‘Repairing’ badly scored dovetail slide surfaces

[Joseph Noci 1Participant @josephnoci1]

I tried to keep my shaper queries in one place, but that was a waste of time – lost down the page in the bog before one can blink – and few dig down the page it seems…So lets spread it around!

My shaper Ram slide ways are quite scored on the lower surface – the right side has the rear half quite bad, and the left side is very good. The scoring varies from barely detectable to maybe 0.4mm deep. Is there a reasonable way to help this along – fill with epoxy ( araldite made something called 'plastic steel' long ago) or some other material? Or should I just smooth it all nicely and ignore?

Joe

A good slide face on the column

The bad section on the ram base of the column.

The mating surface on the Ram underside

[Joseph Noci 1Participant @josephnoci1]

[SteveIParticipant @stevei]

Joe,

It looks like it has suffered from a combination of lack of oil, friction weld and tearing and probably some debris. Perhaps you could post some pictures which allow us to see the whole bearing ways?

The trouble with putting expoxy or other solutions is that they can come loose over time and cause more damage. A traditional solution would be to rebuild the ways via hand scraping. You could also consider to build them back up to original height with a way bearing material like turcite, however after gluing on the turcite would also need scraping in.

I would recommend to clean away all debris and make sure you can get lots of way oil to these bearings . I.e. nothing is blocked or broken. Then I would measure how it cuts. You might find it is good enough for you. If not rebuild it.

Good luck

Steve

[Joseph Noci 1Participant @josephnoci1]

Thanks Steve. I suspect lack of oil was the major culprit – the oil 'holes' were all well block with crud deep down.

It is difficult to photograph the whole way length while simultaneously providing decent resolution of the grooves – not sure how to do that. I am not sure how to scrape this either – the right way has a section of about 250mm ( the rear part) that is partly shown in the bad images, and that scoring is deep, up to 0.4mm in places, so a lot of scraping!

What also bothers me also are the oil distribution channels – there are three oil 'holes' per side, one forward, one rear and one about center of the ram slide length. The first photo in my post above shows a V shaped channel routed out in the base to take oil from the hole and spread it. This V channel is present in the rear and forward oil holes, both left and right slides, but NOT in the central oil hole – maybe that is why oil never got to the central part of the slide in the first place. However, the left slide is in very good condition, and also lacks this V channel…The damage is however done, but maybe I should route similar channels in the central hole area as well anyway.

Thank you for the test info page – is this general, or did this apply to a specific shaper or manufacturer?

regards

Joe

[SteveIParticipant @stevei]

Joe,

I think it is perfectly acceptable to add additional oil channels. After all if the oil does not completely cover the bearing way you will get wear. Some of these old tools can be improved, afterall they were built to a compromise and the wear patterns you see when you strip tools down don't lie. I use a carbide burr and the dremel for adding oil channels. When I get round to it my Elliot 10M needs some modification as it needs lots of oil on the ram and its a real pain to stop the job to squirt oil in as often as it needs it.

The test page is from George Schlesinger's book "testing machine tools". I've just sent you a private message.

Steve

[HopperParticipant @hopper]

.4mm is more than you would usually address with scraping. More often at that depth of damage you would machine it off then finish scrape it. Can you get it milled off flat at a machine shop locally down there?

But it would be worth, as suggested, to put it together as is, or after knocking the burrs off with a file, with proper lubrication and see how it works as it is. It might be good enough for what you want in the home shop.

Otherwise it's a major major job to scrape that sort of depth, keeping it straight, flat, parallel etc. And the unworn side would have to be brought down the same amount to keep the ram sitting level. If you go down that path, it would help to get a copy of Connelly's book "Machine Tool Reconditioning" as your bible.

[Ady1Participant @ady1]

Clean it up and run it would be my decision

The rough bits will hold oil in them

See how it goes… then make the big decisions

[PeteParticipant @pete41194]

Ignore it? It's your machine so any decisions are up to you of course. But visualise how the machine works and it's required alignments. With scoring that deep it was run for a very long time without oil. The previous owner should have been able to hear at least some changes and investigated a bit and long before it got that bad. The lack of oil dripping off the front of the one dovetail should have been a good clue as well. The one side of the ram is now running at a large misalignment which in turn misaligns the good dovetail side. The ram weight and cutting forces are now being shifted to a couple of very narrow areas on both the male and female dovetail on the good side. That will greatly accelerate wear and the problem can only get far worse. Shapers and the surface finish and accuracy they can produce can be fairly close to surface grinding with a good condition machine and properly sharpened tools. Any excess wear and misalignment in the machines movements will directly show up as a measureable amount on whatever part is being machined.At the barest minimum milling to get all 4 of the dovetail surfaces correct would help a great deal over what it is now. Surface grinding is much more accurate obviously and would be much better. Most machines today are only surface ground with some oil flaking such as the Bridgeports use. It's usually a very expensive industrial CNC or tool room machine before hand or power scrapeing is done on any of them today.

