Doosan Turcite Replacement.

We haven't had a lot of meat and potatoes lately. So I thought I share a job I looked at today. I've parked my arse in a hotel, so its keeping me out of the bar that's just 7 floors below.
Last night under the cover of darkness, I flew up to Darwin, to assess this Doosan CNC mill. That's about as far as you can fly from where I am down South in Melbourne. 3,800 km's, 41 hours if you attempted to drive it.

This is really unusual. The pickles have fitted the Turcite inside out and upside down. They have put the Turcite on the upper surface of the saddle, facing the table. That would be the X axis. The Turcite is exposed and facing up.

The Y axis saddle to base is conventional. The Turcite is where you cant see it, tucked away with in the saddle.

To top it off they have milled the oil grooves clean through the Turcite. So it's all lifted. Machine is June 1999, so its lasted 18 years. They had a collection of pealed out Turcite.







Today was only an inspection. I'd need to freight up half a ton of gear to do the job. Saddle is 2,600mm long.(102"). I'd be hard pressed to find a machine big enough here, to rough mill it in. So it all has to be done by hand. 15 distinct facets of Turcite to do the X & Y axis, once you count all the gibs and retainers.

I wont quote it firm, but I figure its a 10 day job. Its going to have to wait until November, as I have a back log.

If there's any interest, I'll photoblog it.

Hot and sticky up here. We're just coming out of winter down in Melbourne, Darwin is 760 miles North of the Tropic of Capricorn. By the time I get back, it will be the wet season, where humidity goes through the roof. Today was only 35C - 95F but only 15% Humidity. They call the wet season here, the suicide season.

Regards Phil.

Do you think there is a reason why the Turcite is on the exposed slide ? Will /would you replace as is or go for the conventional approach?

Sounds like to do the job proper you need to regrind the ways and then put turcite only on the table where it belongs.

I assume the table ways got torn up so this was an "easy" fix.

I will assume there is turcite on the table as well.

sable said:

Do you think there is a reason why the Turcite is on the exposed slide ? Will /would you replace as is or go for the conventional approach?

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I've had all thoughts of grandor. Around lunchtime today, I was going to send it home, back south, rip a seat for linear rails. And remount it on linear rails.

Truck transport is 4 days minimum each way, $5 - $7k. 10 grand before you have even touched it, I figured I may as well be up here sweating it out.

Regards Phil.

That looks like a real $^&% of a job: The start of the wet season in Darwin while working in a tin shed that's sure to get to 40 deg C plus. Do you have to rectify the dodgy design decisions or duplicate the original turcite setup?. Please do blog the repair Phil.

cash said:

Sounds like to do the job proper you need to regrind the ways and then put turcite only on the table where it belongs.

I assume the table ways got torn up so this was an "easy" fix.

I will assume there is turcite on the table as well.

Click to expand...

Best I can tell, and I'm absolutely certain, the Turcite if factory original. There is no Turcite in the table. Its all on the saddle. Drawings confirms that. To make it worse when you over travel the X axis plus / minus, you can look in and see the exposed 8-10" of true table slide. The table internals are just ground. Primary flats, leading edge and gib face. Leading edge and gib face in the table are weird also. The table has been ground dead true and parallel. Both sides. It has lateral gibs, but they put the taper into the side of the saddle, rather than put the taper for the back side of the gib, in the table.

Its lasted 18 years. I don't have scope to waste 2 weeks, sending it back home for slide grinding. I figure I can do it in 10 days, from scratch, by hand.

For the first time in my life, I'm considering, I'm considering not cutting oil grooves. The way they look to the sun. I spent 15 minutes just mopping them out, before I put the tele guards back on. They just collect shit. I'm thinking about just hammering it with a deep mottle, that the wipers will still clean.

Regards. Phil.

machtool said:

This is really unusual. The pickles have fitted the Turcite inside out and upside down. They have put the Turcite on the upper surface of the saddle, facing the table. That would be the X axis. The Turcite is exposed and facing up.
..
To top it off they have milled the oil grooves clean through the Turcite. So it's all lifted. Machine is June 1999, so its lasted 18 years.

Click to expand...

First impression is the old quote:

That ain't right. It isn't even WRONG!

