ,Ueee,Jekyll and Hyde, aametlemaster,{i[e Clay,and .RC, I had thought about shortening the quill ,but thought that if it didn't do the job I couldn't put it back againI have taken some photo's ,but beats me how to get them into the forum now,,so I
will try and explain ,

The boring bar has a separate arbor which screw's into the back of the head piece,the largest point of the MT3 is to small ,to fit properly in the tail stock, or in other words it is a very loose fit,when up tight to the head piece to the tail stock quill,

All the other MT3 tools are much larger and there is no problem with any of them ,

My lathe as I mentioned is a Herless 11 b u k, Bought in 1989 new, has a Mt5 spindle to the head stock , the sleeve to bring it down to Mt3 ,will just allow the boring bar to fit and only just I might add, the photo's I took would give you all a clear picture but I can not see now, how to up load them to my library let alone put them in to this reply,

There is aprox 3/16th of an inch at the quill end that is clear of the measuring area,and I suppose if I took an exact measure of the boring bar MT3 large end, to see if that would work out,and the largest point in the quill 3/16th inch in,,I went out and measured it there is only 14 thou to play with and I am sure you all will say not enough to take a chance an cut the quill.

So I am wondering what's the best thing to do ,the arbor thread is 1/1/2 inch x18tpi, would cutting there MT3 part off and
boring and tapping a new bar on then cutting a new MT3 to suit what I have be the away to go,open to suggestions ,I have just gone back to car restoring and would love to sort this problem so that I can use it thank you all.
.RC most of the MT3s have a tang and those that dont I use a distance piece to eject them .

[.RC.]

{i[e Clay,and .RC, I had thought about shortening the quill ,but thought that if it didn't do the job I couldn't put it back again.

I suggest cutting the end off your arbour, not the tailstock quill...

The problem from where I see it is simply the morse taper arbour you bought is just too long.. It is hitting up inside the tailstock quill...

I am betting your lathe tailstock quill deep inside has an actual slot cut in it so it really looks like a female version of a proper morse taper shank. it is to stop the risk of any tool put in there from coming loose and spinning damaging the bore..

Your boring head shank, has no tang and I bet the tapered portion is longer then a standard more taper drill arbour... As such when you put it in, it is hitting up against that tang slot in the quill before it fits properly...

Here is a photo of a morse taper boring head arbour I made years ago... What you will need to do as shown in the photo's is shorten the end of the arbour a small amount... If you put that in as is, you will never be able to eject it (unless you also have an ejection slot in the quill you put a wedge in to knock it out)... A short bit of threaded rod cut as shown i the photo will act as a tang on a normal morse taper arbour.


http://img.photobucket.com/albums/v606/OzRinger/20130401_17372020Custom.jpg


http://img.photobucket.com/albums/v606/OzRinger/20130401_17374120Custom.jpg

[TKO]

I have managed to upload a couple of pics260957boring bar arbor removed


260958comparison of other bars can't get the pics I wont to show need more practice, because the memory is very short sorry,what I mean is I should write the method down but by the time I have reached for the writing gear memory has gone
so tha'ts my story .I will try again for the other pics.

[Ueee]

What you are saying RC is what i thought to start with, but i think the shoulder i have marked in your pic is hitting the front of the quill.

TKO, I would make a new one. If you turn the taper first you can put it in the headstock and then do the rest of the work, that way it will be as concentric as possible.
There is a thread in the Forum helpdesk section on posting pics.

Edit, Why not just try and machine a bit off the back of the arbor, the bit that is hitting the quill?

[.RC.]

Oh OK, it is hitting the other end....

That is easily fixed.... Take some off the other end... Probably need a carbide tool as it will be hardened a tiny bit...

[TKO]

The arbor MT3 is shorter than any other Mt3 that I have got ,it does not reach the full length of the quill it goes all the way into the quill and the quill is tight up to the back of the boring head and the arbor slops about it is not the same size at its larger end I have measured both the inside of the quill and the outside of the boring bar arbor and the boring bar is small ,I hope I am not confusing any body with the problem ,but the boring bar is to small for the tail stock quill, if you cut the threaded portion off it would still not fit as it would go to far in to the quill, I appreciate the comments given ,I just wish I could get the photos in that way you will see the problem.

As I mentioned before, using it in the reducing sleeve in the head stock it is only just doing the job nothing to spare.
Still trying for pics.

[TKO]

Well one more for the road ,the buckets has not got the pics as well ,but this i the problem,



http://i1232.photobucket.com/albums/ff365/aussieddie/010.jpg

[Ueee]

What RC and i were saying is machine it off like in the pic. You don't have to follow the taper, just cut it straight from the relief groove. You will probably need carbide to do it.

[nearnexus]

Is the morse taper in the quill set back from the quill face a bit?

Sounds a bit that way to me.

Rob

[Steamwhisperer]

You could buy an arbor that does fit. You might have a rogue arbor.

Phil

[TKO]

Thanks Ueee,

I think you may be right Rob as the other MT3 tools do sit well in the quill, but it is hard to know the best way to go as I would
rather make a new arbor than a new quill. I will check the quill tomorrow ,I have a loos MT3 and will try and get an accurate measument
on the proper dept of the quill , Ueee's I dear looks alright but I would hate to butcher the tool as it would take a lot of the thread away and might scoch it all up,so I will be at it tomorrow, thank you both.

Nearly missed you then Phil well the CTC mob don't think it is a rogue ,and they don't make the separate type either,they said that's what they make.
so I would have to go else where,would make it expensive ,,for the old fellow.

[RayG]

Hi TKO,

Sounds like the CTC boring bar is just not compatible with your quill. Rather than modify either, what about getting an MT3 extension sleeve?

