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When should you consider something other than Turcite for a wear surface

CBlair

Diamond
Joined
Sep 23, 2002
Location
Lawrenceville GA USA
We speak often of using Turcite, Rulon or some other plastic for replacing worn wear surfaces on machine tools. However, a recent discussion on Phenolic brought out an interesting point. Some machines because of the loads they are under are not good candidates for using these plastics and something harder or stiffer may be needed.

My question for those who are experienced is under what conditions or what machines or machine types should you not use Turcite? Or to put it another way, if Turcite is acceptable for milling machine tables and lathe carriages, then what kind of machines or loads should you stick to just scraping the original cast iron or use something other than Turcite or like products?


Charles
 

Other Brother

Hot Rolled
Joined
Dec 6, 2014
I was asked this recently as a customer spent $8000 to have all new turcite installed on a 35 year old VMC. The problem of installing something harder than turcite you risk wearing the hardened ways and then you are done. I had to replace every lube line on this machine due to plugged or broken lines. I believe that the turcite would still be good after 35 years had it been getting lube and the gibs were adjusted properly.

The best alternative design for heavy weight bearing surfaces I have seen is that of the old Okuma MC-500. The x-axis box ways support the x-axis, b-axis turntable and a huge tombstone, and I am guessing around 5000 pounds? After removing the back plates(keeper plates) and the ballscrew the slide moved when you leaned on it. I was amazed at what little force it took to slide it. Okuma used roller bearings on the weight bearing surface and turcite on the back plates and gibs. If I had a machine that had heavy loads I would look into a roller bearing set-up like that.

The heart and soul of all machines is a healthy and clean lube system.

Daryl
 

dian

Titanium
Joined
Feb 22, 2010
Location
ch
how many bearings? i always thought sliding ways were best for heavy loads. what about damping?
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
I am going to write an ongoing reply as i have some things to do around the house, as the spring weather is something, plus i am headed out of the country on Friday.

I thought I would start with a name product of a material as this is what My Dad and i used when we needed the material as it has a great and long lasting reputation of quality. http://www.ampcometal.com/documents/datasheets/ampco_alloy_brochure.pdf

We used to rebuild a lot of punch presses in the early days. My Dad especially worked for Huot in Saint Paul who made and still make tool boxes and North Star Steel a big punch press house in Minneapolis. I can recall being in my late teens scraping ball sockets, crank shaft bearings, caps, Rams and hold downs. Back then that's what was used as wear-strips. (more later on why).

On the bearing throws, ball sockets and bearing bushings we bought Amco 8 shaft and for the ways, hold downs and gibs we used Amco 18 plate. In the link i attached they explain the chemical mixtures and what and why it is used for. I don't want to get into that technical stuff as some love to bloviate on that. When we used it we would always rough scrape to 2 to 5 PPI and flat before we epoxy glued it to the ways plus we would drill, tap and countersink holes in it so we would also bolt it on.

Manytimes we were replacing the bronze as it came that way from the new machine builders and wore out. A punch press is a simple machine and the way systems are simple double v's or box ways. The Ram needs to be scraped square to the bottom and aligned to the bolster plate. It is tough and can be machined and scraped. I was just talking yesterday about Timesavers Lapping compound and where I saw it used one time was with a Bliss factory Tech that was working on a large press in the GE Plant in MPLS. The press needed a new crankshaft bearing. We were hired to assist the guy and instead of scraping the bearing and cap to the crank, he mixed up the yellow lapping compound, put on the cap loosely and ran the machine for a while..added some more compound, tightened the cap until it was tight and lapped in the bearing. Then cleaned it, scraped in oil pockets, ground in oil grooves and put it together.

We also used Amco 18 on G&L and Lucus Horizontal Boring Bars saddle ways and gibs, I have also used Nylatron on a Bullard HBB too. One doesn't see Bullard Horizontal Bars to often, but they exist.

The first time I saw Turcite was when I was a contractor at Midwestern Machinery (MWM) in MPLS. My Dad, brother and I were there rebuilding all kinds of machines and using bronze and Phenolic wear-strips. MWM sold a Gleason Curvic coupling grinder to Garrett Aero-Space in Phoenix and I flew down there so they could show me how to install Turcite and scrape it. They were buying new machines from Gleason and installing Turcite on the ways. They explained the reason they did that was because when the original cast iron box ways needed .001" clearance for the oil film to lubricate the ways. But when they indexed the part and the locking pin (lever) engaged the vibration would sometimes move the saddle over the .001" clearance and ruin the curvic coupling they were grinding. I have other instances of using it and Moglice I will share later. Rich
 

Other Brother

Hot Rolled
Joined
Dec 6, 2014
There were 8 bearings on the MC-500H x-axis. It was an old machine, early 90's vintage and had the original bearings. I think the speed of the rapid moves probably had something to do with the design to use bearings.
 

gbent

Diamond
Joined
Mar 14, 2005
Location
Kansas
I had been told by a couple of different CNC machine tool engineers the reason they went to turcite was the difference between static and dynamic friction is the smallest of any of the suitable bearing surfaces.

