Thread: Hercus 9" bed worn

Thanks for reminding me. I asked my local branch to get in on loan six months ago. Nothing so far- I may have to try again, harder.

Does inter-library loan always work with universities?

Greg

Should do unless it has been put on special reserve (ie set aside for student use in the library without the right to borrow).

Has anyone used Moglice? I read it can be mixed as a putty applied then scraped in an hour.
My Hercus bed has wear on the front and back ^ sections that take the saddle but the inside ^ that takes the tail stock is fine. I was reading about scraping but sounded hard work and could change heights and angles.
The ^'s are only worn in the middle there is a ridge on the top and the bottom so I was thinking if this was filled with Moglice putty (perhaps the saddle aswell) then scraped it would be back to original. This way the head stock and tail stock would not need to be realined as it would if the whole bed was reground.
I wanted to know if this was possible or am I talking crap?

Thanks for help everyone its a big learning curve for me, as I didn't even know the names for most bits of a lathe so it was difficult to follow advice. Now I have a manual from Bitza500 and have seen how to strip bits off. My cross slide is fine after a clean and tighten.

In a word: No.

I'm sorry to dash your hopes, but there are no short cuts (and I have been looking for them all of my life) in this. The ways themselves are not suitable for moglice, which is pretty soft (relatively). It would not be durable, nor would it resist chips and it would probably peel off.

The proper way is to grind the beds, then scrape for bearing if desired (it is better than a freshly ground surface). The saddle needs to be ground then scraped to fit the ways again. Moglice or turcite (or garlock if you can find any) is used to raise the level of the saddle to where it was originally, thus preserving the relationship of the rack and leadscrew to the apron.

If the grind job is done well the headstock and tailstock alignment shouldn't change vertically. You will need to re-establish perfect co-axial positioning when you put it all back together anyway.

Oilers in the saddle and good way wipers would be a modification that I'd do to a Hercus saddle to delay wear from developing next time. Plus it's a better repair to improve things whenever you can.

Greg

BTW...proper scraping tools cost much more than a Hercus bed grind job.

I have come to learn that hand scraping is not a trivial skill, nor a quick process. Good luck with your restoration.

The topic of Moglice and Turcite is probably worth a bit of a discussion..

Moglice is a putty epoxy, You mix it up then apply it as a liquid form onto milled ways...You mill the ways to make them rough to the Moglice sticks..Of course you need a releasing agent on the opposite way so it does not stick to it.

Once cured it does not need scraping to fit but instead needs scraping to lower the amount of contact..As when initially done the saddle will have 100% bearing surface on the way..This needs to be broken up to about 60% to reduce slip stick...Slip stick is when you try to move a stationery saddle but frictional forces oppose movement making initial movement jerky.. scraping also creates small pockets in the moglice to hold minute amounts of lubricant to help movement.

Turcite on the other hand comes in strips of solid material...You machine the slide needing building up and then you buy i the appropriate thickness of Turcite...You glue it on then fit and scrape the way...

Another material that can be used to build up a worn way is metal spraying..This is by far the best way, but the most expensive way to do it...

Is Turcite expensive? Greg, when you say good way wipers, are these a commercial item?

Australian machinery reconditioners seem to be a bit light on the ground - a Google search did not provide anything useful at all. However, I then remembered seeing an ad. in Australian Model Engineering magazine for machine tool reconditioning including slideway grinding. There is no website or e-mail address, but contact information given in the ad. is:

"Discuss repair options with Harry at the MTA factory,
No 2 By the Sea Road,
MONA VALE , NSW 2013
Phone 02 99794866 Fax 02 99794856"

The above quote was put in by Steve (Blackfrancis). I rang them he seemed very helpful to grind bed and saddle and pack saddle shim rack in the $300 range. He said they do hobby jobs between proper jobs. He said the tail stock will need shimming aswell.

Sounds like a good deal to me Glenn

That sounds like an incredible deal to me. Thanks for reporting back.

Re: Turcite costs. I don't know. I found a local machinery rebuilder who told me he'd help me out when I'm ready to re-do my saddle but we didn't discuss price. Last year I attempted to buy some moglice from a US dealer but my enquiry got kicked to the German head office. Shipping becomes a big deal because being epoxy its a hazardous material and air freight goes up dramatically. I think it was a couple hundred shipping for their smallest package.

I am going to a scraping class in Seattle soon, I plan to investigate further. I have a dangerous goods shipper certificate, so maybe I can ship it back to myself cheaply. We'll see. If so I'll get enough to share.

Greg

The course sounds great Greg. How long will you spend over there?

Any thoughts on way wipers? That's something I'd like to improve on my lathe, but not sure how to go about it.

Cheers
Steve

Sorry Steve, that's the question that I meant to answer. For guidance on that I think I'd be haunting the South Bend forums. I'll look for a link for you. Basically it's just a piece of felt held in place with a sheet metal cover. Heavy felt is around at the fabric discounters, but you may have some luck finding the real machine stuff.

The idea is of course to exclude the swarf from getting caught between the saddle and ways. Some industrial machines also have a miniature section of windshield wiper blade, but to my thinking that would tend to also clean the oil from the ways...not a great thing.

I'll try to post some photos when time permits...I do a hit and run on the computer every few hours between chores.

The course is two days, a basics only thing, but enough to correct any technique errors that I've taught myself. Since I had some "use it or lose it" tickets I thought I'd jump at the chance. Kind of a bizarre way to spend days off, and a long way to go to do it, but then again I used to commute from California to Toronto years ago. I wish I didn't hate flying so much.

Greg


Stop press! I just found this felt on ebay...it's what I use. Good stuff ebay item 320335826966

...and this: 300246828076

Thanks Greg. I have the original felt wipers on my machine but the felt definitely needs replacing. I made wipers for the tailstock, just using hat felt. This looks like a much better option.

I think the scraping course sounds like a great thing. There can't be many people around that can hand recondition a machine tool these days. One of the things I like about my lathe is that when I bought it, it had just been reconditioned by an old expert. Having a completely hand scraped machine that is still very accurate is a bit out of the ordinary these days. I like the historical connection of how without hand scraping we wouldn't have accurate machine tools.

Steve

I can fly a biplane and drive a steam tractor, but this seems like an old fashioned skill that's actually useful. Of course many modern machines run on linear bearings, but I'm told that there are a few scraping hands still employed here and there.

I know that they used to scrape in mating flanges for high pressure steam. I wonder if they still do that for power stations and the like?

I happen to be a bottom feeder when it comes to machines and cling to the belief that I can afford an old machine and fix it a lot easier than buying new*.

Everything I know about the physical world comes from being a cheapskate and learning how to fix junk cars, airplanes, boats and now machine tools.

Greg.

I'll do a new thread on the class when I return in early March. (I'm only going over for a few days at the end of the month)

Sounds great Greg

I look forward to your thread

Steve