Here's the first one I found on ebay... you might do better with a more thorough search.
MORSE TAPER EXTENSION SLEEVE 3MT - 3MT FOR LATHE ETC FROM CHRONOS | eBay (http://www.ebay.com.au/itm/MORSE-TAPER-EXTENSION-SLEEVE-3MT-3MT-FOR-LATHE-ETC-FROM-CHRONOS-/300804420037?pt=LH_DefaultDomain_3&hash=item46095731c5&_uhb=1#ht_1981wt_1165)


Regards
Ray

PS I Just noticed you are in Shepp... that's where I am. :)

[Stustoys]

But Ray, one end of the extension sleeve might not fit.:p

TKO
Whats the largest dia of the taper at "to small" in your picture
http://www.woodworkforums.com/f65/mt3-problem-168594/#post1629860

It should be bigger than 0.938"
If its not thats the problem. and a fix like Ewan/RC might be the go?
It it is bigger your quill is the problem. and maybe turning the end off it would be the go?
At least, thats the way I am reading the one taper dim chart I have checked.
Machine Tool Shanks (Tapers) (http://www.tools-n-gizmos.com/specs/Tapers.html#MT)

Stuart

[cba_melbourne]

Boring heads are made first and foremost to fit a mill. And low cost boring heads are probably aimed at hobbymills, that usually are limited by distance between table and quill. Hence it makes sense to keep the MT arbor as short as possible.

Facing off the tailstock barrel is IMO a bad idea; I would not want to modify a good machine tool, just to make it accept one particular make of tool. Especially not if it was a low cost tool. If that boring head arbor is halfway soft, I would try to face its shoulder off. If its hard, I would make a new arbor. That is fairly easy even if you do not own a taper attachment, as MT3 blanks can be bought cheaply. Another idea: the arbor of that boring head is threaded, so you can be swapped for a parallel shank arbor or an R8 or an int-type arbor. It may be possible to buy another arbor for it? I have a similar cheap India made boring head that came new in a box with 3 different arbors. You could even consider getting an MT2 arbor for it, and use a sleeve to make it MT3. Chris

[nearnexus]

Thanks Ueee,

I think you may be right Rob as the other MT3 tools do sit well in the quill, but it is hard to know the best way to go as I would
rather make a new arbor than a new quill. I will check the quill tomorrow ,.

I wouldn't face off the quill, but it would explain why the morse is loose and comes right up against the back of the fitting.

Machining off the rear of the fitting should fix it, although you may then have to take a bit off the threaded section if it bottoms out at that end as a result of being inserted further.

Rob

[Stustoys]

I should add if the taper on the boring bar is less than 0.938"* you maybe able to have another go at getting CTC to exchange it.


Facing off the tailstock barrel is IMO a bad idea; I would not want to modify a good machine tool,But one could argue if the hole in the end of the quill is larger than .938"*.......then it isnt a good machine tool regardless of the brand name on it :D....... Maybe someone reground the taper and didnt face the end? (I dont recall what lathe TKO has.) Then again I'm not to sure about the idea of using a boring head in a tailstock**, but assume TKO knows what needs to be done. If the error is in the quill this problem may reappear with any new MT3.

Having said all that, personally might be tempted to mod the boring head, but I would like to know where the error lay. Next time the mismatch may not be as obvious.


One other idea, some people like the idea of having a piece of paper around the taper. That might be enough to give you a short term fix if nothing else.

Stuart

*Unless someone else can find another size for an MT3?
**unless its for turning tapers.

[TKO]

The problem solved Rob was right after checking the quill was over size at the entrance,as there was 3/16 of an inch to the measure area ,after my calculations I decided to remove 1/16thfrom the quill cleaned end up every thing now fits proper ,made a small end peice to fit ,and I am a happy chappy,,now I know that is against the grain for most of you ,to remove the qill end but it has been that way for a long time no doubt ,I would like to thank you all including RayG ,stuart, CBA,for their comments, as well I have managed to get a photo of the finished job with the extension piece.

http://i1232.photobucket.com/albums/ff365/aussieddie/Tools/002-Copy.jpg


http://i1232.photobucket.com/albums/ff365/aussieddie/Tools/001.jpg

http://i1232.photobucket.com/albums/ff365/aussieddie/Tools/003.jpg

Also I was not right in thinking that removing the back part of the boring head would weaken the thread don't know where my head was at the time.

[nearnexus]

Looks good to me.

I think you did the right thing with the quill, as it was only a small amount taken off.

Cheers

Rob

[TKO]

Thanh's Rob ,I don't feel so guilty now,managed to find a pic of the 11 buk lathe I have

Eddie
261185

[nearnexus]

It's not actually going to make any difference to the quill travel, as the effective morse taper is still in the same position.

Lathe looks good.

Got that Taiwanese style about it :)

Cheers

Rob

[Ueee]

Good to see you have it sorted:2tsup:

I checked my TS taper this morning, and the big end measures .930", 8 thou under the gauge line size. I guess it just depends on the lathe and whether or not the taper has been re-ground at some stage.

[TKO]

You are right Rob it was really surplus any way.it is a Taiwanese lathe ,had it for 20 odd years and still in very good condition,does not get to much work now,I did make a alteration a long time back, to change the belt over you had to lift the cover and it was a nuisance
there was always tools to shift ,so I altered it and removed the part's that lifted the lid and fixed a handle out side that you can see behind the chuck that would activate the same as what the lid would do, would have been the best thing I have done to the lathe,had to fix two rollers to the back of the head stock to take up the slack so that I could change tools without having to turn of the motor or lift the lid.


Hi there Ueee,the lathe tail stock has never been ground,the chuck has been trued up once some years back, other than that it is still in very good condition,I had the boring bar as a present ,mostly I used the cross slide for that type of work,and i was disappointed when it would not fit the tail stock many thanks for your input,.

Eddie