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noob question - Turcite / mating cast surface

motion guru

Diamond
Joined
Dec 8, 2003
Location
Yacolt, WA
We have a machine that we are cleaning up for a customer and updating controls and functionality. As we disassembled the machine it was clear that the transfer axis had a lot of wear.

A couple of questions after cleaning things up and considering next steps.

1.) First up . . . Turcite how is it pronounced? Tur-Kite? Tur-Site? I keep hearing people pronounce it both ways . . . I don't want to perpetuate ignorance of proper word pronunciation. :nono:

2.) This set of ways is lubricated with grease. And it is a grinder that in its original configuration had all matter of swarf leaking onto the ways. Made a nice lapping compound and in my opinion is a crap design. We have solved the leaky swarf issue and cleaned up the Turcite mating surfaces to dead flat (were worn in a twist of +/- 0.005 inches). Given that the machine only trasfers from position A to position B and is never in motion when grinding. Any recommendations for a modern grease?

TurcitResurfaced.JPG

3.) The cast iron ways were also worn +/- 0.004 in same helix twist as the Turcite and have been surface (fly-cut) to flat, but not scraped. Recommendations on final surface treatment before reassembly to provide longest life?

CastTable.JPG
 
Hi MG,
I'm noober than you with use of Turcite, but for truly long life is there a chance that a recirculating oil with pump and filter would be a better "long life" method than any grease? Unless there's an automatic grease pump on the machine, I'd think that irregular relubrication with grease would not be ideal.
 
We have a machine that we are cleaning up for a customer and updating controls and functionality. As we disassembled the machine it was clear that the transfer axis had a lot of wear.

A couple of questions after cleaning things up and considering next steps.

1.) First up . . . Turcite how is it pronounced? Tur-Kite? Tur-Site? I keep hearing people pronounce it both ways . . . I don't want to perpetuate ignorance of proper word pronunciation. :nono:

2.) This set of ways is lubricated with grease. And it is a grinder that in its original configuration had all matter of swarf leaking onto the ways. Made a nice lapping compound and in my opinion is a crap design. We have solved the leaky swarf issue and cleaned up the Turcite mating surfaces to dead flat (were worn in a twist of +/- 0.005 inches). Given that the machine only trasfers from position A to position B and is never in motion when grinding. Any recommendations for a modern grease?

View attachment 221013

3.) The cast iron ways were also worn +/- 0.004 in same helix twist as the Turcite and have been surface (fly-cut) to flat, but not scraped. Recommendations on final surface treatment before reassembly to provide longest life?

View attachment 221014
With the lube channels in the cast iron ways, it looks like it should be oil lube not grease. Is there a manual that says it is grease lube?
Edgar

Sent from my SM-G935V using Tapatalk
 
We have a machine that we are cleaning up for a customer and updating controls and functionality. As we disassembled the machine it was clear that the transfer axis had a lot of wear.

A couple of questions after cleaning things up and considering next steps.

1.) First up . . . Turcite how is it pronounced? Tur-Kite? Tur-Site? I keep hearing people pronounce it both ways . . . I don't want to perpetuate ignorance of proper word pronunciation. :nono:

2.) This set of ways is lubricated with grease. And it is a grinder that in its original configuration had all matter of swarf leaking onto the ways. Made a nice lapping compound and in my opinion is a crap design. We have solved the leaky swarf issue and cleaned up the Turcite mating surfaces to dead flat (were worn in a twist of +/- 0.005 inches). Given that the machine only trasfers from position A to position B and is never in motion when grinding. Any recommendations for a modern grease?

View attachment 221013

3.) The cast iron ways were also worn +/- 0.004 in same helix twist as the Turcite and have been surface (fly-cut) to flat, but not scraped. Recommendations on final surface treatment before reassembly to provide longest life?

View attachment 221014

1) I think its pronounced Tur-kite but not 100% on that. Kinda like jib or gib, ive met folks that swear it either way :scratchchin:.

2) Another vote for oil over grease here.

3) If you are confident in the fly cut surfaces of the table to be flat and parallel (check it), you could just flake it leaving around 50% bearing. Lube grooves are present so youre good that way.
After setting the base on the floor the way it will be set in use. Id blue the table and set it on the base for a print, scrape the Turcite as required, shouldnt need much. Id then releave the center 25 - 30% of the Turcite a couple of passes so as it just barely / doesnt print.


Im thinking this is a blanchard style grinder with a rotating mag chuck that sits atop the table, parts are loaded at point A, slid under the head at point B. Im thinking the head is tramable both ways so it can be aligned to the chuck. To my mind whats mostly required of the table is to be solid at point B, checking the vertical surfaces the head assembly slides up an down on id see as being more important. So as the head remains aligned to chuck over its travel.

Is the base/column a weldment btw? Sure does look like it. Are those bearings all that keep the table?