Since machine tool slides ride on an oil wedge having that center oil groove may not have been thought to be needed by the factory. Adding one certainly couldn't hurt. But there is NO easy, cheap, or fast way of fixing all that wear without at least milling on a very accurate and good condition industrial quality machine. Having it ground by a really good and experienced machine tool rebuilder would be the way I'd go if it were mine. That still depends on just how important the machine is to you and what your willing to invest into it. Hand scrapeing that amount of wear while still maintaining it's 3 dimensional alignments would take a very long time and take a great deal of experience and skill. The investment in the correct test and alignment tools to do so would be far more than having every one of the machines slide surfaces ground.

[Neil LickfoldParticipant @neillickfold44316]

You may want to change to an HP grease and grease it often. Grease is cheap and look at a 200 grade grease. Try and keep the swarf off the front edge as well.

[Joseph Noci 1Participant @josephnoci1]

'The previous owner should have been able to hear at least some changes and investigated a bit and long before it got that bad'

The Previous 'owner' was a Farmer..and had delusions of building Steam Trains…And Farmers here have as main tools of repair a Hammer, Monkey Wrench, pair of BIG pliers, a large screwdriver doing double duty as a chisel and a roll of wire…And they only 'fix' something when it breaks..

Re-machining the slides is not an options, so I have no choice but to wing it..

There is no milling machine, shaper or surface grinder in Namibia with the required daylight or capability to do this work properly, hence my query as to options. Namibia is a Tourist destination, with a population of around 2.6million people, around 1.4million being totally rural. Machine shops in Namibia do one of two things – they effect repairs for mining equipment ( oh, we also mine a lot or Uranium..) such as ore conveyors and drive gearboxes and they repair Ship and Oil Rig Hulls…The smaller shops skim Alternator brush rings and maybe car brake discs….

So, clean and smooth it up, improve the oiling, and see what it does.

Joe

[BazyleParticipant @bazyle]

The V grooves look too crude to be factory cut but might have been a good idea in the first year. However as with any small hole, like a chuck ding on a lathe slide, they trap swarf and hold it and it is that which causes the scoring. So oil grooves are ok but must be cleaned frequently. It only takes one chip of steel swarf to move around an cause many scores in softer cast iron.

The scored side will keep trying to trap swarf and sandy dust to add tot he scoring so I suggest leaving it but strip clean regularly and use total loss oil drip feed like an old Myford spindle.

[David Standing 1Participant @davidstanding1]

Posted by Joseph Noci 1 on 13/07/2017 08:07:08:

'The previous owner should have been able to hear at least some changes and investigated a bit and long before it got that bad'

The Previous 'owner' was a Farmer..and had delusions of building Steam Trains…And Farmers here have as main tools of repair a Hammer, Monkey Wrench, pair of BIG pliers, a large screwdriver doing double duty as a chisel and a roll of wire…And they only 'fix' something when it breaks..

Re-machining the slides is not an options, so I have no choice but to wing it..

There is no milling machine, shaper or surface grinder in Namibia with the required daylight or capability to do this work properly, hence my query as to options. Namibia is a Tourist destination, with a population of around 2.6million people, around 1.4million being totally rural. Machine shops in Namibia do one of two things – they effect repairs for mining equipment ( oh, we also mine a lot or Uranium..) such as ore conveyors and drive gearboxes and they repair Ship and Oil Rig Hulls…The smaller shops skim Alternator brush rings and maybe car brake discs….

So, clean and smooth it up, improve the oiling, and see what it does.

Joe

In a nutshell, yup!

It may eventually end up as a boat anchor, but nothing to lose by trying to get it going in the meantime (after fixing the dovetail, of course &nbsp.

[HopperParticipant @hopper]

I thought the absence of machine shop facilities might be the case in Namibia, hence the suggestion to see how she runs as is.

