screwcutting.

[qwakers]

hi guys.

im a bit cash strapped at the moment so although i would love to go buy another vice, im left with the only option being to repair what i have. and to be fair, its been a good vice for what it is bar one problem.

the leadscrew had a hole drilled through for a r pin (common as you know) and it has now snapped there twice.

rather than weld it together again, i was wondering if someone with a bit of free time and a lathe would do me a favour and make a new one?

total thread length needs to be 290mm and as i have no way of measuring a thread this course id post you the old lead screw to measure.

obviously it'd need a 'head' on the end of about 40mm long, say 30-50mm diameter.

can anyone help? im not expecting it to be free.

 

[slim_boy_fat]

can anyone help? im not expecting it to be free

@doubleboost might be your man for this, he did a great job for me when I was building my hydraulic press

 

[Kram]

Happy to try, it would be an interesting challenge, tho I dont have a tool that coarse.

Count the threads over an inch, looks like 4-8tpi Acme form, from the photo.

Is the nut removable?

 

[qwakers]

yes the nut is removable.

i measure it at 7tpi

 

[slimjim]

What vice is it off?

 

[qwakers]

a old chinese clone of a bad copy of a record.

 

[Kram]

If you can measure the screw OD, and would you be happy with 2TR (2mm pitch trapeziodal) screw and nut as I have the inserts for it. Thats roughly double the turns, should be stronger. If not, I can grind up a tool, but you'd need to send me the nut to test fit.

What do you want on the big end? Square flats, cross drill or plain round/knurled?

Interesting as it will use the full travel of lathe!

 

[gaz1]

it wouldnt be one of these by any chance

as i kinda broke the vice but nut and screw are fine and ive replaced the vice so the parts are mine

 

[qwakers]

If you can measure the screw OD, and would you be happy with 2TR (2mm pitch trapeziodal) screw and nut as I have the inserts for it. Thats roughly double the turns, should be stronger. If not, I can grind up a tool, but you'd need to send me the nut to test fit.

What do you want on the big end? Square flats, cross drill or plain round/knurled?

Interesting as it will use the full travel of lathe!

then end will be fine plain round, ill drill and fit a arm to it later.

ill have to get my digita calipers out ot measure the o/d , so bear with me on that one.

 

[qwakers]

it wouldnt be one of these by any chance

as i kinda broke the vice but nut and screw are fine and ive replaced the vice so the parts are mine

View attachment 225234 View attachment 225230 View attachment 225231

similar but not identical. doesnt mean i cant make it fit though!

 

[grim_d]

I'd also be happy to have a go at this if @Kram can't. It's all great practice.

 

[qwakers]

the o/d is indeed 12"

 

[Agroshield]

the o/d is indeed 12"

I think there is a typo. there. If the OD is 12", how big is your mouth using the table fork in the picture for scale?

 

[Pete.]

yes the nut is removable.

i measure it at 7tpi

If the thread length is 290mm that's likely a 4tpi screw going by the thread count.

 

[qwakers]

I think there is a typo. there. If the OD is 12", how big is your mouth using the table fork in the picture for scale?

yeah sorry, thats 1/2”

 

[qwakers]

no it is 7tpi, dont forget, its not complete in the pic, its snapped in two

 

[Kram]

I will have a another look at setting this up later but its beyond the lathe limits for my skills I need another 50-100mm bed length. Is anyone else is able to help with it?

 

[qwakers]

I'd also be happy to have a go at this if @Kram can't. It's all great practice.

you still up for this?

 

[grim_d]

Absolutely!

One thing though, it's not a multiple start thread is it?

 

[qwakers]

not as far as im aware...