Thread: Is lathe bed grinding available in Brisbane? Any alternatives?

Pretty much as above - Is lathe bed grinding available in Brisbane? I just picked up an old big Hafco lathe with hardened ways which has seen wear and needs doing.

Are there any practical alternatives? I suspect I might even be able to scrape it as Hafco hardened does not necessarily mean super hard.
I have seen 'scraping' with a hand held die grinder in one youtube vid but have not seen much literature / instruction on it.

Hand scraping a hardened vee way bed would be an absolute bastard. How positive are you of bad wear, how much are we talking? A lathe is seriously tolerant of wear generally. I would advise really getting to know it before committing to anything.

I have seen pre scraping done with flap discs then a number of hand passes afterward, I don't think a die grinder is good for anything in this circumstance.

Originally Posted by caskwarrior

Hand scraping a hardened vee way bed would be an absolute bastard. How positive are you of bad wear, how much are we talking? A lathe is seriously tolerant of wear generally. I would advise really getting to know it before committing to anything.

I have seen pre scraping done with flap discs then a number of hand passes afterward, I don't think a die grinder is good for anything in this circumstance.

This is what I'm thinking - https://www.youtube.com/watch?v=YXLk0mJOwJM but I can't find more info.

Yes it has significant wear by all accounts, the bed needs fixing according to the previous owner who was honest with me. I got it for very little, but it would be a nice lathe if it was reconditioned.

edit - I wonder if you could just heat tread it to remove the hardened ways then scrape it normally. Or this - https://www.youtube.com/watch?v=VfxONqCa7WQ

A mate had his his Hercus reground it cost well over $1,000 make sure you Hafco is worth it

There is no one in Brisbane that advertises such a service is available.

I could do it for you for cheap, but freight costs might baulk you.

Just be warned that grinding the bed is the start of a huge rabbit warren of time you will spend to do a proper job. Took me three years to do the 10EE. The bed grinding was the quickest, although I was pretty picky with the rebuild.

Originally Posted by caskwarrior

I have seen pre scraping done with flap discs then a number of hand passes afterward, I don't think a die grinder is good for anything in this circumstance.

I've used a die grinder with a carbide burr to rough down a straight edge I'd machined with a nasty twist (which is what you get for machining a 1m long surface on a mill with 750mm of travel, necessitating a setup I didn't check well).

I don't recommend it but it does work. However it wasn't hardened.

There are a number of examples posted on PM where people have done this using a baby angle grinder, both electric & pneumatic, quite successfully. I was so impressed by the baby angle grinder that I bought one for future use. A 3" angle grinder is quite handy and less hassle than a pneumatic one of the same size.

RC's offer is the best way to go but he's correct about the rabbit hole. I've almost hit the bottom of my personal one. I think.

PDW

Thanks guys, and thanks for the offer .RC. BTW where are you .RC?

I will probably go the baby angle grinder route. What sort of disc to use though? I have done very very little angle grinding in my time.
I have been scraping a fair bit recently, up to about 20-30 hours + of experience, and I think I'm finally getting it. It reminds me of welding - easy to go wrong without knowing quite why.
Anyone got any ideas as to something I could practice 'grinding for flatness' on? Before taking to the ways (bit scary). A block with high hardness - I guess I could mill a rectangle then heat treat it myself. Would it have to be cast iron or just a high hardness though?

Here's the lathe in all her beauty, AL-340A.

Just to reiterate, you need to measure everything. Take plenty of photos and really map out where the wear is before you go bananas. Im assuming the bed is induction hardened cast iron rather than tool steel inserts?

I bought a new AL340 11 years ago and its a POS. Its functional and much better than having no lathe at all but its still a built-as-cheaply-as-possible POS. I'd be tempted to put the time and effort into scraping and rebuilding one of the classics like a Monarch but not an AL340. But that's just me, its your time your money etc.

That said, if you go ahead with the rebuild, one thing that comes to mind that you will presumably want to address is the manner in which headstock is connected to the bed on the AL340 and presumably most lathes of its ilk. This is part of the rabbit hole to which Richard referred.

The underside of the headstock is rough milled as is the bed where it sits. With the hold down bolts undone (4 x M10) the headstock actually rocks as it sits on the bed. Headstock alignment is carried out by selectively tweaking the 4 hold down bolts until the headstock is more or less pointing in the right direction. Some refer to this dreadful process as torque alignment, which makes it sound much better than it is. After you have the scraped the bed and headstock you will then of course need to consider the height of the tailstock.

I have the plate on the end of my AL340 that tells me that the ways are induction hardened, whether its true or not or just how hard is hard I have no idea.

Originally Posted by PDW

There are a number of examples posted on PM where people have done this using a baby angle grinder, both electric & pneumatic, quite successfully. I was so impressed by the baby angle grinder that I bought one for future use. A 3" angle grinder is quite handy and less hassle than a pneumatic one of the same size.
PDW

Out of interest what type of 3" electric angle grinder are you using? I've not seen these around in electric.

Originally Posted by Com_VC

Out of interest what type of 3" electric angle grinder are you using? I've not seen these around in electric.

Nor had I until a couple posts on PM had one of the members using one to 'hard scrape' a hardened lathe bed. At which point I decided I had to have one too.

Pretty gutless device but it works. I doubt I'll use it a lot but - shrug - how would that be different to a lot of other things I have tucked away.....

https://www.ebay.com.au/itm/Mini-Ele...72.m2749.l2649

Still looks handy to have around, I prefer to use electric over pneumatic when possible, less noise. What discs does it use, my pneumatic one uses these with a 10mm bore. https://www.ebay.com.au/itm/3-75mm-S...ZWF43KPFqRfvQw