Thread dial indicator.

[Tozguy]

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I don't see it in my manual,some pages nissing and you can't find this lathe model on the Internet.

Suzuki, if you provide us with the exact thread spec of your lead screw, then the thread dial gear from any lathe with the same lead screw should work. Maybe we could provide you with the part number and source for a gear only and you could make the other parts to use that gear on your lathe. Unfortunately my lead screw is inchy or I would provide you with that information.

And as RJ mentioned above in all likelihood it would be rather simple to fit a whole thread dial from another metric lathe with the same lead screw.

 

[Suzuki4evr]

Suzuki, if you provide us with the exact thread spec of your lead screw, then the thread dial gear from any lathe with the same lead screw should work. Maybe we could provide you with the part number and source for a gear only and you could make the other parts to use that gear on your lathe. Unfortunately my lead screw is inchy or I would provide you with that information.

And as RJ mentioned above in all likelihood it would be rather simple to fit a whole thread dial from another metric lathe with the same lead screw.

I am trying to figure that out now. I have a thread gauge, but it only goes up to 5.5mm. This leadscrew has a very strang pitch. My caliper is set on 25.4mm (1'), as you can see,but the thread does not seem to be imperial.

The nominal size is 40mm and the minor size is 27mm. So does this mean it is a 40×13 leadscrew or do I have it totally wrong?


I found the diagram in the manual.This is the diagram out of the manual,but it does not say anywhere the leadscrew pitch or the size of the gear and other thingI do not understand is the clock section on when to engage the halfnut on wich number for wich pitch. Can you declare this maybe.

 

[Tozguy]

Another way to measure the pitch is with a metric ruler. Measure the length of 10 threads and divide by 10.
That is a strange thread tho.

 

[plunger]

Its a bulgarian lathe?Would it not be metric.2,5mm?

 

[bhigdog]

Something wrong here. I can see a half nut engaging with that shaft but I can't see a smallish thread dial gear doing it. One tooth would almost be disengaged before the next engaged...........Bob

 

[Tozguy]

So does this mean it is a 40×13 leadscrew or do I have it totally wrong?

I agree and would call it a 40x13mm thread also.
Based on the drawing of the thread dial that you provided above, the gear looks rather large and the lead screw threads are deep. Just eyeballing it, a gear with 25 teeth would mesh with the lead screw and would only be approx. 100 mm or 4'' in diameter. Hopefully sharper minds will be along to shed more light.

 

[Tozguy]

The latter part of this video shows a neat homemade metric thread dial.

 

[Suzuki4evr]

Its a bulgarian lathe?Would it not be metric.2,5mm?

It looks to big for 2.5mn,but I am going out to the shop in a while and try to figure it out again.

 

[Suzuki4evr]

Ok guys I have looked it up now. When measuring metric threads,you measure it in threads per millimeter from credt to crest,but on the ACME thread or trapezoidal thread,you woul measure and what I have concluded now,it seems that the leadscrew I have is then a 40×12mm leadscrew. I think this looks like a reasonable conclusion. But like Tozguy said,it is a large and very deep pitch. What do you guys think of my conclusion and the big question is what size OD must the gear be for this? I know now I must have a 15T and 14T gear to cover the metric spectrum.

 

[Tozguy]

To get a more accurate reading with your caliper, open the caliper out and measure as many threads as possible. Then divide that length by the number of threads in your measurement. Be aware that the result does not have to be a round number, it could be 12.5mm for example.
I am no gear expert but to get the circumference of a 15T gear to match your lead screw just measure the length of 15 threads on the screw, then divide that number by pi (3.1416). For the 14T gear measure 14 threads on the screw. That will give you a ballpark diameter for the gear.
How did you determine that a 14 and 15 tooth gear is required?