Lathe Hack and old school tool use.

[Worth1]

Originally Posted by dmforcier

There is a show on PBS called A Craftsman's Legacy, where they talk to a different type of old-school craftsman each week. Jewelry maker, ceramicist, bookmaker, etc. Today they had a clockmaker cutting and mounting his own gears. I couldn't watch closely, but most PBS shows are available online. Check it out.

This is a guy on YouTube that is making his own clock from raw material it is amazing.
https://www.youtube.com/channel/UCwo...Sx6R6-BnIjS2MA

[Worth1]

Goofed post.

[Worth1]

A few random observations.
There is a guy on YouTube that has a 9 inch South Bend lathe from 1950.
He found a 13 inch South Bend for an undisclosed price from 1941 it was sold to a school out of the factory.
School lathes get beat up big time and this one is.
Many parts are wore out the beds have a pretty good amount of wear.
Hammer marks all up and down the ways.
The apron is wore and gouged on the bottom.
The tumbler lever has been busted off and re brazed on by an idiot.
Covered in rust.
The housing the worm runs in that makes the carriage move is worn out on the main thrust side.
It only has a 1 horsepower motor for a 13 inch lathe.
Flat belt drive.
A boat anchor.
It will cost a fortune to get the ways reground and flaked.
The way will still be unhardened and that doesn't include what ever wear there is on the tail stock and apron.
Now he is looking into an account so viewers can donate money to get the late fixed.
I wouldn't give one red cent to anyone doing this.

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[Worth1]

I typed all of this out yesterday and erased it because I didn't think anybody cared or wouldn't understand.
But to devil with it I am going to do it again even if I am just talking to myself.

For some time I have been wanting to cut 11 1/2 threads per inch on the lathe.
the reason is that all of the smaller pipe treads are 11 1/2 threads per inch with a taper.
Here are some of the complacations involved.
I have to set up the gearing in a way that will come as close to it as I can.
The closest is 11.488 not 11.500 threads per inch.
That is very close.
This can be done by putting a 35 tooth drive gear and compounding the idler gear
So the 35 tooth goes to a the 91 tooth side of the idler gear and the idler gear drive the 40 tooth gear from the 86 tooth side.
Now the idler gear becomes a compound gear.
Then I put the quick change gear box to the 9 threads per inch setting.

Now here is the next problem if you do this sometimes depending on how everything works you cant use the thread dial to cut threads you have to leave it engaged.
This is a pain in the rear to do it this way.
So anyway I set it up like this yesterday and gave it a try.
Instead of assuming I cant use the tread dial I a used it anyway according to the setting it says to do for 9 threads per inch, engage on the number 1 every time.
It worked like a charm and the cutting tool tracked on every cut.
I think the reason it worked was the ratios are still even numbers or something in the gear set in the back.
Not really for sure.

Now for the crazy part.
I am threading in a different way than normal.
The way they say to do it is to thread from right to left.
This is a nightmare if you dont disengage the half nut in time and you will crash into the shoulder of your work and well crash.

Now I am putting the cutting bit on a boring bar on the back side of the work and running the spindle backwards and threading from left to right.
Now I dont have to worry about stopping in time.
My next move is I need to make a taper attachment for the machine.

Worth

[dmforcier]

Geez. Surely a pipe thread should be a common setup. There's no instructions in the book?

[Worth1]

Originally Posted by dmforcier

Geez. Surely a pipe thread should be a common setup. There's no instructions in the book?

Not all lathes cut the same threads per inch there always seems to be a set missing.
Some if which are very standard threads.
The other thing is there is no way they could put on a placard the 600 some odd threads I can cut.
An example is 27 threads per inch which what 1/16 and 1/8 thread pipe sises are heaven forbid anyone cut that small.
Nowhere on the thread chart does it say I can cut this thread.
But if I swap out the top 40 tooth gear and put in a 60 tooth gear then set the gear box up to cut 18 threads per inch it will cut 27 TPI dead on.

The pipe sises that use 11 1/2 are 1 inch through 2 inch plus hose bibs.
The rest I can cut as they are 8 threads per inch.

This brings up the reason I chose this one over another one.
It had most of the gears inside the quick change gear box mine has a quick change gear box plus a set of 7 change gears I can swap out on the outside.
I think the other one had one maybe and you had to flip flop that one all of the time to cut some of the standard threads.

