Chinese MT reamers .

[stragenmitsuko]

I seem to have damaged MT3 of my tailstock .
There's a circular burr , halfway down the bore .
Most likely I have a drill with a damaged shank somewhere , and that transferred
to the tailstock .

I know there are special reamers to repair these , wich 'll cost you a fortune .
So I was wondering did any of you ever use chinesium ?

They're cheap , and most certainly won't last a lifetime but as it's
only for a one time cleanup maybe it's worth considering .
It's a set of two . One coarse and one finisher .

Pat

 

[coulsea]

I have the same problem, must have got a bit of rubbish in there and it spun while drilling a 25mm hole. I have these reamers on my ebay watch list, just have not bought them yet $37 Aus they should do the job as you only have to take the bur out.

 

[stragenmitsuko]

I ordered a set , will let you know how it turns out .

 

[GrahamJTaylor49]

Have made my own reamers from time to time, That is one job that really can be fun.
Chambering reamer for 0.30 Wolf for long range pistol shooting. .460 Weatherby necked down to .30 cal.
Takes 120 grains of Reloader 22. Boy do you get a fireball out of the gun. Set fire to Century and Stickledown ranges.
When making the reamer I turned the outside down to the profile in silver steel. Polished the blank then milled the
slots for the swarf. Oil hardened, bright cherry red. Very carefully ground the back relief on my tool and cutter grinder and finished it off with a diamond wheel. The result was more than acceptable and the finish inside the breach worked. I used the gun on Stickledown range at Bisley and although shooting at 1000 yards still got a 10" group. Now, thanks to our wonderful government we no longer have our hand guns and have to turn our hands to other pastimes. Stay safe
everyone and have a very happy Christmas.

 

[clockworkcheval]

With a similar problem in the MT2 of my tailstock I was lucky to find a colleague who had a MT2 reamer. I got it on loan. He advised me to be extremely careful in applying pressure as these reamers have a tendency to 'dig in' and destroy the bore. He even advised me to make a small backstop for the reamer that only allows a tiny amount of play. After cleaning up the bore I checked with a blued clean MT2 shank and I found that I had to do this several times before the result was satisfactory.
As a precaution for future damage I have ground back the middle part of all my MT2 shanks. When they bear only on the larger and smaller diameter but not in the middle they seem to hold better.

 

[Chiptosser]

I do the same thing, Clearing the shank.
I usually advise not using a reamer on a tail stock receiver, most people will over do it, then you have more of a mess than you started with.
One way of checking for the scared spot is:
First step: Clean the inside of the receiver (tail stock quill} take it out of the tail stock so you can see inside. Check for flakes of metal. Scrape around the bore with a metal scale or anything that you can feel the surface for irregularities. Go around the surface with a fine grit stone to find high spots.

This is the same procedure you would use on a tapered nose spindle. when you have specks of metal imbedded on a surface, the metal around it is displaced. You will see this when you stone the surface. Those high spots need to be taken down the the surface height or below.

use a true clean shank, cover it with permanent marker, slide it into the receiver and lightly wiggle, twist, push in. This will show you where the gouge, flak of metal is, and where you need to work. The reamer will take some of the high spot off, but it will also deflect the reamer opposite of the displaced material causing more damage.
It is easier to work on the suspect area than losing your accuracy.

 

[ChazzC]

I have MT & R8 cleaners – the MT's came from McMaster at a somewhat reasonable price; I 3D-Printed the R8 one: R8 Spindle Taper Cleaner by NeverDun. Thingiverse also has MT ones, but I prefer the ones that have felt wipers. Replacement felt may be found here: Duro-Felt Products – reasonable prices, especially if you can find what you want as a close-out. I also made at "top-end" R8 cleaner from Sc 40 1/2" ABS Pipe (my eBay set of Metric R8 Collets were a hair over spec at the back end so I honed the top of the spindle bore and wanted to make sure I got all of the grit out:

I also have MT reamer sets, and would use them as Clock described if absolutely necessary. I also like Chip's idea, but will try it first (I have an MT-3 sleeve that I recently discovered did not have a concentric bore, but the outside is fine so it would be a good candidate).

Many, many (50 +/-) years ago, I was taught to lightly rub soapstone on the surface of long tapers to make them easier to dislodge in the distant future and also add a bit of friction. This has always worked on Jacobs & Morse tapers, and I the times that I have checked did not affect the concentricity of the arbor. And yes, real soapstone "pens" are still available from welding suppliers (don't use the substitute materials they also sell):

 

[stragenmitsuko]

I guess this must be a world speed record .
I ordered the a set of reamers a week ago , and they arrived today .
That's 8 days , weekend included , from china to here .

At first sight they seem OK .
Carbon steel not hss , as advertised .
Could do with some stoning I'de say , especially the finisher .
Anyway ; 24$ , can't expect the world for that kind of money can you .



Here's a picture of my tailstock .
I genty tried the reamer , with a backstop to avoid it digging in . That was a great suggestion btw .
The reamer does remove the high spots quite easily , but stops cutting once if fully engages the bore .
Judging by the sound and feel of it , it would seem that my quill is harder or at least as hard as the reamer .
Wich in this case is a good thing .

Finished it with some 600grit , and while I was at it I cleaned up the drill chucks and live centres and all other tooling as well .

What a difference , everything is rock solid again as it should .

 

[ChazzC]

I have had some shipments from China arrive before USPS Priority Mail from the West Coast: it depends on whether mainland or Hong Kong and also how close they are to shipping hub.

 

[Apprentice707]

About 6 years ago I was on holiday in Florida when I saw on a well-known internet auction site a 6 jaw, 5-inch self-centring chuck for sale in China at a very reasonable price so I decided to buy one. I asked for it to be delivered to my home in the UK. This appeared to be no problem so I bought one.
The order was placed around midday (Florida time) so 17:00 hrs in the UK on a Monday. On the next day (Tuesday) I caught a flight overnight to the UK and arrived at my UK home at around 11:00 hrs on the Wednesday. At 14:00 hrs there was a knock on the front door and there stood a guy with a small cardboard box which was addressed to me. Low and behold inside was my 6 jaw chuck.
By my calculation, this took less than 48 hrs to process, ship and deliver, very good considering that the Royal Mail takes longer to deliver a parcel From Birmingham to Ipswich. Even now I wonder if this really happened but I do use the chuck so I guess it did!

 

[stragenmitsuko]

That is an amazing story .

 

[Apprentice707]

I still pinch myself Stragenmitsuko.

 

[William May]

Sometimes things DO work out! I order castings from GLR Kennions and from Reeves. Usually they take 4-6 weeks to arrive in the southwest U.S.
But I got one package from Kennions in just 5 days! Wonders will never cease! It had to be a happy confluence of the package being in the right place at the right time at EVERY SINGLE STOP, all the way from England to Arizona!