As for the roller packs for the axis ways, they are wonderful for minimal friction. The way wipers create greater drag than the bearings. I have worked on Sundstrand NC machines with rollerpacs. They never used rollerpacs with opposing keepers, but always with opposing rollerpacs. ISTR the pacs were loaded to .0002 preload. A horizontal had about a 5,000# table and I could push it by hand even with the way wipers installed. A big drawback is the rollerpacs required mist lube for waylube.
 

cash

Titanium
Joined
Aug 8, 2007
Location
Greendale,WI
If it is in a harsh environment, i.e. grinding or fine chips can get in I would stay away from turcite.

When possible and the machine can handle it, go cast iron to cast iron.

But every application is different and sometimes it is only by trial and error that you learn what you can use.

Remember that magic black stuff called Moglice that was going to solve all our problems.........

It is fun to chip off, that is about it.
 

RC99

Diamond
Joined
Mar 26, 2005
Location
near Rockhampton, Queensland, Australia
As for the roller packs for the axis ways, they are wonderful for minimal friction. The way wipers create greater drag than the bearings. I have worked on Sundstrand NC machines with rollerpacs. They never used rollerpacs with opposing keepers, but always with opposing rollerpacs. ISTR the pacs were loaded to .0002 preload. A horizontal had about a 5,000# table and I could push it by hand even with the way wipers installed. A big drawback is the rollerpacs required mist lube for waylube.

Roller ways suffer from reduced dynamic stiffness, they are just not as stiff as a sliding cast iron ways.... No doubt with modern computer design it can be got around...
 

ironsmith89

Aluminum
Joined
Aug 29, 2014
Location
lennox, sd, USA
Last month we rebuilt the heads of a gray planer at work, and used aluminum bronze in the saddles of the two upper heads. These are usually under huge compressive forces when planing and we've just never felt turcite could stay put as it does squish a bit. Turcite is wonderful stuff if it's applied and scraped properly, in my experience it needs to be scraped deeply, say .002 deep scraping. I usually pull scrape with a 1" radius, to achieve this. I have had to fix machines where the turcite was too smooth and it wrings onto it's opposing surface pretty tightly and causes drag. It's really amazing how something so slippery can be so sticky but its the vacuum created that causes the problem. I like aluminum bronze for high load applications.
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
About a year ago I wrote a thread about a Taiwanese Machine a fellow bought out in NJ I think and the Y axis had Stick Slip. I wrote how YCM / Supermax had the same issue at the factory and I showed them the were not scraping the low spots deep enough. Plus another issue is the oil grooves should be cut in a XXXX or <>l<>l<> diamond pattern. Many of the old designs use straight grooves l-----l-------l which will not let the oil spread out. think of the turcite as a seal and if it squishes down a little and the scrape marks are .0002'' deep the oil can not escape the oil groove. That's why i recommend .002" at a minimum scrape depth. Another thing to remember is if you cut or drill oil holes in the metal the Turcite moves against be sure to chamfer those holes a lot because if you leave them sharp it will shave the turcite off as it slides over it.

It doesn't take long for .0002" scrape marks to wear away and get stick slip.

One very important thing to do when scraping turcite, Rulon and even cast on cast. Lower the middle of the short surface lower then the high spots .001 to.002" so the way always has a puddle of oil laying there waiting to be spread out. This is very important if your using a cyclic oil pump as the machine may stop and the ways might be dry because the pump hasn't pumped for a while and you do a rapid move. You can see if there is a low spot with oil laying there it has immediate oil wedge.
Rich
 

CBlair

Diamond
Joined
Sep 23, 2002
Location
Lawrenceville GA USA
So what kind of machines are not good candidates for Turcite? We just heard about the heads on the planer, and it was said that the ram on a shaper was not a good candidate. Although we never discussed why? I remember Richard you mentioned something about a grinder where for some reason using a plastic wear strip wasnt desirable. Anyone care to expand or explain on these?

Charles
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
As Cash mentioned earlier Grinders, especially rotary surface grinders like a Blanchard or a Mattison as the swarf and coolant gets into the ways and acts like lapping compound. Blanchard told you to grease the ways for lubrication, but it was lube plus a seal to keep the swarf from flowing under the ways. The grease was suppose to block the water, but it ended up getting contaminated and again acted like lapping grease. So putting Turcite under there it will catch the grit or the grit impregnates into it and acts like Emery cloth. That is a place for Amco 18, cast iron or hardened steel bolt on ways.

I have put Turcite on a Elb Grinder and never heard anything. In our business "no news is good news" LOL. But those grinders are designed to keep out the coolant swarf.

I rebuilt the saddle ways and gibs of a 54" Bullard 3 or so years ago for J&S Valve down in Nowata OK. Nick Hughes the owner and he is a member here too, just can't recall his screen name. Well I was hesitant to put put Rulon on the ways, but he insisted so I did, plus put on new way wipers and a automatic lube. I chatted with him a few months ago and he said so far so good. I was afraid of the squish factor. Nick is also a student and a damn good scraper, machinist, a nationally know Gun-Smith, is a good Millwright and supervises his men who travel to power plants and oil rigs where he replaces and rebuilds gate valves. Rich

Pic's: 1 2, 3. Cody of Moglice sent me these pictures of a Mattison Rotary Grinder he Mogliced. Pic 4 is a picture of what happens when you forget to roughen the bond surface of VMC. A local company sent this to me a couple days ago, told me a local rebuilder did the job, and wanted my opinion.
 

