Thread: Question about way to modify the rear of a small chuck to suit a Toyo ML-1 Spindle

Hi Nev, I'm in the process of doing something similar, except that I'm using a 3" 3 jaw chuck. I can't see that it would be a problem to do it the way you suggested. I could be wrong, my partner always says I am.

Kryn

What is on the back of the chucks you intend to use?

Originally Posted by pipeclay

What is on the back of the chucks you intend to use?

Will probably use either a Unimat or Sherline chuck with the thread in the back if I can get one to suit the PCD of the chuck mounting holes that will need to be drilled. Just need to bore out to 22mm register for the Toyo.

This is what the Toyo spindle looks like.

https://www.woodworkforums.com/attach...1&d=1342854288

If possible would it be easier to make one adaptor to suit the spindle of the lathe and have the same mounting for your other attachments on the end , rather than trying to modify them to suit the spindle.

Originally Posted by SurfinNev

I have thought about how one would go about modifying the back of a small chuck so it would mount to a Toyo ML-1 lathe spindle. Three counterbored holes would also be required but that wouldn't be very difficult. I have this idea about using a piece of round bar in a lathe, machine to get it running true, then mount the chuck to it with the chuck jaws then bore the back to suit the spindle. Would this work? Would it be safe to bore with the chuck mounted to the round bar or am I crazy? Next question would be to ask if someone could do this as I have not been able to get another lathe yet. Details about the chuck, spindle and counterbored holes will be provided when and if this can be done. I may even go as far as having a three jaw, 4 jaw and possibly two of each done as I also have a small rotary table with dividing plates which has the same mount as the Toyo.

First, let me say that I am not 100% sure the Toyo ML-1 spindle nose is the same as the Toyo ML-210. But the two look very very much the same to me. So do the chucks.

If I understand you well, you have an ML-1 lathe as well as the rotary table that goes with it. But you do not have the original direct mount chucks. Amd you are considering to adapt some non-toyo cucks to suit.

I just took a few pictures from my own ML-210 chucks, so you can get a good idea how these look like and how these mount. I also took pics of my modified ML-210 rotary indexer so you see its spindle nose for comparison. There is also a parallel shaft spindle nose that I made 32 years ago from a large high tensile bolt to suit these chucks (made on the ML-210, took several hours just to rough out, but just to show you that what you want to do can be done on such a small watchmaker size lathe, if you have the will to do it). The mounting screws on the pics are M4.

The EMCO unimat chucks are almost identical in size, but have a totally different mount. I would suggest you look at these, there is a small chance it may be possible to modify them as direct mount for your ML-1. Or else, you could at least make a backplate to convert them.







Before you ask, I sold that lathe loong ago, but kept the chucks as these are very useful on my larger lathe with a rotating tailstock that I made, and on the mill too with the 24T indexer for smallish jobs. Good luck with your project.

PS: the TOYO ML-1 was a very well made little lathe from the Japanese Toyo Special Camera Co. There are not many small hobbylathes today that I could say of that they are well made.

Originally Posted by pipeclay

If possible would it be easier to make one adaptor to suit the spindle of the lathe and have the same mounting for your other attachments on the end , rather than trying to modify them to suit the spindle.

Just don't like the idea of having a different mounting style on the Toyo. I think it would look a bit odd with and adapter on the spindle and also would make other chucks stick out further.

Thanks cba.

The Toyo did come with a 3 jaw but it was damaged and couldn't be used. Would love to know some dimensions of both the 3 and 4 jaw chucks you have if you could manage to measure them. The PCD of mounting holes, the register diameter and depth.

The Toyo is in my opinion, better built that the Unimats. Also has a spindle bore of 12mm as opposed to I think 10mm for the Unimat. Just seems a lot more solid overall than the Unimats. I was lucky enough to find a thread cutting attachment with a set of nine metric gears on eBay for it quite a while ago. All brand new and genuine Toyo.

Originally Posted by SurfinNev

Thanks cba.

The Toyo did come with a 3 jaw but it was damaged and couldn't be used. Would love to know some dimensions of both the 3 and 4 jaw chucks you have if you could manage to measure them. The PCD of mounting holes, the register diameter and depth.

The Toyo is in my opinion, better built that the Unimats. Also has a spindle bore of 12mm as opposed to I think 10mm for the Unimat. Just seems a lot more solid overall than the Unimats. I was lucky enough to find a thread cutting attachment with a set of nine metric gears on eBay for it quite a while ago. All brand new and genuine Toyo.

I have never seen a Toyo ML-1 in real life. I bought a Toyo ML-210 as my first lathe, and kept it for only a few years. The reason I bought it over the Unimat was, that I felt it was better made. Price was very much the same. The Toyo lathes are still manufactured, with only slight modifications, and sold under the name Proxxon. I cannot tell if Proxxon lathes are still made in Japan. I have never seen one of these in flesh and bllood. But if you google for Proxxon PD230 you will find plenty of pics. They are expensive for a lathe of 7kg that you can carrry on your palm like a dinner platter, about US$1200. The PD230 spindle nose look very much like the ML-1 and ML-210 spindle nose. This is a picture of the PD230:

If it really is the same dimension, you could simply buy new chucks from Proxxon (will not be cheap though.....). Sadly I cannot confirm that, maybe another member knows for sure if these Toyo and Proxxon spindle noses are all compatible, or if there are subtle differences. After all, the Toyo ML-1 was made from the 50's, the Toyo ML-210 from the 80's, and the Proxxon PD230 in 2000.