Just my 2 cents, for what its worth... About 2 cents prolly ;)
 
Factory manual from the 80's indicates grease . . . yes it is a weldment. And, two brand new machines placed adjacent to where this came out are also grease.

Berger Gruppe: Series DRG-CNC


We intend to put an automatic lube system in place.

If you look at the table - there are also rolling elements that keep the table from being pushed off the bearings fore and aft.
 
If using grease I'd look for a low or medium viscosity synthetic with minimal (fine) fillers. My reasoning being you want something that won't age harden or clump and fill the grooves and small tubing of the distribution system. You don't need extreme pressure additives or high-temp capacity; so many automotive greases wouldn't be appropriate. And you want fillers that won't be abrasive to the Turcite.

Low viscosity seems appropriate with the large shear area you're dealing with, that's why so many of us originally thought "oil" for this application. Make sure whatever you chose won't attack the adhesive that holds the Turcite in place.

I'd talk with a couple of the major oil companies tech reps and see what they have to say, but some of the specialty manufacturers might have formulations more in line with your needs. And there's always asking the OEM builder... ;)
 
Tur-Kite.

It would appear that both parts of the assembly are approximately the same length, meaning that if turcite is used, at some point in the travel, part of the turcite surface will be exposed. That's never a good situation. Once grit gets in the turcite, it turns it into sand paper. Even if you solved the grit leaking on the slide, on a grinding machine, there's always grit everywhere. It's just how it is.

That said, standard practice for bonding turcite to a surface involves cutting grooves for the glue to bond to. Typically it's done with something like a fly cutter and a very fast feed rate. If you can't machine it, you can scratch up the surface with a Biax or hand scraper and the edge of the insert, or even a cut off wheel if you are careful. Use the proper WayLock adhesive with the glass beads for even glue thickness. Make sure you follow the clamping guidlines (10psi).

If accuracy is not critical, you could just machine the turcite flat, or it might be good enough if you sandwiched the parts together for clamping.
 
Tur-Kite.

It would appear that both parts of the assembly are approximately the same length, meaning that if turcite is used, at some point in the travel, part of the turcite surface will be exposed. That's never a good situation. Once grit gets in the turcite, it turns it into sand paper. Even if you solved the grit leaking on the slide, on a grinding machine, there's always grit everywhere. It's just how it is.

That said, standard practice for bonding turcite to a surface involves cutting grooves for the glue to bond to. Typically it's done with something like a fly cutter and a very fast feed rate. If you can't machine it, you can scratch up the surface with a Biax or hand scraper and the edge of the insert, or even a cut off wheel if you are careful. Use the proper WayLock adhesive with the glass beads for even glue thickness. Make sure you follow the clamping guidlines (10psi).

If accuracy is not critical, you could just machine the turcite flat, or it might be good enough if you sandwiched the parts together for clamping.

Good eye - all grinding occurs in the middle of the machine and when the ends of the table transfer the active chuck into position - turcite is indeed exposed. We have manufactured a new stainless tub and coolant / mist containment system that should work much better than the OEM solution.

Also, this machine has 25-ish years of service on it so the original grease system worked OK, even if it did wear a bit. The real issue is that the chucks should be square to the spindle vertical axis when in position and even the gearboxes for the chucks were shimmed on the original machine. Our goal is to get the mating surfaces in 100% contact so that the table is stationary with no rocking when grinding occurs.
 
If you want 100% contact, you should really grind one side to at least .0005/ft flatness and scrape the turcite to that surface.

On Blanchard grinders, they were all originally designed to use grease on the ways. The operator was supposed to grease the ways twice a day and the grease was supposed to flush out the grit. It's a crappy system and most machines I have seen are badly worn.

At some point they switched to using way oil, like Vactra 2, and a timed pump like a Bijur plunger pump. They used wipers on the ways to keep grit out and periodic oiling to flush out what gets in and lube the ways. This works better. They all wear eventually, but the oil and wipers work much better.
 
Oppsie, I think I've misread the original post, I thought the original Turcite was still on the base and had been made flat. Interesting that it has two tables.The idea of scraping a nano of relief in the centre is to ensure the table doesn't rock, were only talking a few tenths.

A couple of questions.
Can you tram the head in both axis?
Were the table way surfaces originally scraped?
The base has been machined and is waiting for new Turcite?
The table way surfaces have been fly cut flat?
Do you have anyone to do any scraping?
How good does the machine need to be?
 
Original Turcite is still in place - there was plenty to take off 0.010 and get it flat.
Yes - we can tram the head in both axes
Table way surfaces were originally scraped and were worn/twisted +/- 0.004" and now fly cut flat
We have a local guy who we can have do the scraping
Machine was holding 10ths prior to the control retrofit - the decision to deal with the ways was reached with the customer when they saw how much wear there was. This explained why they had to shim the chuck gearboxes to get it to perform well enough for production.