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Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
I have to say first off I used to be a MOGLICE rep and know Drew Devitt as a friend. I have used Moglice is several places. It has revolutionized the rebuilding and building industry in several area's. Abbott Machinery down in Alton IL <http://www.abbottmachineco.com/index.php/recent-projects.html> uses it on there G & L and all types of BIG machinery including Roll Grinders, lathes, etc.. I have used it on small machines mostly in the bores of EE Tail-stocks, on Hardinge saddles, on feed screws, 1/2 nuts, on Bullard under table ways. I had problems with it at first because if you do not set it up right and pour it when the alignment is off you can't scrape it as it will dull carbide scraper blades fast, so you have to chip it off and start all over again. It is expensive to have to have a do-over. I was in Taiwan when the Moglice President first introduced it to Taiwanese builders 30 years ago. We demo'd using Moglice at Kent Machine. They liked it but as most builders don't use it because it is so hard to apply in a production setting. More skill is needed then gluing on Turcite and Turcite /Rulon is more forgiving as it can be scraped.

Studer in Switzerland used to use Moglice and now use their own mixture that resembles Moglice on their super precision grinders. They have massive fixtures that they set on top of their epoxy granite bases. if they are using it, it has to be good right? Here is a cool movie...Machine overhaul - Studer

There was a copy cat product that Philadelphia Resins made (Now ITW) years ago that had some issues, I do not know if they still make it as I haven't read about it in years.

Like all products there is a few failures and I have pulled apart a few machines and have seen grit embedded in it, but I have seen grit embedded in Turcite too. If some of your recall last fall I helped Precision Machine in Milwaukee who installed Turcite wrong too. It happens. If you go to the moglice.com website you can see several jobs they have done and never had issues. VetteBob recently showed how he Mogliced his EE saddle in the Monarch forum.

Look closely at picture 2 and you can see the dot design that Studer uses the 'Dots" that are high spots so they don't have to scrape it. Their molding fixture has dots spot faced in to it. This machine was worn on the right rear vee way, so we sent he base out and had the Studer Moglice ground down to the low worn area on a huge way grinder at Daniluk Machine Rebuilding in Oklahoma City ,http://www.daniluk.com/grinding-services.html, then it was 1/2 mooned with a Biax flaker. I had to scrape the table top as when they ground the table, the top was not parallel to the wheel head slide ways, by about .002" I scraped it so the inside of table top was .0001" high so as it wore it got better. Rich
 

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Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
One new Idea I have been teaching is something I saw on a Fadal VMC and it is so simple. Next time you put on way wipers, put a wedge behind them so when the slide moves forward the wiper pushes the dirt off to the side, as one of my students said...like a snow plow pushes snow to the side. The old way of pushing it straight ahead let chips and dirt stay on the ways. Rich
 

Mcgyver

Diamond
Joined
Aug 5, 2005
Location
Toronto
so sound like there is nothing wrong with it, it just requires the correct application.

For an up and coming 10ee project, I've being seesawing between moglice and turcite. CI/CI is a distant third as I like the idea of moving lead screws etc. Seems to me the effort the get the saddle aligned for a pour would be less than the effort to scrape in turcite'd saddle.....but i go back and forth of the subject

the other post suggested to that that moglice was a failure, which I taking from your post Richard is not the case.

you mention a number of other applications, half nuts, tailstock bores - how thick does the material have to be for a proper application? I'd assumed i'd have to mill some off the bottom the saddle before using moglice
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
Moglice used to say .062" depth, but recently I have heard them say .040" Best to call Cody the Moglice Tech that does installations plus is the new sales manager after Bruce retired. I'm sure not everyone likes it as it is dirty and when your cleaning off the extra that has spill over. Using a cut off wheel on an air grinder spreads dust all over. You have to wear a dust mask or a respirator. There is good places for both products and Phenolic. Cash may have had a problem with it, It happens as does the Turcite as I showed. I have had Moglice score filler products fail and it was a costly problem. I believe they now have fixed that issue too. I was filling a score in a Radial Arm Drill Column up in North Dakota in the summer and it was in a un-air conditioned shop and the humidity was high. The plastic metal epoxy would not dry and after 2 tries I ended up using Devcon Plastic Aluminum and it worked. Rich
 

Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
Many wonder why do we use a wearstrip in the first place and just put it back together after it is machined and scraped. It's important to bring it back to the original height so shafts line up, racks and pinions engage properly, clearance surfaces don't rub, regain center original center height, gibs fit right and don't fall in. A lot to remember, but it's all common sense and if your mechanically inclined and patient you can rebuild your machinery. That is whats so good about this forum, we have experienced advisers who can help you. Rich
 








 
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