# Cast iron nut



## savarin (Mar 5, 2021)

I needed a 1/2' 13 tpi left hand thread nut for the treadmill motor that I'm intending to use in place of the original one on my lathe.
I dont have an internal threading tool small enough for a hole that size so I checked out the cost of a tap on line.
Hmmmm, I dont think so at $139 AU + shipping.
I decided to cut the threaded  part off the treadmill fly wheel as I wont be using it.
I mounted it vertically in the little vertical slide, used a degree wheel to get the 6 sides and went at it with a 16mm end mill.


A few passes back and forth and we have 6 sides.


A quick clean up in the lathe to remove the sharp corners and we have a usable nut.


I am a little concerned regarding its strength but its only used to keep the cog wheel from working its way off the shaft so I'm hoping that will be strong enough.


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## Downunder Bob (Mar 5, 2021)

Another problem solved Charles. How are you going with setting up your new workshop?


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## savarin (Mar 5, 2021)

Its slowly coming together Bob, lathe and drill press sorted, most of the shelving, two more benches to build then get the last bits across including the mirror grinding machine and furnace. I need to cast some bronze for a clutch hub on the spindle. When the cogs arrive I can start designing that then it shouldnt be too difficult to finish the job.
What I really have withdrawal symptoms from is the bino, I havnt worked on it for over a year, I'm desperate to get back to that, I wanna see the deep sky with both eyes.
Hows everything your side of the country?


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## Shotgun (Mar 5, 2021)

I broke the fan off the tread mill motor I put on my mill.  I worked in a fix, but I'm not completely happy with it.  I like your fan design, and I think I'll be copying it.  

You can see what I did at https://rumble.com/ved44z-the-wrong-fu-tread-mill.html


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## Flyinfool (Mar 5, 2021)

I know this place does not ship across the pond, but such a thing is available a lot cheaper than that tap.








						McMaster-Carr
					

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.




					www.mcmaster.com
				




Where there is a will there is a way.


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## savarin (Mar 5, 2021)

Shotgun said:


> I broke the fan off the tread mill motor I put on my mill.  I worked in a fix, but I'm not completely happy with it.  I like your fan design, and I think I'll be copying it.
> 
> You can see what I did at https://rumble.com/ved44z-the-wrong-fu-tread-mill.html


My fan was just bolted to the inside of the flywheel so were just vanes sitting in the recess with the side of the flywheel flush with the back surface of the fan. The flywheel rim that you turned down sits over the gold flange on the motor with about 1/16" clearance.
I'm looking into making a sheet metal shroud to cover the fan in the hope that will work.
I'm wondering how hot the motor will get as it wont be working as long as it would on a treadmill so maybe it wont get very hot.


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## savarin (Mar 6, 2021)

This is how the fan sat in the flywheel


When its on the motor there is just a tiny gap for the air to pass through


The blades almost touch the gold flange


I will need a shroud to enclose the blades so I'm looking for a can that is the correct size to avoid trying to make one.
This is the control panel so far, I will get a larger dia knob for the speed control, the switch is for forward and reverse and the large red knob is the emergency cut out.


In use the emergency cut out will be turned on, the switch set to forward or reverse, turn up the speed dial. To stop turn down the speed dial till it clicks off.
The speed controller is very simple240V ac in, up to 240V dc out, the motor is rated to 180V dc so I will add a stop so I cant turn it past 180V output.


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## Shotgun (Mar 6, 2021)

Which controller did you use?  I used a mc2100LTS uses a generated signal from the $10 device that gives me a digital readout of what the duty cycle is set at.

I have an MC-60 controller sitting here next to me that needs repair.  It uses a pot for speed control.  If I get around to putting that on my drill press, I'll mark the control box to show the rpm.  I've got a laser tachometer that I use measure the spindle speed.


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## 7milesup (Mar 6, 2021)

Flyinfool said:


> I know this place does not ship across the pond, but such a thing is available a lot cheaper than that tap.
> 
> 
> 
> ...



No, no.  Where there is a *MILL* there is a way.


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## 7milesup (Mar 6, 2021)

I know what you mean Savarin about tap prices.  I am making a T nut for my new QCTP and needed a 16x1.5 metric tap.  Yikes, they are expensive.  I have never done internal threading before but it looks like I am about ready to learn.


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