Member postings for Pete Rimmer

I wasn't referring to the particular one in the ARC link just that frame squares in general are made perpendicular on all sides close enough that they come fitted with an insulator for handling them lest you heat the top edge and push them out of square with heat from your hand.

Now that the class of machine has become apparent I guess it's all immaterial since it's not a very rigid design anyway.

Frame squares have all four sides finished perpendicular to each other. They are very versatile for doing alignment work.

By precision square I mean one of these type of things. I don't know your location but if you were near to me in Kent I could loan you mine.

Arceuro do one that is claimed to be 4 arc seconds, which is plenty good enough for what you need.

Edited By Pete Rimmer on 01/12/2018 19:22:25

Buy or borrow a decent precision square. The top and sides are perfectly square to each other and it will have a sensitive bubble with graduations. You can set the square on the table, against the column ways, against the mount for the head etc and compare measurements. The graduations will tell you how far out any surface is.

Could be that they machined the top surface and tee slots first then used those to mount the slide inverted to machine the bottom and vee ways.

How about grinding down some spent carbide milling/turning tips? They are quite heavy for the size.

That cross slide is badly warped. It's not sitting on the ways properly and the tee slots are all skewed. Even if you're past your warranty I would raise it as an issue with the retailer.

I don't blame you for not wanting to grind the bed, it's quite expensive and now that Brian's retired I don't know who else I'd take it to. For sure though I would give serious consideration to working over the cross slide and compound ways. I don;t think I've ever seen a used lathe more than a few years old that didn't need some kind of attention to the minor ways.

South Bend wicks are much larger than 1/4" Either 7/16" or 1/2" I didn't measure mine but they are quite fat with a spring around them.

You can't turn the taper with the compound? That's a pretty steep taper with a set-over and tapered inside and out makes it worse to hold. I'd drill some 1.5" stock 19mm and then turn the inside taper until the outboard ID is 32mm then repeat it on the outside taper with the same angle setup. Part off and de-burr to finish.

Steve Wells' website is pretty much the go-to repository for South Bend info and literature.

http://www.wswells.com/

How much of a refurbishment are you doing? I'm currently renovating a Heavy 10. Bed and saddle re-ground, all the other ways re-scraped. Full strip and rebuild of the rest of the mechanicals and of course re-painted all over.

Edited By Pete Rimmer on 25/11/2018 11:55:06

I can't see any reason why you would be unhappy with that Robin. Looks perfectly good to me.

The whole reason that a hand reamer has a long taper is to prevent the thing you're worried about, but if you're using the reamer in a machine either powered of hand-turned, buy machine reamers.

The CVA/Monarch lathe comes with a threading stop built-in. It allows two turns of the cross slide for fast retraction then 2 turns in again to meet the same mark. Advancing the tool into the cut is done by swinging the top slide around.

The older ones with plain bearings used a wick-fed system to keep oil flowing to the spindle. The oil was flung up into a reservoir and drained down a gallery to the wicks. These type won't turn as freely as the bearing spindle types and they will be heavier to turn until they have been warmed up before use.

Use back gear and make sure you have a good grip on the part.Turn the part slow and take a healthy cut.

You have it right Bill the diamonds (or CBN) are held in a binding matrix which should erode at a slow rate to expose fresh cutting edges as the erosion releases worn-out diamonds. The make-up of the binder determines the 'hardness' of the wheel and the size and density of the abrasive medium gives the wheel various other characteristics.

Some wheels do not erode because the diamonds are electro-plated onto a metal carrier, but the aluminium wheels with the brownish-coloured cutting edges certainly can be dressed.

John Rudd, you can use various methods to hold an ally part for surface grinding, just as you can actually surface grind aluminium, brass, 300-series stainless etc. Or you could simply bolt it to the table through the centre hole.

I read somewhere of a guy who used a green wheel on his surface grinder to true the face of his CBN wheel.

I've no idea of your economic situation Sam, you didn't say. When you said you'd asked lots of divers I presumed that they were at least somewhat professional ones. A proper outfit could do it but you're right they are in no way cheap, quite the opposite.

Find better divers. I had guys working at 24 metres down rigging up a concrete cutting setup in zero viz by touch alone. If I told them that it was impossible to attach a chain in zero viz they would fall over backwards laughing.

https://www.dropbox.com/s/fjvd2154o6cg4lo/divers.jpg

Edited By Pete Rimmer on 14/11/2018 22:17:28

Edited By Pete Rimmer on 14/11/2018 22:18:46