Lathe halh nuts

Hello.

I have bought a pinnacle 918 hobby lathe, very accurate, but the half nuts have been worn so badly that theres no thread in them at all. I have ordered some new one from the supplier, but they can't tell me about delivery or anything, I was looking at the old worn ones which are made from aluminium and it accured to me maybe I could get these nuts made from cast iron or with a little help maybe make them myself.

Year of manufacture 1978

Anyone help!

Joe M

Hi Joe,
Have a look at the thread "Lead screw nuts" This should give you some ideas on how to make some new ones.

Les.

Hello Les.

I've just sent you a posting thanking you for your advice. I don't know if I pressed the wrong button or what happened. So I'll thank you again.

I've looked at the web sites which have given me some ideas and need to learn more about the processes.

Once again.

Thanks Les.

Joe M

Hello.

Can anyone give advice on good indexable turning tools with 15 / 16mm shanks suitable for small

pinnacle hobby lathe. reasonable prices.

Many thanks.

Joe M.

For your 918 lathe advice it's woth looking here: **LINK**

The 918 and 920 are virtually identical.

Russell.

Thanks Russell.

Food for thought.

Joe M

Hello. I'm still looking for hobby lathe half nuts for my Pinnacle hobby lathe.I'm going to have one last go at finding a manufacturer / supplier before making them myself. Some people have been kind in offering advice on how to repair them useing various compounds but the nut wall thickness is so small I feel it might not be strong enough to support the new inserts. Is it possible to find a good supplier at a reasonable price.

Any help would be appreciated.

Joe

I made one in T6 aluminium for my lathe, fine after about a year so far

If you're stuck make one from delrin then make an aluminium one with the delrin one

Improvise

A basic leadscrew nut is a doddle to make because it's exactly the same TPI as the leadscrew

I burned through two new ones in 12 months on my 3.5inch hobby lathe because they were made of what seems to be an extremely soft bronze

I presume this is to minimise leadscrew wear

Once you learn to make your own it's a doddle, you need never worry again

Edited By Ady1 on 31/10/2012 23:03:43

Thanks Ady.

Where would I get delrin from? and what is it? You advise making an aluminium set from the delrin,

How do I do that? Really interesting.. I'll consider anything, it's all new to me.

Thanks again.

Joe

Delrin is a trade name for one type of acetal plastic, Joe. Acetal is engineering plastic, used (for example) to make the change wheels for small Chinese lathes. It can be had from many of the places which sell metal to the hobby, and can be found on Ebay, too.

Here's a thread on making a nut from it "the easy way" link .

Andy

Thank you so much Andy. ( I think I spelt your name wrong the first time)

I'm going to have a good look over the weekend at the sizes and hopefully buy some Acetal to get

this job started. Im looking forward to this interesting task. Maybe I'll contact you for some advice.

kind Regards.

Joe.

Joe, it's just something I've seen on the Internet but never tried myself, so I can't really offer any advice. The only half nut I've ever made was in brass to fit a baby lathe which had a solid nut before, making the saddle a pain to wind along the bed.

That said, I doubt if making the thread will be the hardest bit. Each of your half nuts will have dovetails or something so they can slide in and out of engagement, and some sort of slots or pins to link up with the cam action lever which operates them. A milling machine may be needed to create the dovetails (or whatever).

Andy

As the 918/920 lathes are Emco Compact 8 clones, would the Emco parts not fit ?

Pro Machine Tools list both metric and inperial half nuts here :

http://www.emcomachinetools.co.uk/EnterShop/tabid/268/List/1/CategoryID/62/Level/a/Default.aspx?SortField=UnitCost+DESC%2cProductNumber

They also have a parts lsiting for the Compact 8 that shows a sketch of the parts.

HTH

Hello Nigel.

Thank you for trying to find the right parts for my Pinnacle hobby lathe. I have left a message with pro machine tools and I suspect I'll hear something tomorrow monday 5th. I did go on the Emco site and brought up various drawings of the half nuts, but there different to mine. There's have a slot cut down each side where lt looks like a retainer strip must locate, where the set I have are dovetailed.

Thank you for trying to help.

Thanks

Joe

The dovetails are fixed to the apron with a couple of screws so it should be relatively easy to make and fit the other type of guide. Easier than making new leadscrew nuts at least.

Russell;

Thank you for trying to find the right parts for my Pinnacle hobby lathe

Pinnacle is a brand name used by Excel Machine Tools, Coventry. When I was first investigating getting a small lathe for home use, the Excel Pinnacle 918 was one of the machines I considered. As it happened, I ended up with a Boxford CUD followed by a Super 7. But I have always liked the look of the Emco machines and have a Taiwanese FB2 clone milling machine.

http://www.excelmachinetools.co.uk/contact.html

Have you tried them directly ?

Regards,

Nigel B.

There's also the Grizzly G4000 lathe:

http://www.grizzly.com/products/9-x-19-Bench-Lathe/G4000

Check that one out.

BTW - the belt idler for headstock drive on the original Compact-8s have friction bearings, looks like the "clone" has improved roller bearings. I have bearings to re-do TWO Compact-8s, as the bearings (or, shafts) wear, and loud rattling occurs. I've fixed one once, now to try doing the rollers...

Another JohnS.

Hello Nigel.

I have been waiting for six months or more for information regarding the half nuts and I'm always fobbed off when I chase my order at Excel. The Emco does look strangly like the pinnacle. I checked the Half nuts drawing out on the web site and they are different, and maybe they could be altered / adjusted to fit my lathe eventually. Maybe thats the way to go if I cant get Acetal to work.

Thanks again.

Joe M

Hello John.

Thank you for the info and link to grizzly. I Checked the site just now. The G400 lathe looks exactly the same, in fact, I have the original instruction manual / service parts list for the pinnacle and it's exactly the same as the G400 on the grizzly web site, even the same part numbers are listed with identical drawings of the various components. I'm thinking, could this be the actual replacement parts. I'll contact them within this coming week and ask for actual half nut sizes to compare.

Thanks again.

Joe

Thanks Russell.

I have actually thought of maybe altering / adjusting Emco half nuts to suit my Pinnacle lathe. I am considering useing Acetal but worry the half nut wall thickness is so thin it might not be strong enough to support the acetal inserts, so this is a real possibility.

Joe