1957 Colchester Spindle Adaptor to accept MT3 ?

dansawyer

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The lathe is a 1957 Colchester 13x36 'engine' lathe. I have found 2 references to the spindle taper, one is MT3 and the other is MT5. I would like to find or make an adaptor for the spindle to accept MT3 collets.
Does anyone know what the spindle actually is? It cannot be a standard MT3, however it can be bored to an MT3 angle. There are MT5 to MT3 adaptors. If it is an MT5 then an adaptor would work. On the otherhand the MT5 and MT3 angles are slighty different and standard MT5 collet would most likely not fit properly.
Thanks in advance, Dan
 
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Dan,

First thing that you need to do is to give the model number of your lathe. Armed with that and the year of manufacture, you or someone else can look for an owner's manual on it. However, Colchester may have sold the model with more than one spindle tapers. So you would have to try to determine whether or not the full model number would determine what taper it came with. For example, the Clausing vertical mill was available with 2MT and another on that I forget at the moment. But which one it had was identified by the exact model number.

Finally, Machinery's Handbook has a table of MT dimensions with which you can ID the taper, assuming that it is actually MT.

WRT your next to last sentence, if the spindle taper is an MT5, any MT5 taper drill, collet, adapter, etc will fit. It wouldn't matter whether MT3 has a slightly different included angle or not.
 
Thank you. I have been looking for a model number and can't find one. The serial number indicates year of manufacturer as 1957, the only remaining name plate is Colchester 13x36 engine lathe. This is all I have been able to find. If there is a better place to search please let me know.
I have a 1966 Colchester 13 manual that is very close.
(BTW is wa5cab a call sign? I am kb0qil. 73 Dan)
 
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You should be able to make a spindle adaptor from a MT 5 reducing sleeve ......the original spindle bush is 5 to 3mt,but some say its not an exact #5 .....anyway ,first step is to get a #5 sleeve and check it in your spindle ......the sleeve will be too long ,but thats not important,you can cut it to length ......you willl also need a bit of (preferably) bronze/brass bar to knock out the cutoff sleeve....I had heaps of old Master bits ,and was using the bushings as spacers for hold downs on the radial drill.....but where are they now? I may still have them ,but have recently scrapped 40 tons of old stuff as the land is sold.
 
You should be able to make a spindle adaptor from a MT 5 reducing sleeve ......the original spindle bush is 5 to 3mt,but some say its not an exact #5 .....anyway ,first step is to get a #5 sleeve and check it in your spindle ......the sleeve will be too long ,but thats not important,you can cut it to length ......you willl also need a bit of (preferably) bronze/brass bar to knock out the cutoff sleeve....I had heaps of old Master bits ,and was using the bushings as spacers for hold downs on the radial drill.....but where are they now? I may still have them ,but have recently scrapped 40 tons of old stuff as the land is sold.
 
That aligns with what I had concluded. I have ordered a MT5 collet, I will let you know if the taper matches.
I will try to remove the center shaft. Those gears have small ridges I will file off in hopes it helps with the overall noise issue.
Dan
 
(BTW is wa5cab a call sign? I am kb0qil. 73 Dan)
Dan.

Yes, WA5CAB is my radio call sign, since 1962.

We only have about three Colchester 13" lathe manuals in Downloads. Whether one of them matches your machine or not, I couldn't say.

One comment that I will make about Morse Taper reducers is that there are two styles. The style that you don't want sticks out of the spindle two or three inches. The style that you want doesn't.
 
The spindle bore is 1 1/2",so there cant be a smaller taper in the spindle than #5.......compared to some lathes ,the spindle isnt very thick either ,the OD in the front bearing is 2 3/8",IIRC.
 
The MT5 to MT3 adapter arrived and I have inserted it in the spindle. The good news is that it fits and there is very little excess sticking out ot the spindle. The bad news is 'it does not feel quite right'. There is noticeable free play in the tang end just before it contacts. The MT5 is a slightly shallower taper than the MT3. If the actual spindle has an MT3 angle then the MT5 is contact the large diameter end before the smaller end. I am on my way to pick up some Prussian Blue to test where the contact actually is.
 
The usual comment is that the spindle is "nearly but not quite" a #5 Morse .
 
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