Modifying a Grizzly 9 X 19 (G4000)

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Bernd:
After much contemplation and checking with an indicator I've decided that the best thing to do is to machine the surfaces of the carriage that ride on the bed ways.

First I needed to find a nice flat surface on the carriage to mount on the mill table. My first thought was to use my two 1-2-3 blocks. This turned out to be a not very ridged set up. The surfaces that need machining were unsupported. So I thought why not use the cross slide table since the Grizzly's table is nice and flat. I had thought it would be flat, NOT. When I placed the cross slide with the face that is used to mount the compound slide on the surface plate it rocked. Now what? I turned it over and tried the surface that actually rides on the carriage. No rocking. So of I went to the surface grinder to remove that rocking. The first pic shows were the wheel started just skimming the surface. Lower left. The darker part of the pic.

After removing just .002" (.05 mm) this is what the surface started to look like. Not very flat.

It took another .004" (.1 mm) or a total of .006" (.15 mm) to clean up the whole surface. BTW that is the top were the compound slide bolts to. I then flipped the cross slide over and clean up the other side. Now the cross slide table would at least be flat and parallel. A quick check with an indicator on the surface plate that to be true.

Nice I placed the carriage on the cross slide table and started to check the contact surfaces of the flat carriage way. Note that the indicator is set at "0".

Next I moved it across the way. It shows a drop of -0.010" (.25 mm) in that small area.

Next I moved it all the way to the end of the flat way and got a reading 0f 0.008" (.2 mm) A difference of 0.018" (.46 mm) from the second reading.

Next I wondered if the V way was actually a 90 degree. I checked that with a small Vee Block I have. The bed V checked out not to bad.

The machined V in the carriage was another matter.

Stay tuned as I figure out how I'm going to machine these surfaces. A bit more thinking and studying the problem is needed first.

Bernd

bogstandard:
Bernd,

It is a shame you don't live a little closer, as I have a large 90 deg milling cutter that would have done that easily. You could use a 90 deg countersink but I don't think it would leave a good surface finish.
Or mount the whole job at 45 degs and use a standard end mill.

The way to get a superb finish is to use your surface grinder. Mount the part up at 45 degs, gently scoop a bit out of your wheel sidewall to a width just slightly wider than the depth of the face you will be cutting.

See attached C-o-C

Bogs

sbwhart:
Bernd

If you set it up in a horizontal mill, as for John's grinding set up you could then run a side and face mill down it.

Hope this helps

Stew

bogstandard:
Just getting back to your problems Bernd.

These are the sorts of issues I was finding when I tackled Darrens lathe, so expect to find a few more little surprises yet.

It will be a matter of getting one bit done, then finding something else. You will have to call it a day at some point, otherwise you are going to end up with a lathe that will be too good for the work you have in mind for it.

Then you will have to find another to modify, and you will find something wrong with that one, and it goes on and on and on.....................................................

John

Bernd:
Bog's

I wish I lived closer to you too. I sure think I would learn a few more things from you. Unfortunately they put a lot of water and distance between us. I have also given much thought to all the suggestion you have given here.

Yes a 90 degree milling cutter would be the thing to use on that V. If I only had a horizontal mill or a 90 degree attachment. But a visit to your shop to have you run it through your machine would surely be enjoyable visit.

I do wish I could set up the grinder to grind that out. I just don't have the tooling to do that right at the moment unfortunately. And what your saying about were am I going to stop with mods is kind of like doing a bathroom remodel. Before you know it you've got the whole house torn apart. Ask me how I know that.

You have to remember I've had this lathe for close to 10 years and Grizzly's quality control wasn't that great back then. It's a wonder it even cut stock off a part. I know it won't cut threads worth a darn.

Here's what I plan on doing. I'm going to mount it on the Bridgey table. Indicate it in. Then I'm going to mill the two surfaces. The flat with an end mill to get that warp out of it. I'm going to try with an end mill with a 90 degree end on it to clean up the V grove very very carefuly.

Then I'm going to try something that I've never seen mentioned on any of the metal working forums. This is a process that used to be done at the place I worked. I'm going to "try" and glue "turcite" on the machined surfaces. This was a material that was glued on the ways of the equipment we built. I'll take some pics of it later and post it. Very interesting material. First I need to contact an old friend at work and see if I can find out what kind of adhesive was used to attach the material.

My biggest fear about doing this is to get the cariage to sit level once I'm done with the machining. Believe me I'm not going to look any further for problems on the cross slide once this part is done. I look at it this way. I don't think I'll be off any worse than when I started.

This will take some time and careful maching. More later.

Guess I won't need to contact my friend after all. Just did a google and look what showed up. Turcite - B Slydway and what adhesive is used.

So I guess it's onward with the project. I'll keep posting updates as they become available.

Bernd

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