In the end we are aiming for +/- 0.0005" repeatability on ground blank thickness. We will use an acoustical sensor for touch off - all motion components fitted with linear encoders with 10um resolution which should allow us to measure better than 10x tolerance.
 
Original Turcite is still in place - there was plenty to take off 0.010 and get it flat.
Yes - we can tram the head in both axes
Table way surfaces were originally scraped and were worn/twisted +/- 0.004" and now fly cut flat
We have a local guy who we can have do the scraping
Machine was holding 10ths prior to the control retrofit - the decision to deal with the ways was reached with the customer when they saw how much wear there was. This explained why they had to shim the chuck gearboxes to get it to perform well enough for production.

In the end we are aiming for +/- 0.0005" repeatability on ground blank thickness. We will use an acoustical sensor for touch off - all motion components fitted with linear encoders with 10um resolution which should allow us to measure better than 10x tolerance.

I think id approach it table first. Have it up on 3 points, 30% or so in from the ends aiming to minimize deflection, at a height thats comfortable for your guy. Scrape the table ways flat and parallel to each other and the table top. Never used one before but a 'two foot gage' would indicate any twist present quickly an independent of level. Dirt easy to make.
When youre done there, flip the table and set it down, blue it up and take a rub on the base. Bring the Turcite in flat and put that smidge of relief in the middle (an extra pass or two), dont go too wide as you want to maintain a decent bearing when the table is at full travel. The scraping should go pretty quick cos youre nearly there already as the surfaces have already been machined, theres no need to flip the table every time you take a print, the head is tramable so you dont have to fuss too much being uber square with the column/head. One other thing to keep in mind is alignment of drive screws etc, or anything that might be affected by the material you taken from the base and table. at a guess thats somewhere between .015" - .030"

Id be confident using that general approach, would bring about a nice result for relatively little effort and time. Be interesting to hear how your guy would want to go about things. Be great if you could post up a couple of progress pics and such too, I know id be interested :)
 
Take a look at Multiluber grease. It pours and pumps like a heavy oil, then thickens up when subject to shear in the joint. It's used in machinery like farm equipment where there's a pump that feeds lines running to the zerks all over the machine. Deere dealers should have it. I installed a Deere system on a garbage truck a million years ago and loved not needing to crawl all over and under and inside it to do the greasing, and it was still working when the truck was sold.

PMB Product:

Multi-luber lubricant

[h=1]Features and benefits[/h]· Multi-luber lubricant is a fluid grease compounded with aluminum soap acting as gelling agent
· Handles like a viscous oil, but performs at bearing surface and in housing as a grade number 00 grease
· Handles like oil, but converts to grease when subjected to shearing stresses – this process is defined as rheopetic action
· Rheopetic action depends on high shear to increase consistency
· Normal handling, which may involve agitation passing through a screen, transfer pumps, and lines, will not destroy its fluidity
image001.gif
AN11100 – Multi-luber lubricant 1qt. (946mL)
image002.gif

AN100650 –Multi-luber lubricant 1 gal. (3.78L)
· High shear (obtained by passing lubricant through valves and ports or between moving parts with close clearances) changes lubricant from a fluid to a soft grease
· Meets J15 service ratings

[h=1]Applications[/h]· Ideal for conditions in which a fluid grease for handling and dispensing is important, yet a heavier consistency is required for better retention at the point of use.
· For use in centralized lubricators on farm equipment, trucks, and construction machines in which the lubricant must flow to the pump.
· Useful in systems in which heavier greases do not flow easily.
· Sometimes used in place of oil to reduce leakage.
· Can also be used in hand-operated grease guns.

[h=1]Order information[/h]
Part
number

Description

Size
Pkg.
qty.
U.S. and Canada
AN100650
Multi-Luber lubricant
1 gal. (3.78L)
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AN11100
Multi-Luber lubricant
1 quart (946mL)
12
 
Motion and I have talked about this before via phone. In the old days mfg'ers used grease as a seal to keep swarf out of the ways. They expected the user to pump in fresh grease dailey to purge the grease. That is a real poor design of a machine. Motion has a big planner mill he can use to machine or fly cut what he has now.

If I were you I would put the machine and table on the Airy points and 3 points and re measure the machine.

I see the table is sitting on a 6 x 6 under the back side. Probably twisted as they machine is built like a noodle. Look up Kinematic mount principal or 3 points as I have discussed it on here a number of times. Many times I will add extra leveling wedges under a banana machine to help from keeping it from twisting.

