Member postings for colin hamilton

So I got a crawford trugrip chuck bundled with my lathe but it didnt come with any collets. After a bit of searching it seems that some people machine a new inner collar so the more widly available 5C collets can be used.

So this sounds like an ideal opportunity to use my lathe to make something for my lathe!

So my research would suggest the external thread on the 5C collet is a 1.238 x 20 tpi thread. But I'm have no idea would to do with this to get to the dimensions I need to establish (major and minor?) Before I start cutting the thread.

Any help would be appreciated.

Cheers

Colin

Thanks everyone. Sounds like I've started my down selection, needs a quill.

Cheers

Colin

Just trying to settle on what make of vertical milling machine I would like so have been doing some reading. I notice that not all vertical mills have a quill feed. How much of an issue is this for the model engineer? If I have power feed on the vertical axis is it even needed?

Thanks

Colin

David - thanks for the detailed response

Just back from trying out my new lathe tools. The turning tools in my first picture are ground to a sharp point. Can I put a bit of a round nose on it or does the chipbreaker groove mean this isnt sensible.

Thanks for the replies

Ive just got my first set of hss lathe tools and have a couple of very noddy questions.

It comes with a right and left handed turning tools. They have a groove ground into them. When mounting the tool does they groove go on the top or leading face? It looks, to me, like they would cut in either orientation. Photos below:

And what is this for?

Thanks

Colin

Thanks for the input. Mk 2 in EN8 - much better!!

Edited By colin hamilton on 03/10/2021 19:52:14

Now that is good advice 😀😀😀😃

So I'm going to have another go at making the chuck key this weekend. I've got myself a length of EN40b and EN8 and was going to make one from each (for practise). I'm using HSS tooling. Is there anything specific that I need to consider now I'm using these specific grades? Also as I dont have a mill will I still be able to file the square end?

Great advice, I had mixed up my 30 & 60 degrees. I followed Chris's no calculation method (above) and it worked out fantastically. I really like the fact that I dont need to remember where I got to, just keep cutting until the top slide gets back to zero. I think it's going to be my 'standard's method.

It went so well I've decided to make a new arbour for my table saw. Next thread is a 5/8 11tpi left handed thread; what could possibly go wrong!!

I did use larger diameter stock (25mm). Since I hand cut the square I'm wondering if I was a bit undersized and combined with the center drill just didnt leave enough stock. This is the before photo. I'll add one of the damage tomorrow.

So I'm just getting back into machining. The first thing I made was a chuck key for my 4 jaw. It isnt very big and the square end of the key is only 7mm across the flats. I forgot to leave additional length so the available material in the square end is reduced by the centre drill. I made it out of black mild steel from my local steel supplier. I used it today and the square end just twisted into a spiral.

Should I be using a specific grade of steel or do I need to do something to it after machining to make it suitable in this application?

Thanks everyone, I was getting confused between 60 and 30 degrees. I reset the angle to 60.5 and followed Chris suggestion for a no calculation method and it worked fantastically.

I was so enthused I've moved onto making a new arbour for my table saw so I've started on a 5/8 11tpi witworth for my second screw attempt. What could go wrong!!

When I used to work offshore, practises were still dominated by American custom so most things were imperial. We had to measure the drill pipe and sum all the individual lengths up. To make it easier they decimalsed the feet, so a foot had 10 (long) inches in it. We were issued with specially made tape measures!

Thanks for the input and video. I didnt realise there could be an issue with setting 30 or 60 degrees. I'll be checkingvtgat next.

Tony and Bazyle - I think you have hit the nail on the head operator error. Not sure where but I'm going to buy a hss thread cutting tool and at least that will remove one (big) variable - my grinding!

Thanks for the pointer