Modifying a Grizzly 9 X 19 (G4000)

[sbwhart]

Hi Bernd

That Turcite stuff sounds like the dogs b*****ks, an interesting project to do will be watching with great interest.

Have fun

Stew

[bogstandard]

I shouldn't think you would have any trouble getting the carriage to sit level.

Get the main bed level, stick your super-duper material onto the v-way. Put carriage onto prism slides and using feelers on the uncoated side to get the carriage level. Make your turkey stuff the same thickness as the feeler pack minus say 0.002" to allow for epoxy thickness. That should get you very close, then if it does need slight adjustment, onto the surface grinder for a tiny skim and true up until the carriage sits perfectly level.


John

 

[Bernd]

John,

Sounds good. I need to get some epoxy now and on with the project. Will report when I've got it done then.

Bernd

[Bernd]

Have done a bit more on the Grizzly carriage. After I ground the cross slide table parallel I mounted it on the Bridgeport table and slid the carriage on to it upside down. I aligned the whole works with a square. Next I took a piece of 1/2" square stock and used a short piece as an alignment tool. I clamped the tool down with some parallel clamps I had made.



I then checked for "zero" at both ends.





And once in the middle just to make sure there was no bowing.



I then took the alignment tool and milled one corner off. This would provide a flat to take measurements off of so I could get the proper depth. I could have used a piece of hex stock, but don't have any in stock.



First to get milled down was the large flat. As you can see it didn't come very level from the factory. That's just a light cut to see how much needed to be milled off. I eventually took off .06" (1.5mm). About the thickness of the Turcite on both the flat and V groove.





Next was the V groove. It entailed cutting one side at a time. I kept working the depth (Z axis) and Y axis to clean up the V groove. I kept measuring until I had taken the V groove close to .06" (1.5mm) deeper.



This is what the Turcite looks like that I have. The greenish side is the side that contacts the sliding surface. The brownish side is the side that gets glued to the machine part.



The material is easily cut with a sharp utility knife.



It's also very flexible and can be bent in a circle.



Next job will be gluing strips on to the carriage using epoxy. Your just going to have to wait till I purchase some glue before I can go on with the thread.

So until next time.

Bernd

[Darren]

Looks like you have been busy Bernd 

A very interesting thread, please keep it coming. It's great to see how you are tackling this project 

[Gerhard Olivier]

This turcite looks like a very nice material.  How much presure will it be able to take???

Gerhard

[Bernd]

Thanks Darren.

I have a feeling this is going to be one long thread before I get this lathe to were I've be thinking it should be. I just hope I don't get it to messed up.

I temporaily put a couple of the turcite strips for under the carriage. Already it slides much smoother than it did on metal to metal contact.

Next on the to do list is glue the strips on, scrape for a nice bearing surface, and make the gibs.

Bernd

[Bernd]

Wow, I can’t believe it’s been almost 3 months since I last posted on this project. I have worked on it off and on, more off than on.

First to answer Gerhard’s question. I don’t know how much pressure it will take. I do know that some of the castings that this material was applied to weighed up to 2 tons or more. So I would say it can withstand a high pressure. More than what I believe we would use it for.

Now on to the gluing and scrapping to get the slide in its proper position.

Here are the materials that I used, a 60 minute epoxy, acetone for a cleaner, piece of card stock to mix the epoxy, the piece of turkite and some weights.


Mixing the epoxy.


The large flat area gets the first piece glued to it.


Then one side of the “V” grove. Notice the squeezed out epoxy. This will get trimmed with a scrapper.


Once both sides a glued in and a couple of days to fully dry, the ends are trimmed to length.


A quick pic of how the “V” grove pieces were held in place.


And there we have it, the three pieces glued in.


Once I determined how bad things were out of alignment it was time to start scrapping the turkite. As you can see that’s .079” off just from the left of the indicator to were it is set now. Lots of scrapping to do.


And here’s why. The one “V” groove. I setup the Bridgeport again and used the 90 mill to bring it back into proper alignment. After I did that there wasn’t much left to get it close.


After a bit of scrapping I set the indicator to “0” on one side of the surface and then checked the other.


And here’s the other side.


So that’s where this project stands at the moment. Next will be to figure out the making of the way gibs. Going to have to go back and read how it was do on Darrens lathe before I can go any further.