I am happy to take some measurement of the parts that I have if that helps you. However, I strongly feel you need to make your chucks fit YOUR spindle nose. The registration cylinder is exactly that, a cylinder - and not a short taper as it may look like on pictures. As good as I can measure this registration cylinder, it is 22.00mm diameter and 8mm deep. The 4-bolt-hole circle is 35mm diameter, the 3-bolt-hole diameter is 28mm. Drilled oversize for M4 screws, so these diameters are not that critical and have no effect on chuck runout. For runout only the 22.00mm registration cylinder and the spindle face matter. If the registration cylinder on your rotary table is the same as mine, it is hardened and finely precision ground just like the lathe spindle, and you could use this as a reference spindle nose when modifying other chucks or making a backplate.

Originally Posted by cba_melbourne

As good as I can measure this registration cylinder, it is 22.00mm diameter and 8mm deep. The 4-bolt-hole circle is 35mm diameter, the 3-bolt-hole diameter is 28mm. Drilled oversize for M4 screws, so these diameters are not that critical and have no effect on chuck runout. For runout only the 22.00mm registration cylinder and the spindle face matter. If the registration cylinder on your rotary table is the same as mine, it is hardened and finely precision ground just like the lathe spindle, and you could use this as a reference spindle nose when modifying other chucks or making a backplate.

Perfect. The Toyo has the same three and four jaw PCD, same M4 bolts and the spindle nose is 7mm high so the 8mm depth of the chucks just allows a little clearance by the looks of it. Looks like I will be on the hunt for a couple of Proxxon chucks.

I did notice that the ML210 has a spindle bore of 10.5mm and a MT1. This is where the Toyo is better, although with the 1.5 morse taper in the spindle it will require any morse taper attachment for this to be custom made as they are non existant.

Thanks for taking time to measure things for me.

Originally Posted by SurfinNev

Perfect. The Toyo has the same three and four jaw PCD, same M4 bolts and the spindle nose is 7mm high so the 8mm depth of the chucks just allows a little clearance by the looks of it. Looks like I will be on the hunt for a couple of Proxxon chucks.

I did notice that the ML210 has a spindle bore of 10.5mm and a MT1. This is where the Toyo is better, although with the 1.5 morse taper in the spindle it will require any morse taper attachment for this to be custom made as they are non existant.

Thanks for taking time to measure things for me.

Pleasure. The MT1 of the ML210 is not standard too, it was only about half as long as a standard MT1 shaft. Both in the spindle and in the tailstock. The 210 in the model name meant 210mm between centers, and the whole lathe was only 490mm long end-to end. Just no room for full size length MT1 shafts. These are watchmaker size lathes. I still have the two drill chucks from the 210 and its milling attachment too. Very nicely made and accurate Japanese Yukiwa 6.5mm. I made one into a sensitive drilling device for the larger lathes I have.

While looking for something else I came across these chucks made by Kalamazoo. It's the 2.5" model 0023 in this link.

http://www.kalamazoochuck.com/catalo...ual-Chucks.htm

Now, am I reading this drawing properly and this chuck has a register of 22mm, with a depth of 6mm. 3 M4 mounting holes at a PCD of 28mm and also an M14 x1 thread as well?

Originally Posted by SurfinNev

While looking for something else I came across these chucks made by Kalamazoo. It's the 2.5" model 0023 in this link.

http://www.kalamazoochuck.com/catalo...ual-Chucks.htm

Now, am I reading this drawing properly and this chuck has a register of 22mm, with a depth of 6mm. 3 M4 mounting holes at a PCD of 28mm and also an M14 x1 thread as well?

The Toyo is a Japan made metric lathe with a proprietary spindle nose. Toyo is no more in business, but the German Proxxon did take over the Toyo designs. You can buy a Proxon chuck off the shelf to fit your lathe.

You are looking at American Kalamazoo chucks. The dimension drawing is imperial and at best confusing. It looks like these chucks are for a threaded spindle nose, or they make several models. But they do not say for which make exactly. And the Toyo spindle nose is definitely NOT threaded.

I would be careful. Better pay a little more for a genuine Proxxon chuck and be sure it fits. There are not many old Toyo lathes around. Especially not in Australia. They were for most people simply too expensive at their time. They did cost more than the equivalent Austrian made EMCO. And that is why you will have a very hard time trying to find 3d party accessories for it: there are none, because the market for it is far too small. Believe me. Either get a Proxxon direct mount chuck, or make your own backplate, or spend possibly a Year or two or three checking on eBay if a used Toyo chuck pops up (in all likeliness it will not!).

I am not saying that a Kalamazoo chuck could not be modified to become a direct mount to a Toyo spindle nose. But you would need another lathe to do it, preferably a larger one. And for it to come out halfway accutrate is a much harder undertaking than to simply make a backplate. You probably would have no other choice than to remove the spindle from your Toyo to use as a runout template whilst machining the back of the chuck.