New Granville 7x18 lathe back from the dead.

Wow that's interesting. Never thought of going electronic but I think as a learning curve I am going to stick with the gears. It looks like I have the set like yours but the two idler gears under the main drive - I have two different sizes - it seems to work ok and can drive forward and reverse from them. It's from there down - the problem is - the cluster gear only has one gear so I will need to work out how to attach a second to it - the any other combination gears - I have small gears with a very small pin in them that could locate in small holes in larger gears pushed into a movable spindle and locked with a grub screwed ring - will try that. The biggest issue is a lead screw with no keyway.
 
There should be two identical idler gears on the fwd/rev lever to give you fwd/rev feed. Looks like you are missing one.

How are you intending to do the keyway?
Does the end of the leadscrew fit the gears? It seems large, do you need to turn it down to fit the gears? If it's already the right diameter you could improvise with a short keyway just where the gear needs to be to lign up.

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GrayTech said:
There should be two identical idler gears on the fwd/rev lever to give you fwd/rev feed. Looks like you are missing one.

How are you intending to do the keyway?
Does the end of the leadscrew fit the gears? It seems large, do you need to turn it down to fit the gears? If it's already the right diameter you could improvise with a short keyway just where the gear needs to be to lign up.

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Click to expand...
 
Ok I have just been in the workshop and tried a few things - note this is a rough and ready test even a cable tie holding gears!!!

I found gears with small pins that fitted into larger gears so looking at chart I made up a five feed set kind of and it works except I have not yet fixed the lead screw gear.

The lead screw fits the gear - I wonder if I could pin it to a collar with some grub screws? I will look at making a short key way - but for now I am happy with progress.

The two idler gears - I have 2 but each is a different size but seem to work - I will explore that also.

Pics attached and a video of it running although the final gear doesn't turn as I am a pin short at the moment.
 

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Hi again - I got two new idlers but got 20 tooth ones but they won't work as too many teeth so it looks like I need 2 x 18 teeth

Do you know if two 18s is correct?
Cheers
 
Idlers for which position? Fwd/rev lever?


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Looks like you have it pretty much figured out from the video.
For reference you can download a myford 7x18 manual. Gears are interchangeable as are many other parts too.

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GrayTech said:
Not using gears on mine any more. I built an electronic gearbox for it.
Stack of gears I have are pictured, large bottom gear is a (127 or 123 tooth?) metric thread conversion gear.

The brass plate shows the recommended combination of gears for each of the list of possible imperial thread pitches in left column. There are two adjustable gear studs on the adjustable arm. Ask if you need further info. There are apps and calculators out there that will calculate the required gear setup for any possible thread pitch in metric or imperial given a specified set of gears you have available.

P.S. I have an extra drive belt cover for this model.
168373bd70e7e7fa58b02553b6a8891f.jpg


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Do you have more info about the electronic leadscrew? What did you build?
Because it looks interesting!
 
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