Larry, I hadn't thought about that with grease. I've sprayed it with WD-40 for the time being. Maybe I'll just leave it at that for now.

I think, long term, I'll look to replace the current screw box with more suitable square or acme threads, but knowing where to get them is a sticking point, without cannabalising some existing existing tool.

I have access to a small metal lathe in my department at the school I work at, but I haven't turned threads on a large since I got my degree!

Anyway, hopefully I'll get the bench clamp well underway today! 

Cheers, 

Jono.

You could go with 3in1 light oil, irs about $3 at bunnings, thats what i use. 

At the same i dont think it makes much of a difference, ive been working in a machining workshop the last two weeks and the main screws on their lathes are to so greasy and covered in swarf and filings, it has had no ill effect. I think it is a possibility, but in reality I don't think its that important. Your threads are pretty thin though and it doesn't hurt to get light oil, but I wouldn't worry too much

Also just today I was thinking about how to turn acme threads and I asked my co-worker and he said without manually doing it, you'd need an adjustable gearbox for the spindle and feed screw. 

However, i came up with a solution. 

The main screw of the lathe would be acme, so you can use that as a reference. 

First you would wrap a square wire around the threads of the maimscrew-like how old screwboxes were made. You wouldn't need too much, probably an inch to 2 

Then you'd have the steel you plan on using for the screw and turn the whole thing down to size, then turn down the end of it even further so that the wire you have wrapped can fit on snug, then braze, solder or weld it on. This would essentially thread the end of the bar.

Repeating the wrapping you could use that as a "screwbox" and attach it to the back of the tool post, this means when the bar spins, it also moves the tool post and carriage forward. 

From there its just inserting a cutting piece ground to size, hss steel might be better than a carbide-gives sharp 90° corners rather than with a radius.

You would want the spindle speed extremely low, and depending on yhe carriage resistance you might have to apply slight pressure but the wound up wire would guide the cutting piece to duplicate the threads. If the second piece of wound wire doesn't work as a "screwbox" just a flat insert between the makeshift threads should also work.

I'd try it myself only th shop isnt open tmr, and I'm only working there for the holidays, so thats about it for me. 

The main issue I can think of is to remove the wire wrapping you would need the end of the lead screw exposed, or other acme threads to copy, like off another vise

Yeah, the lathe at school has back gears for the lead screw. I would just need to find the time to set the right feed and pitch. 

In the meantime, in today's episode: The maiden voyage! 

I was keen to get a lot done today because spending the day with my wife tomorrow and I'm in a fishing competition Saturday and Sunday and then I'm back to work.

I wasn't meaning to rush, but I did make some simple mistakes that will mean re-working a few things. 

The first part of the day was spent working on the bar for the bench clamp. I needed to drift the hole for the tenon again, then punch the undersized hole for the clamp thread then alternate the two bends around riveting the tenon in place. What actually happened was I got excited about riveting the tenon and did it before punching the second hole or making the first bend. This made the punching and bending much more awkward than they needed to be. Oh well, at least this one didn't cause any extra work to fix things. 

Then I had to go and buy some 12mm all thread and an M12 tap because none of my bolts had thread all the way to the head. I cheated a little bit and just stripped the galv off two M12 nuts and the end of the piece of all thread for the clamp with hydrochloric acid, neutralized them and then forge welded them to make a meatball/cylinder for the clamp handle. I ground a ball joint shape in the end of the thread and made a little clamp disc and drilled a hole in the back of it the same size as the maximum o.d. of the ball joint, then I heated it and ball punched it on around the back joint. 

Now what's wrong with this picture? 

... Yes. I assembled it without putting it in through the clamp! 

I had to heat it, knock it back off, put it through and re-punch it. Thankfully, it worked and still even swivels in the ball joint.

The last step was to drill through the screw for the clamp, put the handle in and then upset a ball on to the end. 

This just went all wrong. I got it in the end, but initially it upset on either side of the meatball, jammed, and then bent. I had to beat it back and forth, flatten it the bends, and file and grind the slight upset and marring on the handle shaft.

So, I got it together! I took it to the table for its maiden voyage. 

It works, but again, what's wrong with this picture: 

It's backwards!!!

It functions. It holds on the table well and it holds a work piece firmly, but I'll have to grind the rivet, grind that section of the clamp thinner and then turn it around and re-rivet it. Therein lies the challenge, my holidays are nearly done. I'll need to try to keep up some momentum to actually finish fixing the problems.

I took a video of the maiden voyage, too, for anyone who's interested. 

https://youtube.com/shorts/wAXlfYYl0Kc?si=hfAcbqE7vxPUFd7G

Cheers,

Jono.

Well done Jono! Kudos to you for sharing the mistakes (that we all make!) as encouragement to others to think better. I've found I need to "think thrice, measure twice, cut once" but I'll probably need to add a fourth step in there as well... I'm thinking with the amount of time and effort you have put into this project, you'll have some built in motivation and momentum to attend to the next steps, even though they won't happen as quickly once you're back at work.

--Larry

Jono, great job. Both in making a tool that works and in being able to use tools that you have made to assist in making another tool. That is awesome, mate. 

Jono, that is amazing!  You built a great tool.  Could you flip the screw box around instead of grinding and reriveting?   Or are the holes in each arm custom fit to the screw box parts?  

Very cool, Jono! Here's to the next one looking like this:

(This is the vise design that Thomas Latane uses in his vise making classes. You can see process pictures on his website.)

Thanks for the comments everyone! 

You know, Brian, I didn't even think of that until you pointed it out! But yes, they are slightly different sizes and the one side has a slight key slot sort of shape for the outer thread of the screw box. Also the hinge plates only go the one way so it would feel a bit weird to have the jaw open away from the screw handle.

Today, I managed to get back to it and fix up the backwards assembly. I had a bit of trouble when I ground off the tenon/rivet. I got a bit gung-ho on the heave-ho and sheared the tenon off when I tried to twist it. At least that made it easy to punch out backwards. Then I ground it down a little, welded it back on and then plug welded it into the existing hole in the clamp assembly.

And a video in summary:

 

Thanks to everyone who has followed along and thanks for all the supportive comments!

I'll keep an eye on this thread and chip in every now and then with review updates, especially if I get an acme thread or square thread for it.

Cheers,

Jono.