Kitamura Mycenter Head Way Turcite Repair

[Richard King]

For the last few days I have been rebuilding or repairing the Z headstock ways on a Kitamura Mycenter VMC. The owner operator Jay Simon of J.V. Machine Company - Part Production | Elko, MN a 2 man shop called me and asked if I was still rebuilding as I re-Ruloned another of his Kitamura's about 5 years ago. Now that I am about ready to retire I don't do the conventional rebuild most companies do. I had him dismantle the machine, clean it, remove the old worn Rulon (same as Turcite) and I went over Monday and Tuesday we put on new Rulon as the Z ways were worn .017" low on the bottom.

I goofed up taking the pictures of how I roughened the ways before I glued it (had it on movie mode on Camera, and I need to figure how to cut out a single frame, My son will know how) But I did take pictures of how I had the customer make dummy ways...same size as Z ways that were ground. I used wax paper as a release agent..and put the new Rulon 142 on all at the same time. Now I am scraping the head and hope to finish today or Monday. Here are some pictures. Rich

 

[Richard King]

More pictures

It had .032" thickness Rulon on it so we put that back on. Kitty did a pretty good way. They milled pockets .015 deep fr the Ruln to seat in. I am not super excited with the 4 pad vs. complete length. But it ran that way for 15 years. See the dummy ground bars I used to epoxy the new Rulon on when it is on the floor. See the Gib as I left it out about .125" so I have a few scraped on the machine to fit, Also how I used a utility knife to cut off the extra after it dried, Used a file, scraper and knife on hold downs and gibs, square cut scraped the Rulon before bluing it up first with a straight-edge on the ground (what I call prequalifing it) now it's on the blued ways on the machine. I'll add some more pictures of that. My customer called and he is ready for me to drive over. Have a super day! Rich

 

[MCritchley]

Thanks for sharing Rich!
That's a cool setup.
As always I have a few questions:

Did you make the bars thinner than the way to compensate for the material you will scrape off?

How much clearance do you typically leave between the keeper and rear of the way?

 

[Tyrone Shoelaces]

I used to use newspaper to prevent accidental unwanted adhesion. Not a very good method to be honest. You were left with bits of glued on newspaper to scrape off. Then they brought out the aerosol release agent. I was a bit nervous the first time I used it but no problem. It works a treat.

Regards Tyrone.

 

[Richard King]

Hey Matt :-)

I had them first mill the bars so we had to flat surfaces before sending them to the grinder. When they came in from the steel supply and after Jay the owner cut them 1/2 longer then the head ways we checked them on a surface plate and they were bowed .011. We had them grind them to the exact size as I figured the glue would not squeeze all the way out and sure enough even with all the clamps the glue that had .003 glass beads in it and sure enough it was about .006" higher on the first time up there.

Last night Jay needed to add .008" shims under the read hold downs so the head would slide up. He put it up there after I left last night. Then today when I got back he had the head on the machine and indicators on the test bar as shown. when we jacked it up the front indicator was dead nut's zero and the side indicator showed .001" with the bottom of the bar looking from the front of the machine + at the bottom.

I then had him go up and feeler gage the head fit to the Z ways and discovered there was a gap at the top. I said tight the top jib and he said it was as tight as he could get it and then said it's tight on the spacer on the gib screw. I said take the spacer out and tighten the gib and he did and the side then checked .0001". We checked it again and got the same. .0001" side and zero front. I told Jay I generally leave the front test + at the bottom as the dirt goes in there first and it wears better. He said to leave it zero. I also told him we needed to put the jack on the back of the table closer to the ball screw and we moved it back on the table and got the same reading.

Then we took it off the machine and I step scraped the flats .006" and checked the ways so they were parallel to where the ball screw mount surface was and is. It was because the glue didn't squeeze out evenly. After I step scraped it and put the dummy bars back in and then used a surface gage on the bar and checking where the hold down bolted too. It was about .001" the right way, meaning the hold down is tight .001 when we start.

I explained Rulon "wears in" after a few months so I figure it will be tight .0005".

I also showed Jay how to cut the oil grooves into the Rulon, note how I had him use a Zig Zag pattern.

I left there today and will be charging him 17 hours plus 2 1/2 driving time. Just the way I like it as dismantling, cleaning and assembling is young guys like Jay and you Matt. :-)

 

[Richard King]

More pictures....I finished up my job, Now Jay has to clean and replace the lube fittings, cut the oil groves in all the new Rulon, He did them by hand with te sharpened 3/8" dia steel bar end and re-assemble it.

 

[ironsmith89]

Great post Rich, it looks like your using the round bottom flaker blades on the turcite? I've been using those myself, much easier to steer and get the proper depth when I'm push scraping the slippery stuff.
Chris German

 

[Richard King]

Yes I have been recommending using flaker blades for several years. While in Taiwan we experimented and a neg 12 rake worked the best. You would not believe this but I put a wood plane in the car today, but it was 3 blind scrapes to remove the .006'. GMTA I guess....:-) I have never used it, but thought about using it. ESP. Rich

 

[cash]

Interesting thread, thanks for posting Richard.