Click to expand...

However... lemme guess that it worked pretty well for the first ten years of those 19 years.

IF THEN.. it had been scheduled for renewal at around that ten-year mark... as a "known consumable" component?

Might the task of replacement AT ten-year intervals have been faster and easier than the "conventional" way?

More especially if "lessons learned" put more oil grooves, but NOT clear-through into the surface? On-edit.. or your other method.. no "formal" grooves atall..

Treated as replaceable wear strips, IOW.

As with tires and brakes - "economically", a more frequent, but faster and easier replacement scheme may not be as foolish an approach as first appears.

2 1/2 CW

Monarchist said:

IF THEN.. it had been scheduled for renewal at around that ten-year mark... as a "known consumable" component?

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Fucked if I know. But I'm new at this, its only been 35 years. Bill, are you just waffling? You make it sound like you just unbolt a set of Turcite and bolt a new set in. In the several thousand machine manuals I've read. I've never once seen one mention a schedule for a "known consumable" of Turcite.

Back in the 80's it was marketed as a life long product, because the COF was so much lower than cast on cast. They seamed to have missed glue bonds breaking down, and clowns cutting oil grooves right through it.

Regards Phil.

machtool said:

Fucked if I know. But I'm new at this, its only been 35 years. Bill, are you just waffling? You make it sound like you just unbolt a set of Turcite and bolt a new set in. In the several thousand machine manuals I've read. I've never once seen one mention a schedule for a "known consumable" of Turcite.

Back in the 80's it was marketed as a life long product, because the COF was so much lower than cast on cast. They seamed to have missed glue bonds breaking down, and clowns cutting oil grooves right through it.

Regards Phil.

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No. Not just "waffling". "Lifetime" has proven misunderstood marketeer hype time after time. Good for the "lifetime" of the first component to fail is the reality. Not the age of the company or the user. Lots of things were not MEANT to EVER have to be replaced. But we DO replace them.

Design service lives of new machines are not what they once were. They are meant to have earned their crust + profit, and be "used up" sooner. This looks like a valid approach for Doosan to be competitive, build-cost-wise, in that environment. Replacement was not on their dance-card. Ever. Selling a NEW machine wudda been. Second-and subsequent owner is on his own.

And yes, I know that Turcite - or any other "bonded on" material - is no picnic to remove and prep for replacement.

Even so... clearing it and replacing it from the relatively easier to fully-expose upper surface of the machine, rather than from the underside of the table seems the lesser of evils, here, time and handling-wise.

Can't avoid it, AFAICS, anyway. The bed UNDER that Turcite was probably not meant to have Turcite - or anything else - run directly against it. Probably as-cast soft.

Mind.. you/we do not yet know how much attention that table underside is going to need ANYWAY.

Better wipers, earlier replacement, that could have been near-ZERO even if not 100% perfect. Probably no longer realistic by NOW, though.

So no, I do not want to be "the guy" having to DO this task.

But if I were the budget decision-maker, I'd ask you to quote doing it the way the factory did, but use YOUR approach to something other than clear-thru oil grooves.

That could give the machine another ten to fifteen good years.

Who knows whether it even still has a job beyond the FIVE year mark, economically?
Bean-counters don't plan as far ahead as once was, either.

Scrapping, rather than scraping, remains an option.

3 1/4 CW

For the first time in my life, I'm considering, I'm considering not cutting oil grooves. The way they look to the sun. I spent 15 minutes just mopping them out, before I put the tele guards back on. They just collect shit. I'm thinking about just hammering it with a deep mottle, that the wipers will still clean.


Phil,
Have you considered cutting oil groves in the under side of the table? I would imagine you could run flexible oil lines to it. You could leave the Turcite smooth.

MCritchley said:

Have you considered cutting oil groves in the under side of the table?

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I'd bet they are already there - pressure lubed or not.

Lower-surface pattern is too broad and simple to BE much more than dirt-traps.

Psst. Don't tell my customer. They might have over taxed this machine.

I've brought the manual back to the hotel for a read.

Table load is spec'ed at 29,400N (6,600 lb). Why the spec lists a force (N) rather than a mass (Kg's), escapes me. I've spent the past hour crunching number's for the Turcite compressibility. Slides are basically 6" width by 102", dual.

