I'm with Brian on this one Lee.

By all means give the ram a deep clean, change the felts and (re)adjust the gibs but then see how she runs. You don't mention what make/model your shaper is but these were generally machines made to do hard work and they had long life almost built in. I wouldn't do anything too drastic until I had very good evidence it was required.

Regards,

IanT

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Lee,

Regarding your specific question … If the ways and the gib-strip are apparently all good and true, but the ram is still rubbing, then you should be able to effect some improvement with a scraper and/or careful use of a slipstone.

BUT this is a big chunk of metal to work on, especially if this is your first attempt, and it would be very easy to make things worse rather than better.

When you are absolutely certain that the vees are spotlessly clean, have a very good look at the gib-strip and its adjusters before you go any further. … In my limited experience; poorly engineered gib-strip adjustment is a common source of trouble. [Geo. H. Thomas has described the problem and its cure in some detail]

If there is visible ["daylight under a straightedge"] wear, then the vees will probably need truing, by filing or machining, before you bother with a scraper.

MichaelG.

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P.S. This thread is worth reading.

Also, this page.

Edited By Michael Gilligan on 22/07/2014 08:20:02

Edited By Michael Gilligan on 22/07/2014 08:34:16

Edited By Michael Gilligan on 22/07/2014 08:35:36

Hello Steve,

I think you have put across all the points that matter on the subject of scraping with both clarity and precision, it is NOT a trivial matter as you so succintly describe.

My one venture into that art form was to scrape a surface plate referencing back to an Inspection grade plate for comparison and revealing the high spots as I went. I don't suppose for one moment I got a point score anywhere near those you describe!

Lee may have much more experience than he lets on; scraping triangular machine tool ways is another level of skill above getting things flat.

I would be looking for all the excuses I could find to avoid inflicting my amateur efforts on my own Elloit 10M.

As Ian T observed earlier, they are rugged machines built for hard work and maintaining the squareness to the table ways would be an added challenge, in addition to dealing with the ram and it's guide.

Regards Brian

lee,

I didn't mean to put you off. I just tried to explain that based on my first tentative steps into scraping the major lesson is you need to be very careful and methodical about this. From the internet accounts plenty "amateurs" do this and do it well. Some ruin there machines. It is my hope that I can bring my machines back to factory tolerances. I am guessing that with the experience you have you are set on returning it to the factory specification and deep down a paint job and clean wont cut it. I am cursed with the same mind set.

I took a quick look at the ways on my 10m ram. They are a scraped surface, with some wear. I am surprised you are seeing machining marks. From your description of the wear it sounds to me like you have a small but critically important job to do in cleaning out the lubrication delivery to the ram if you have not already done so.

From the time cleaning and observing all my second hand clapped out machine tools here is one rule of thumb, if the means to deliver way oil is blocked those bearing surfaces will be heavily worn. Especially so if they are different. E.g. my bridgeport mill which has some of the surfaces chromed and some cast iron. where the one shot lub lines were blocked or damaged the chromed ways are hardly worn and the cast iron is heavily worn, that is compounded by the problem of how to scrape the chromed ways. The under side of my mills saddle is like a ploughed field, and of course it is not possible to see that until you take the saddle off. I wish I had known/thought that dependency through before I purchased. Having said that I will scrape what I can and then see where I am.

Another option if you have heavy wear is to machine the ram down. Then epoxy turcite (or equivalent) and then scrape that in. There are some good youtube videos on that. I am considering that on the underside of my mills saddle since that brings me back up to the factory dimensions. If I decide to do that I'll be practicing on scrap metal first.

Good luck and whether you scrape or not please post the progress. Also if someone has the knowledge and experience of the tolerances for a shaper please post them! If anyone is inclined to run a scraping course please let me know.

Lee, your problem may be in the gib adjustement rather than excessive wear on the ram and/or ways.

Usual way to adjust a gib is to clean and lub everything first, checking gib for nicks and burrs all over, paying special attention to the holes the adjusting screws go into. Then reassemble. First you back off all the gib screws and screw down the two end screws (one at each end) until they just kiss metal.

Slide the ram back and forth and keep adjusting the two end screws until you get nice free movement without slop. Yes a slightly worn way may be a shade tighter at the ends than in the middle but most often a reasonalble compromise can be found. When you have those two screws the best you can get them, nip up their locknuts (and check again to make sure locknuts have not changed the setting of the screws.

Then, when the two end screws are set, you bring the other screws in until they just kiss the gib strip but do not exert any further pressure on it. Check gib movement again and back out any tight middle screws by a bee's whisker (that's about half a hare's breath) and nip up the lock nuts, checking again the lock nuts have not changed the tension on the screws. A tight-fitting screwdriver that holds the screw very steady while nipping up the locknut is a must. A tappet adjusting tool even better. (Has a T handle on the screwdriver part that shows up any small movement of the screw.)

Certainly worth fiddling about with before doing anything drastic to the ways etc.

PS (Edit) Also check the state of the ends of the gib adjust screws and spin them in lathe and clean them up if uneven, worn or burred. That way, the turning of the screw will exert consistently increasing pressure on the gib strip. Burrs or wear on the ends of the screws (or the holes in the gib they go into) can lead to problems like you describe where it seems impossible to adjust them consistently due to the high and low spots on the end of the screw.

Edited By Hopper on 23/07/2014 06:22:50

Edited By Hopper on 23/07/2014 06:27:33

Edited By Hopper on 23/07/2014 06:30:46

Lee,

http://www.neme-s.org is a great site.

Again I am a novice. However if you machine the bearing surfaces to a high standard. What space is there left for the way oil? Wouldn't this result in more wear? Wouldn't you also get "stick-slip" from too much bearing contact?

If you leave the gib loose and have space for the oil you'll have a problem with the accuracy of the machine. My (novice) understanding is that bearing surfaces are scraped to provide recess for the oil with a tight gib and to avoid stick-slip to reduce the friction.

One thing we haven't mentioned is "flaking", from my Michael Morgan book "Basic Scraping Modern Methods":

Flaking – is a surface treatment given to ways and other bearing surfaces on a machine for the purposes of providing improved distribution and retention of lubrication and to to reduce the amount of bearing contact……"

Perhaps someone could educate me here, what is the modern machined way to create a bearing surface? Machined then flaked?

Steve

Lee,

Thats hopefully good news. At the risk of answering my own question and in case your interested take a look at the attached picture hopefully its readable. Its Dr Schlesinger's permissible errors when testing shaping machines.

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Excellent news, Lee:

Thanks for sharing … Lesson for the day.

MichaelG.