Can I assume before dismantling either you or the shop took all the necessary measurements so you knew the numbers you had to build the turcite back up to?

In your post where they have there test bar in the spindle you are checking square.

I assume these same checks were done before disassembly?

I would assume in the factory when building a VMC they are doing this with with the column leveled on its back so it is easier on and off with the spindle housing?

 

[Richard King]

Interesting thread, thanks for posting Richard.

Can I assume before dismantling either you or the shop took all the necessary measurements so you knew the numbers you had to build the turcite back up to?

In your post where they have there test bar in the spindle you are checking square.

I assume these same checks were done before disassembly?

I would assume in the factory when building a VMC they are doing this with with the column leveled on its back so it is easier on and off with the spindle housing?

I did another Kitty for Jay the customer 5 years ago and he helped me last time. This was a machine he bought down in Chicago. He also had Productivity a local dealer come out and help him level and align it plus fire it up as he said he isn't a electrical expert...lol..neither am I....lol.. After they leveled it with 2 levels and got it running they swept the table top. He said it was .017 in about 12".

Then he pulled the covers and wipers and started to feeler gage everything. He said he could slide in (I think he said) .010 in he top flats. The top was not worn, it was worn at the bottom and top rear hold-downs. He then called me and asked if i was still rebuilding or retired. I said I would do the scraping (like last time)and he he would have to take it apart, clean, order the material, new lube fittings, rigging, etc. He took some pictures too. I need to remind him to email them to me. I saw them yesterday and they are a mess.

Kitty and many builders screwed up when they built the older machine 80's and 90's. when they cut the oil groves into the the Turcite, they cut through it and this allowed coolant to work under the material and rot the glue. So after Jay and I talked he pulled it apart. He didn't need to check it other then the table sweep and feeler gage. The head hold downs don't have a gib for take up. Like i said Jay is sharp and has 4 or 5 of these Kitamura's so he knows. He is not only a good machinist he is a good mechanic. He is the man driving the forklift plus he did all the crawling on the machine when I took the pic's.

As I teach on machines, the factory milled the adjacent area's next to the ways were factory milled at the same time the ways or Turcite area or same set up so you use those surfaces to measure from. Not rocket science in any fashion. As I said I used the area where they bolt on the ball screw bracket and the area where the hold-downs on referencing unworn clearance areas as a guide.

Jay ripped off the old Turcite and cleaned it. i also had him use a meps torch to sweat oil in the cast iron, he also had a wire brush on a angle grinder to clean the ways that were roughened from the factory. My first day was Monday and I used my BIAX scraper and took a clean up cut on the area where the old Turcite was to open the pours where the old epoxy was impregnated that didn't come out of the factory roughness. Then turned the blade sideways and scratched the heck out of it. cleaned it again, sprayed with super fast dry contact cleaner and gluded on the new material. Jay measured the Turcite when he took off the old stuff, there is always areas that don't wear that are original plus he had some Rulon from the last job and it was .032 too.

 

[Tyrone Shoelaces]

Interesting thread, thanks for posting Richard.

Can I assume before dismantling either you or the shop took all the necessary measurements so you knew the numbers you had to build the turcite back up to?

In your post where they have there test bar in the spindle you are checking square.

I assume these same checks were done before disassembly?

I would assume in the factory when building a VMC they are doing this with with the column leveled on its back so it is easier on and off with the spindle housing?

That's good point Cash. I've known inexperienced guys just tear a machine down before doing the tests and taking the measurements. Then they end up taking parts on and off several times before they get things right. You need to know exactly how far out the part you're repairing is before you start to do the repair.

Regards Tyrone.

 

[Richard King]

I have received machines that were not running or were in baskets, or when we built new machines in Taiwan and Turkey. Starting from scratch is easy if you follow the design signs of the new machine builder on a worn machine or follow the same principals of machine design. I don't disagree with the idea of making tests prior. Cash you rebuild surface grinders that you know grinds bad, do you grind the 5 blocks before taking it apart to see how bad the machine is? I doubt it because you know it's bad. A waste of time, right? People take my class because they know their machines are bad and want to know how to fix it. I teach new students to play detective on their machine and measure things before hand so they need to decide what to do, either scraper mill it.

On this machine it was obvious the Turcite was bad and no need to make measurements prior. But I am experienced with these machines and have repaired and rebuilt these simple box way machines. Jay had seen it before too, so he knew it could not be adjusted, it needed new Turcite. Like I said this is a common problem seen on many machining centers that use Turcite.

I hope I don't come off sounding like I'm bragging, but I can't remember how many machines with Turcite I have repaired and rebuilt. How many new machine builders I have taught the same principles to follow. If I wanted to think of why I tell "all" how to fix them for free. My calling I guess.

Like I said in the first few posts, that was the first test we made after I put the new Rulon on using the ground dummies that were duplicates of the ways on the column. After I followed the factory un-worn surfaces, used the as my guide checked the new installed Rulon to be sure it was flat (prequalify) we blued the column ways, put the head up there (he did after I left for the day) put in the gibs that I had prequalfied and knew they were not high in the middle, scraped the hold downs and relieved the middle.