This Pic if from the customers own web site. They tell me that job was 7 tonne. (Metric here). That would only be 15,430 lb. Just a touch over the 6,600 lb.

Despite that, I think the ways should have more than carried that. The mass was calculated upon what the servo's could accelerate



Regards Phil.

machtool said:

Psst. Don't tell my customer. They might have over taxed this machine.

I've brought the manual back to the hotel for a read.

Table load is spec'ed at 29,400N (6,600 lb). Why the spec lists a force (N) rather than a mass (Kg's), escapes me. I've spent the past hour crunching number's for the Turcite compressibility. Slides are basically 6" width by 102", dual.

This Pic if from the customers own web site. They tell me that job was 7 tonne. (Metric here). That would only 15,430 lb.

Regards Phil.

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LOL! Good catch!

Not a great deal short of triple the rated load, so thar' went even a 100% safety factor.. that was possibly only a 50% one, anyway...

And ... from outta the too-well-read and too highly opinionated "septic" field..



...If they plan to make a "habit" of that.. and having earned a crust at it one or more times already, they probably have BEEN doing, and why would they not continue to do?

Have a look at intentionally replaceable Bronze wear strips with graphite-ish "buttons".
Thermal coefficient of expansion is a far closer match to CI over that 102" as well.

Load vs expected traverse velocity of Oilite 16 looks better yet.

But you/they don't even want to THINK about cost of material or installation for that one!


Bigger machine should be cheaper. Maybe.

That's going to be a lot of work to jam into 10 days, are they giving you a helper or two? There doesn't appear to be any overhead lifting gear, so that's another PITA.

What a crazy way to build something.

ewlsey said:

What a crazy way to build something.

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Could say so.

OTOH, they've made a Hell of a run at doing things as they see fit:

http://www.doosanheavy.com/download/pdf/invest/audit_report/en/2016_Annual_Consolidated(en).pdf

And there you have it.

Bass-ackwards as it seems, if/as/when it fails, the evidence is right there "in your face". Not hidden.

Maybe that's a part of a "dumb like a fox" approach for machine-tools meant for sale as much into third-world markets as any other market?

Serve the better part of 19 years, fail at severe overloads? Can't be TOO bad, can it?

machtool said:

. I'd be hard pressed to find a machine big enough here, to rough mill it in. So it all has to be done by hand. 15 distinct facets of Turcite to do the X & Y axis, once you count all the gibs and retainers.

I wont quote it firm, but I figure its a 10 day job. Its going to have to wait until November, as I have a back log.

If there's any interest, I'll photoblog it.

Click to expand...

Yes please!

Would it be beneficial to pull the saddle and table and ship them back to your shop for fitting? The bottom of the saddle would have to be fitted to the base in the field, but you could tackle the X way from home.

How are you planning to clamp the turcite in place for the glue to set? Seems like they recommend 10psi, so you would need 2 X 6,000 lbs to clamp the stips on the top of the saddle.

There's a 10' slideway grinder just outside of Rockhampton, and an owner who needs more practice with it. Rocky is a lot closer than Melbourne and RC owes you a favour or 10....

You know this of course, just stirring the pot....

PDW

PDW said:

There's a 10' slideway grinder just outside of Rockhampton, and an owner who needs more practice with it. Rocky is a lot closer than Melbourne and RC owes you a favour or 10....

You know this of course, just stirring the pot....

PDW

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I'll stir this pot the other direction.

Client has drastically overloaded the machine-tool. Then bragged about it in public?

I'd not want to depend on legalese of a disclaimer WHEN, not IF, they do it again and fail the rebuild work.

I'd "no bid" this one. Who needs the risk and hassle?

Not just because I have BEEN to Darwin's climate. But that, too!

Monarchist said:

I'd "no bid" this one. Who needs the risk and hassle?

Not just because I have BEEN to Darwin's climate. But that, too!

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Darwin is OK. Between mid May and mid August. Mostly.

I spent a lot of time at sea chasing foreign fishing boats back in the early 1980's, during the Wet, based out of Darwin. No air conditioning either. Amazing what you'll do for fun when you're young & stupid. I've never been back since then and am quite happy about that.

PDW