[Worth1]

I mentioned I was running the lathe backwards to cut threads.
This is great until you mess up for some reason and forget to run the spindle backwards.
If you do this you will end up cramming everything the wrong way and creating one hell of a mess.
As you can see in the pictuer the tool needs to feed to the right and not left.
If you accidentally put the lever in the forward position you can see what will happen because it will go to the left.
I haven't done this yet and I dont intend to all it takes is one time.
Here is my solution to the problem.
I checked the wiring and tested to see which one was the forward wire I will put in a bypass switch.
The forward reverse spindle control is activated by way of a lever that turns a rod the rotates a cam that opens and closes switches.
I traced out the wire and will put the bypass switch on the wiring panel in the back.
Simply by removing the wire and running it through the switch and back on to the terminal.
By opening this circuit the forward rotation will no longer work but reverse will.
Here are the pictures of the setup and how it works.
My next project will be a reverse jog bottom.
I have a forward jog button but no reverse jog button.
What they do is allow you to bump the lathe just a wee bit and not turn it on all the way with the main control switch.
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Got the forward bypass switch installed.
All I have to do to run out of bypass is to flip the red cover up and flip the switch.
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[Worth1]

No more buying threaded PVC pipe change over couplings or nipples.
All pipe has a taper of .750 per foot.
By calculating how much taper there is per inch you can evenly cut in that much taper as the machine moves by moving deeper to a predetermined amount buy the time it gets to the end of the thread.
In this case it was about .024 I had to turn the dial as it cut.
I only had to do it on the last pass.
You cut the threads so the part just starts to go on and then cut the taper.
By hand of all things.
This is not as hard as it may seem.

Here are the steps.
Count how long it takes for the tool to move from one end to the other.
In my case it was the count of three.
Now I practiced turning the dial smoothly .024 in that same amount of time.
Once I had that down I cut the taper.
Any irregularity will be taken care of when you screw the fitting on.
This counting and moving is about the same way as playing music.
By running everything backwards you dont have to worry about running into anything.
You can keep your eye on the dial and counting.
Works for me.

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[Worth1]

I have been fooling around making a list of the diametrical (DP) pitch and modules (Mod) of gears.
DP is imperial and Mod is metric.
To make a list if the thread pitches on the lathe that will cut these I have to go through all 600 some odd settings and find them.
To do this I have to find the circular pitch of the DP, this is the distance from one tooth to the next.
Once I get that I can take a tread pitch TPI divide that into 1.000 and it will give me the distance from one thread to the next.
This I then match up with the circular pitch of a given DP pitch.
This is all going on a list.
An example is a metric module of 1.5 it took some doing to get it and my end gears in the lathe are a module of 1.5 the equivalent of a DP of 16 but not exact.
Plus I had to convert the MM to imperial to get another answer I needed.
So I found the gear set that would cut this module and it drove me nuts because I cant disengage the half nut cutting metric.
Then I got the bright idea of going back on my list and seeing a gear set that I can cut imperial and disengage the half nut.
Here is the 1.5 Mod setting. after I had my answers this distance between the teeth are 0.1851 this is as close as I can get I think this one is dead on with my lathe.
The 5.5 thread pitch setting on my lathe will cut a lead/pitch of .1818 distance between threads.
This is a difference of .0033 not enough to amount to a hill of beans.
Here is a pictuer of the test the cutting tool isn't exact and the thickness of the pipe wont let me go to full depth.
The top one would be a 25:1 ratio and the bottom a 60:1 ratio if it were a worm drive and worm wheel.

[Worth1]

Here is a pictuer of the stuff I am talking about plus more and an explanation of DP.
Why do I mess with it?
It keeps the mind working.
DIAMETRAL PITCH SYSTEM
All stock gears are made in accordance with the diametral
pitch system. The diametral pitch of a gear is the number of
teeth in the gear for each inch of pitch diameter. Therefore, the
diametral pitch determines the size of the gear tooth.

Gears.JPG

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I wanted to clean the filter of my Bunn My Cafe CPU coffee maker and used vinegar in a little cup
Worked great.
What didn't work great is the glue they used to glue the screen in is epoxy based,.
This means acidic acid eats it.
The screen came out.
So I had to do something I used a C-Clamp a lid a small socket and some wax paper.
The wax paper keeps the epoxy from gluing the lid to the screen.

Back in business I hope it stays it should.

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[Worth1]

The fix was an overwhelming success.

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[dmforcier]

Coffee itself pretty acidic. I wonder if it was doomed to separate even without the cleaning.

[Worth1]

Originally Posted by dmforcier

Coffee itself pretty acidic. I wonder if it was doomed to separate even without the cleaning.

The acid I used was a lot stronger than the coffee acid.

I knew it was doomed from the beginning but it didn't matter as the thing was stopped completely up.
It has ran for years without fail.
I had just neglected to take it out and clean it for some time and it got the best of me.

Helpful hint.
If for what ever reason you get epoxy or any two part risen or the spray expanding foam on you or stuff vinegar or acidic acid will take it off.
Not oil not soap and water.

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