Like I said I do not like the way the machine was designed with the 4 pads, but it ran that way for years that way and gradually wore out. But after I used my straight edge to make sure the ways were flat we put it together Ran it up and down one time and it was good. That's a little luck, but mostly experience. Rich

 

[cash]

OK-it just clicked-so you went off the back strap surfaces to take your measurements. As you say when the machine was made-and hopefully they machines/bored everything square these should be perpendicular to the spindle. Makes sense.

the ex K&T guy who works with me would make it a point back in the day to talk to the manufacturers to learn what they used as reference points when building the machines.

Then when we would be rescraping he would know what was a good surface to locate off of.

when we will go to repair /scrape a machine we will take some measurements first. We like to at least have a starting point and then back track as to what is good/bad.

But for what you have here in this Kitamura it sounds pretty straight forward.

I am going to go back to working on my "dive-bombing"

 

[Richard King]

When I used to rebuild big G&L Boring machines, Bullards and needed the rails or saddles milled. I would go a step past what the machine builder did. I would have them machine pads like your friend told you about on the outside of the straight and square new machined surface on the opposite side of the way, parallel to the machined way for testing only. So I didn't need to put a big blade square or granite square to check squareness of the travel. Made my job a lot easier when we had it back in the shop scraping it.

When I send a swivel plate off a cylindrical grinder out to have it ground I scrape one side flat so when they set the plate on the grinder it is flat and they don't have to shim it or set it on jacks. I have found from experience don't send a warped plate to a grinder or 9 out of 10 times it will be warped when it comes back, ground and looks beautiful but warped. Remember the 4 rules of scraping Cash while scraping Hunters Christmas present. That.s a wonderful thing your doing there friend. Merry Christmas. Rich

 

[DavidScott]

Thank you so much for this thread!!! I have a 2001 1Xi, the 30 taper mill, and was wondering if there is a way to tighten the head clamp downs since they didn't put gibs there?

 

[cash]

When I used to rebuild big G&L Boring machines, Bullards and needed the rails or saddles milled. I would go a step past what the machine builder did. I would have them machine pads like your friend told you about on the outside of the straight and square new machined surface on the opposite side of the way, parallel to the machined way for testing only. So I didn't need to put a big blade square or granite square to check squareness of the travel. Made my job a lot easier when we had it back in the shop scraping it.

When I send a swivel plate off a cylindrical grinder out to have it ground I scrape one side flat so when they set the plate on the grinder it is flat and they don't have to shim it or set it on jacks. I have found from experience don't send a warped plate to a grinder or 9 out of 10 times it will be warped when it comes back, ground and looks beautiful but warped. Remember the 4 rules of scraping Cash while scraping Hunters Christmas present. That.s a wonderful thing your doing there friend. Merry Christmas. Rich

Damn! Now you have me thinking on the 4 rules, I know the 4 rules of gun safety by heart.

Over coffee tomorrow morning I will review on your DVD.

When I was watching it I was sorting out the technique and scraper blades.

 

[Richard King]

David when you sweep the table is it + on the operator side? The head is tipped? If you pull off the wipers on top and bottom can you slide in any feeler gages? I suspect not only the hold down is worn but so is the bottom. You could measure the gap and then for an experiment loosen the hold downs, cut some brass shim stock 1" wide x 12" long .002"more then that gap, bend a so there is a 90 degree bend in it so in case you accidentally drop it. Tighten the hold down, then check the top flat and see if it pulled the top flat against the ways. Then go to the bottom and see if you can slide in the gage and sweep the table again. See what happens then. Then we can decide on the cure. Rich

 

[Richard King]

The 4 Rules of Scraping by Richard King:
1. Move the blade sideways so you get individual scrape marks. The low scrape mark width and the opening no or high spot scrape mark is the same size. O O O. If you move to slow the marks will overlap OOOOOO and you will get long openings or groves when you blue up. Short Version 1. Individual Scrape marks

2. When you scrape the next line of Individual scrape marks make the to the top of te new line and old line there is an opening or no scrape marks
OOOO
open
OOOO Or when you blue up you will have long vertical grooves on no blue. Short version 2. Individual Lines

3. Depth meaning press the springy blade down so you scrape a minimum of .0002" to .0005" deep. Use a surface gage to measure how deep you scrape. Always push down the same pressure weather your roughing or finishing so the dept stays the same. Short Version 3. Depth of scrape mark.

4. Hinge the part. This means check the Airy points, Rotation of points so you know the part is flat. I like to see it pivot or hinge 30% from both sides. Short version is the same.

Ask Matt 1, 2 or 3 to come over and they can show you. :-) Rich

 

[Milland]

Thank you so much for this thread!!! I have a 2001 1Xi, the 30 taper mill, and was wondering if there is a way to tighten the head clamp downs since they didn't put gibs there?

Rich will have a better answer, but I suspect if you've got that much play you'll want to do just what's seen in this thread. If the Turcite happened to be worn evenly then perhaps it would be safe to mill or grind a shallow step into the clamps to bring the bearing surfaces closer when tightened.

 

[Richard King]

yes....or put on new thicker Rulon on the hold down, but I suspect if the hold down on top is worn, the bottom flats are too. but heck lets check. :-)