5/8-18UNF on mini-lathe

[inonickname]

Threading on lathes is NOT easy.

Do some reading up on it, I find that some of the mini lathe enthusiast sites around have some of the best information for any turning operation. Having a foot break with it is excellent if you are cutting towards the chuck. When one of the screws on my lathe had become loosened off the tool bent a 20mm steel rod like plastic, shattering the carbide insert.

Taps and dies can simply be used with a handle that is supplied with the set, however for things that require a large degree of accuracy starting the tap or die with the lathe is a good idea. Most taps can be held in a drill chuck, though dies will need a custom holder for lathe use.

On a slightly off topic note, if you haven't really tooled up your lathe much consider carbide tools. The use out of a decent set (don't get a brazed crap set) is amazing. My set came with ten carbide inserts, each with three cutting edges (six if you count forwards + back). I'm on the first cutting bit, and haven't even rotated it. It's still razor sharp, and the lathe is used very often.

Though keeping some HSS inserts for better finishing and custom tools is a good idea.

[Demon]

Threading on lathes is NOT easy.

I am conscious of that.


In these carbide cutters, wich would be better quality?


http://www.harborfreight.com/cpi/ctaf/d ... mber=38886


http://www.harborfreight.com/cpi/ctaf/d ... mber=39931

And can i grind an hss blank to make a thread cutting tool? Or its too tricky to get the right angle?

[CS]

The brazed carbide cutters work for everything but steel. The shanks on them flex worse then any other lathe tool I've used. In all I would avoid them, even the boring variant.

I'd recommend the indexable tooling, like in the second link. Those are 1/4" square shank for $20, $5 more you can get a set with 1/2":

http://www.harborfreight.com/cpi/ctaf/D ... mber=39933

Own both the 1/4", and the 1/2" set. I'd recommend either.

You can grind HSS blanks for threading, they have jigs or you can use a grinder with a tilting table.

[jrrdw]

I like to use 5/16ths" X 2 1/2" HSS blanks. Bought 20 of them from Enco for .15c a piece. So far I've ground a o-ring groove cutter, a left hand cutter, a right hand cutter, and a straight cutter.

The only problem with using the 5/16th" squares is making that prefect shim for the tool post to get the center line. I'm a hair (.0001 approx) below so when I'm facing a work piece it leaves a tiny nub in the center, not a big deal.

By the way I have a Central Machinary 8 X 12 ordered from Harbor Freight. Most seem to get the 7 X 10.

[kenbo0422]

No matter which mini lathe you buy you're going to spend the first month (at least) tuning it up. You'll probably end up doing quite a bit to remove the runout, then you'll want to lap the surfaces on your cross slide and such. Out of the factory they're OK for some work, but nothing too precision. Get rid of the tool post, don't argue with me. Buy a quick change tool post from Little Machine Shop or elsewhere. They will allow you to adjust your tool height and set it, without shims. Buy your first set of 'specialty' cutting bits already ground and ready to go. Use them as a model to make your own from blanks. Visit 'minilathe.com' often. Join a yahoo group for the lathes. You'll learn more than you'll ever want to know from people who have been doing it for decades, they don't consider any question as 'stupid' and they don't mind going over a subject that has been covered before.

Inserts are fine for most straight work, but you will have to have your own special bits made (on your own grinding wheel) as someone here pointed out, 'to make O-ring grooves', etc. Your grinding wheel will need to be clean, flat and NOT offcenter. A diamond grinder dresser will work.

Just thought I would give you a head's up. The ride is worth it, though.

[Demon]

Thank you all for the support

I have this sort of grinder;
http://www.nmri.go.jp/eng/khirata/metal ... 01_big.jpg

Would it do the job if i get a diamond blade for it and a homemade holding rig to get it straight?

[jrrdw]

I use a bench grinder with a 600 grit stone and hold it by hand. Keep a cup of water close to keep the bit cool. Only takes a few trys to get them right. The more you pratice the easier it gets. I even sharpen my drill bits by hand on the same grinder and stone.

It will be hard to grind bits with that angle grinder. Just not ment to do that kind of work. I'm not saying it can't be done with that, but a bench grinder works better.

[ramses]

You will really want a bench grinder. They are available from harbor freight for around $40.00. A diamond dressing tool actually grinds the wheel to make it straight, square, and flat. I've heard they are less than $10.

[cannon monkey]

im confused but if ur tring to add a fitting to use a c02 tank it just 3/8 flared fitting

[Demon]

Look down the page

http://www.teamonslaught.fsnet.co.uk/co2_info.htm

What makes you say its 3/8 thread on a co2 paintball style tank?

If it is it would be much more simple...