RCD tripping with lathe

[GRW]

hum ill have a fiddle with it not sure it will will as easy as u make it sound but maybe I can picture it

Interesting stuff. Know sod-all about Lathes but I think I get the external lever/linkage idea.
- White ball exchanged for a pivot connected to vertical linkage bar with another pivot at the top.
- new horizontal bar connected to top link which then goes through a slot in the door/cover.
- door cover has 2 half-circle cups either side of the slot for a centre pivot for the protruding bar to sit in (so it's easy to remove the centre pivot & take off the slotted door/cover if you want access)
- put the white ball handle on the end of the protruding bar.

(Raising/Lowering the external handle operates linkage, which operates the lever you now operate directly).
(Make the door out of thick perspex & you can still see what's going in there maybe?)

 

[123hotchef]

Interesting stuff. Know sod-all about Lathes but I think I get the external lever/linkage idea.
- White ball exchanged for a pivot connected to vertical linkage bar with another pivot at the top.
- new horizontal bar connected to top link which then goes through a slot in the door/cover.
- door cover has 2 half-circle cups either side of the slot for a centre pivot for the protruding bar to sit in (so it's easy to remove the centre pivot & take off the slotted door/cover if you want access)
- put the white ball handle on the end of the protruding bar.

(Raising/Lowering the external handle operates linkage, which operates the lever you now operate directly).
(Make the door out of thick perspex & you can still see what's going in there maybe?)

sounds easy! will I get enough movement on the lever though? it moves through more than 180 degrees to drop-tension right now

 

[GRW]

sounds easy! will I get enough movement on the lever though? it moves through more than 180 degrees to drop-tension right now

Hmm... in theory it's all down to the leverage ratios and the length of the levers.
Without being too scientific about it (I ain't clever enough) ... if the top horizontal lever that you actually move - can have a longer section length aft of its "central" pivot point, AND is longer than the existing bottom lever arm with the ball on currently....then it should have travel/range to spare?
You could start with a longer lever, test it, and then trim it till you get the optimal...or maybe use flat bar for the top pivot... and drill multiple mount holes for the centre and end pivot clevis pins - giving you leverage options to play with and find the optimal?

 

[123hotchef]

Hmm... in theory it's all down to the leverage ratios and the length of the levers.
Without being too scientific about it (I ain't clever enough) ... if the top horizontal lever that you actually move - can have a longer section length aft of its "central" pivot point, AND is longer than the existing bottom lever arm with the ball on currently....then it should have travel/range to spare?
You could start with a longer lever, test it, and then trim it till you get the optimal...or maybe use flat bar for the top pivot... and drill multiple mount holes for the centre and end pivot clevis pins - giving you leverage options to play with and find the optimal?

it is all going to be a trial and error game I think.

 

[brightspark]

Interesting stuff. Know sod-all about Lathes but I think I get the external lever/linkage idea.
- White ball exchanged for a pivot connected to vertical linkage bar with another pivot at the top.
- new horizontal bar connected to top link which then goes through a slot in the door/cover.
- door cover has 2 half-circle cups either side of the slot for a centre pivot for the protruding bar to sit in (so it's easy to remove the centre pivot & take off the slotted door/cover if you want access)
- put the white ball handle on the end of the protruding bar.

(Raising/Lowering the external handle operates linkage, which operates the lever you now operate directly).
(Make the door out of thick perspex & you can still see what's going in there maybe?)

better explained than i did

 

[Agroshield]

... will I get enough movement on the lever though? It moves through more than 180 degrees to drop-tension right now

Just some ideas for you. Gears are levers with teeth. 90 degree rotation of a 40t gear will give 180 degree rotation of a gear with 20t. Similarly with belts and pulleys and timing belts and pulleys. Bowden cables over a curved surface can have reasonable travel and also go around corners (e.g. motorbike twistgrip). I think it was the old Maytag petrol-powered washing machines had 1/4 of a gear on the 'kickstart' driving a pinion on the crank to start them. Project Binky when they did the central locking mechanism in the doors.

 

[123hotchef]

well no tripping today I should have made the clutch years ago! it has speed up the work a fair bit by not turning the motor on and off every chuck change! Bending down to the lever is tiring though! that needs work now not much room for rods and pivots points in there but I am sure it can be done in a cunning way when I have a spare half a day!

 

[GRW]

well no tripping today I should have made the clutch years ago! it has speed up the work a fair bit by not turning the motor on and off every chuck change! Bending down to the lever is tiring though! that needs work now not much room for rods and pivots points in there but I am sure it can be done in a cunning way when I have a spare half a day!

You could just put a spring on the bottom lever that defaults to disconnect the drive, so you need a simpler extension to operate it without pivots????

 

[123hotchef]

You could just put a spring on the bottom lever that defaults to disconnect the drive, so you need a simpler extension to operate it without pivots????

hum possible but it is a cam that moves the motor plate up and down on the lever

 

[123hotchef]

I only finished 2 of these. I will finish the rest tomorrow.