Alternatively, you might want to google around and look at Moglice. It's an epoxy-like substance used for repairing damaged ways on machine tools, including some pretty large ones with high loadings. It depends on how much your bad way is worn down. If the original surface is partly intact with many deep gouges in between the high points, you may be able to fill the gouges with Moglice. It is done by building a "dam" around the area, setting the job dead level then pouring on liquid Moglice and letting it set in position. Or possibly by troweling a thicker mixture on to the gouged areas, which probably would need more hand finishing of the hardened product. Or even by putting the ram in place, with a release agent in place, and pumping the Moglice into the gap with a grease gun or caulking gun etc through those oil holes.

Or, if the bad way is worn down past that point, which you will need to measure off the good way, it may require thin strips of Turcite to be glued into position. This often requires machining after fitting as strips are often too thick.

So, if the good way is good enough, you might be able to jury rig something machine tool reconditioners call a sled that runs up and down the good way and has a cutter mounted to it that can machine down the bad way. This can be as simple as a lathe tool bit mounted on a cross slide arrangment which is manually pushed up and down the good way while taking incremental cuts off the area to be machined. Or you could go as far as to make a sled with a milling cutter or a small toolpost grinder type attachment in place that is likewise run up and down by hand while taking small cuts.

If worst comes to worst, you could use the "good" way as a reference surface and file and scrape small areas at intervals along each way that are carefully brought down to a specified depth below the reference surface. Once these are set up, the whole way is then filed and scraped down to the reference areas and scraped flat to a surface plate and straight edge etc. Very painstaking work and very high skill level.

Edited By Hopper on 13/07/2017 11:18:24

Edited By Hopper on 13/07/2017 11:19:46

Edited By Hopper on 13/07/2017 11:21:26

Edited By Hopper on 13/07/2017 11:21:49

[John Stevenson 1Participant @johnstevenson1]

Good God man it’s only a shaper. Just trim it up with an angle grinder and flap wheel and use it.

[Ady1Participant @ady1]

Joe N.

John can be a bit feisty, but he's one of the most experienced people in here

John

If you have a peek at Joes album, wihich already has around 300 photos even though he's not been here long, it shows that he's one of those do-it-all-properly and make it look great kinda guys

Edited By Ady1 on 13/07/2017 15:19:38

[David Standing 1Participant @davidstanding1]

Ady

I think John's comment was tongue in cheek.

And, knowing Joe's workshop, I doubt there is anything as messy as an angle grinder or flap wheel in there

[Joseph Noci 1Participant @josephnoci1]

No Problem, Feisty is fine …Patience is a virtue, they say, so please be patient with me – I do try and do things properly and assume no harm in asking if there are those that know better..If they wish to smack me about the head, also ok, but I doubt an angle grinder will help much on slide surfaces…

I'll just crawl into my oil hole and get on with it!

Thanks!

Joe

[Neil WyattModerator @neilwyatt]

Me?

I'd slap on a bit of blue and see how much contact there actually is and if it is reasonably even across and along the slides.

My bodge?

Temporarily glue a strips of emery tape to one set of sliding surfaces and work the ram for a while flooding oil through.

Swap over the strips and repeat.

Then remove the strips and use some fine valve paste to lap the two surfaces.

Don't aim to remove all the scores, just to do the 20% of smoothing that will give 80% of the improvement by taking off the peaks.

Neil

[peak4Participant @peak4]

Never used Moglice, but "Belzona" might be worth investigating.

It's another epoxy/metal mix designed for sliding surfaces, such as building up rotating shafts or hydraulic rams.

The trouble might be getting it in small enough quantities, so it might be worthwhile contacting the makers to see if they export to anyone else in your neck of the woods, and approaching them with a couple of 35mm film containers.

It's often used for building up shafts on big machines, think quarries/mines etc.

 

Good Luck

Bill

Edited By peak4 on 13/07/2017 16:00:30

[Mick HenshallParticipant @mickhenshall99321]

My 8"Boxford ( just acquired ) has 2 oiling points on each side of the ram and oiling points on all other sides, there are no oil grooves on any of the slide surfaces and no evidence of scoring, there is plenty of oil along all slides, I treat all my machines like you would a loco ie before I use it I oil it. I don't want to start cutting oil grooves if I can help it. Is the scoring on the gib side or the other?

Mick

[Joseph Noci 1Participant @josephnoci1]

Hello Mick,

the bad scoring is on right, horizontal slide, the gib is on the left side

Joe

[Mick HenshallParticipant @mickhenshall99321]

If it was me I would make sure all oilways were clear, rub over the score marks gently with a fine oilstone to remove any burrs and fit felt keeplates to front of bed v slides to prevent swarf getting into the slides, and as someone mentioned the score marks will act to distribute the oil nicely, good luck Joe

Mick

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