Until next time.
Bernd

[Rob.Wilson]

Hi Bernd

Great thread , i love this sort of stuff , nothing better than a bit of machine surgery    keep it coming

Cheers Rob

[Bernd]

Thanks Rob.

The scrapping job was the hardest to get done. A real pain in the butt. It's not 100% but will have to do. Now I can get on with the more interesting stuff.

Don't hold your breath though, you'll pass out. I may but this away again and not touch it for some time. 

Bernd

[madjackghengis]

Hello Bernd,  Having never bought a new machine, I have had to rebuild every lathe and mill I've ever owned, and found they are far easier than they appear.  As far as your underside, with only one and a half thousandths difference, I'd use a scraper and straight edge to level it and get it flat.  I'd use the same method to increase the contact area of your v ways on the carriage, using prussian blue and bluing the way, sliding the carriage to see the contact patch, and scraping off the blue, doing the flat way alternately, to keep the carriage parallel as much as possible.  E.F. Connolly's "Machine Tool Reconditioning" is where I got my info, borrowing the book from an interlibrary loan, and using it to rebuild a machine built in the 1870s.
     I've rebuilt two logan lathes the same way, making my own straight edges out of cast iron scrap, cut, ground, filed flat, and then scraped to match a surface plate using the prussian blue until I had about an 85% match up.  If you don't have a proper scraper, you can take a piece of flat stock, say an eighth by one, braze a small bit of carbide to the end of it, say an eighth by quarter by one inch, with the quarter in side down flat, and then grinding the end square off centered on a green wheel, giving the end of the scraper a very slight radius side to side, so it "bites" in the middle, and sharpening it by lapping it on a diamond "stone" holding the stock vertical, getting a square end, and drawing it edge-wise toward you to get the very slight radius you want.  After scraping away high spots, lay the scraper flat and scrape off any burr, and then rub in the blue again, just scraping off the bluing.  You can get a tube of prussian blue at any art store or the like, and a tube will last decades, mine is almost thirty years old and only half gone.  If I can give any help on this subject, it is my expertise, as I've rebuilt many machine tools instead of running them, when I was a machinist, and use the same methods to fit general machinery together.  Mad Jack

[Andrew_D]

I've been following this thread as well as reading the threads on fixing Darren's 7x and David's 7x. My plan was to start working on my 7x12, but I haven't got that far yet. Keep coming with the updates. Hopefully I'll finally get through the list of projects soon and start on mine. I'll need all the inspiration and tips I can find...

Andrew

[Bernd]

Mad Jack,

I used to work on the assembly floor of a shop that builds gear cutting machines. There was always alot of scrapping going on to final fit some of the parts. Am quite familar with the Prussian blue and other compounds for marking.

I don't know if I'll go any further on the lathe from were it is now. I think it will be good enough. Going to go back and check it again just to see how far off it is though.

Progress will be slow, as this project is not a priority. Would like to get the saddle done though.

Bernd

[Bernd]

Andrew,

As I told Mad Jack, this is not a priority project so will be slow going.

I'll be sure to post as I do some work on it though.

Bernd

[madjackghengis]

Mad Jack,

I used to work on the assembly floor of a shop that builds gear cutting machines. There was always alot of scrapping going on to final fit some of the parts. Am quite familar with the Prussian blue and other compounds for marking.

I don't know if I'll go any further on the lathe from were it is now. I think it will be good enough. Going to go back and check it again just to see how far off it is though.

Progress will be slow, as this project is not a priority. Would like to get the saddle done though.

Bernd

Hi Bernd, I'm glad you've got the scrapping background, I didn't want to jump in and lay it all out, but wanted to make sure you knew what to do, and you obviously have had the experience.  Scraping seems to be a disappearing art, and it sorts out old machines too well to be lost.  By the way, what kind of Logan are you working with?  I've got a 1948 820, ten inch, which is showing its age right in front of the chuck now.  I bought a couple of different cross slide castings from MLA, when I didn't have a mill, and the atlas type with a hole for the top slide, and slots in the back for rear tools has been on it since I finished machining it, much improvement over the original cross slide and top slide arrangement.  Looking forward to seeing the finished project.  Mad Jack