Motion I thought you told me you had to use grease as the machine does not provide oil troufs to catch way oil draining from the ways? The machine was built to use grease. If the machine has lasted for 20 years using grease then use it again. If you do I suggested he install way wipers set at 20 to 40 deg's like a snow plow to push the grease and crud off the way and not like straight wipers just push the the swarp and grease forward the way and it never falls to the side. I am still available to come and consult :-) plus teach your guys how to scrape iron and turcite Kite is how I say it. Also I prefer using Rulon 142 which is the same as Turcite B.

I would also tap on the Turcite with a hard plastic hammer lightly all along the material as after years the epoxy can deteriorate and get loose. If you tap on loose Turkite it will have a slapping sound. If it is still attached the sound will be more of a solid thud. Rich

PS TStar.com or Tri Star plastics has been applying Turkite and Rulon for yours and they now have a new material that is harder and Red..
 
Hi Richard,

We mounted the table and bed on the planer mill when we measured and fly cut the surfaces. The photo of the table was after cleaning and before machining, the bed photo is after cleaning, machining and painting. You are correct in that the parts are pretty flexible.

Turcite is well bonded along both strips.

We have planned a lube pump operated by the machine controller . . . and using grease would certainly be easier than designing some kind of drip tray system. I am going to try to get Hunter engaged, and if not him, then another fellow from a local shop we have worked with.
 
Original Turcite is still in place - there was plenty to take off 0.010 and get it flat.
Yes - we can tram the head in both axes
Table way surfaces were originally scraped and were worn/twisted +/- 0.004" and now fly cut flat
We have a local guy who we can have do the scraping
Machine was holding 10ths prior to the control retrofit - the decision to deal with the ways was reached with the customer when they saw how much wear there was. This explained why they had to shim the chuck gearboxes to get it to perform well enough for production.

In the end we are aiming for +/- 0.0005" repeatability on ground blank thickness. We will use an acoustical sensor for touch off - all motion components fitted with linear encoders with 10um resolution which should allow us to measure better than 10x tolerance.

One thing that concerns me a little bit with the original approach on using grease as a way lubricant is that the effective head tram will change when grease is added and then slowly change as the grease layer dissipates.

The total mass of the saddle, chuck and part might be such that this is a non-issue but I think that the +-.0005 will be hard to hold over an extended period, i.e. from one grease shot to the next due to viscosity unless you are stingy on the grease.

I'm really partial to the Bijur systems with Vactra #2.
 
Take a look at Multiluber grease. It pours and pumps like a heavy oil, then thickens up when subject to shear in the joint. It's used in machinery like farm equipment where there's a pump that feeds lines running to the zerks all over the machine. Deere dealers should have it. I installed a Deere system on a garbage truck a million years ago and loved not needing to crawl all over and under and inside it to do the greasing, and it was still working when the truck was sold.

PMB Product:
Blue bird school busses and motor homes have a similar system.

It seems one could add an automatic pump that would add a squirt every cycle to keep both fresh greas ed in place but swarf out.

Robust wipers to keep ways clean, fresh and constant grease supply would seem to keep surface "wet" lowing wipers to work better in removing a film instead of chunks.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 
1. Any recommendations for a modern grease?

2. Recommendations on final surface treatment before reassembly to provide longest life?

View attachment 221014

1. Any polyurea thin grease will do. If moisture is not present a MoS2 addition will help A LOT.

2. Apply 5-10 micron MoS2 mixed with isopropyl alcohol. Rub hard, rubb off.

MoS2 becomes abrasive when moisture is present. Tungsten disulphide MAY not and it's a far better lubricant.Hex Boron is probably best here but I don't have enough of a track record for it.

Lower Friction
 
1. Any polyurea thin grease will do. If moisture is not present a MoS2 addition will help A LOT.

2. Apply 5-10 micron MoS2 mixed with isopropyl alcohol. Rub hard, rubb off.

MoS2 becomes abrasive when moisture is present. Tungsten disulphide MAY not and it's a far better lubricant.Hex Boron is probably best here but I don't have enough of a track record for it.

Lower Friction

Been playing a bit with WS2 and hBN and the WS2 is way more "slippery" than hBN coated surface in my experience.

btw. Thanks for the link, I have been looking for a reasonably sized packaging sizes for these. (more than 5 grams, less than 5 tons..)
 
Been playing a bit with WS2 and hBN and the WS2 is way more "slippery" than hBN coated surface in my experience.

btw. Thanks for the link, I have been looking for a reasonably sized packaging sizes for these. (more than 5 grams, less than 5 tons..)

I bought from him and was trouble free but when I use it for precision bearings ( 1/4% or so ) I buy from a reputable Chemical House. MoS2 can be contaminated with silica. Disaster. Also, unless you push it through filters don't go too fine - 5um is a good average and more is better for CI sliding bearings. OT I know, but I didn't find it helps in car engines though it worked well to prevent gudgeon pin seizure in 250cc's when I was racing ( and missing a gear... )
 








 
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