Knee removal on VN26

[JD Bouchard]

Today I removed the knee on my VN26. It was honestly pretty easy if you have something to lift it. Four screws to remove at the base of the elevating screw, remove the gib and that’s it. You don’t need to lift it all the way, just enough to clear the powerfeed shaft and then it can be rotated out of the dovetail.

I will post more picture of the lead screw and various parts but for now I offer pictures of the rigging because I’m pretty stocked about that new-old gantry that I got two months ago and rigging pictures are cool.

But ... before I get to clean all the knee parts, I've got to deal with this black cutting oil mess situation that I have ben postponing for a year now ... This liquid is so black and nasty it's unbelievable. I guess they were using used motor oil as cutting fluid ...

 

[Tyrone Shoelaces]

I always used to remove the elevating screw first. Just in case. Screws bend very, very easily. People see the OD and thinks that’s fine but they’re only as strong as the root diameter.

Regards Tyrone

 

[m-lud]

Thats a nice size gantry to be able to maneuver around and strong enough for about anything you need to lift. That will save your back.

 

[JD Bouchard]

Ok here is a photo dump of some of the knee parts

The Gib. The SHCS cap screws hold it in place while the set screws set the depth for the adjustment

 

[JD Bouchard]

The elevating mechanism. The post has some minor scoring and the bushing is a bit loose. I will probably machine the packing gland to accept a modern seal. I’m also thinking about lightly re-surfacing the outside of the post and bore the bigger gland oversize to press in a bronze bushing. We’ll see how motivated I am when I get back to re-assembling all of this haha

 

[JD Bouchard]

Underneath the Knee. I took the oil pump out to clean it and fond out a broken spring in the plunger, so I replaced it. The flange from the power feed shaft was a lot thicker than it looks like and there is nothing to grab on. I ended up using a strong magnet to pull it out. The seal was an old leather seal and it was leaking so I replaced it, pn is SKF 17645. To be sure this area would not leak again I used a light coating of gasket maker on the steel surface. I was afraid that I would never be able to get it out again because of the RTV so I added two tapped holes on the outside surface (not pictured) to give me something to use a puller on.

 

[Tyrone Shoelaces]

The elevating mechanism. The post has some minor scoring and the bushing is a bit loose. I will probably machine the packing gland to accept a modern seal. I’m also thinking about lightly re-surfacing the outside of the post and bore the bigger gland oversize to press in a bronze bushing. We’ll see how motivated I am when I get back to re-assembling all of this hahaView attachment 428411View attachment 428410View attachment 428412View attachment 428413View attachment 428414View attachment 428415View attachment 428416View attachment 428417

I used to work at a place that made that greasy packing. It was made out of asbestos back in the day.

Regards Tyrone

 

[JD Bouchard]

I used to work at a place that made that greasy packing. It was made out of asbestos back in the day.

Regards Tyrone

I have to say that I had never seen a seal like that and I was quite surprised when I took it out.

 

[Tyrone Shoelaces]

I have to say that I had never seen a seal like that and I was quite surprised when I took it out.

You’ve never lived ! Old school gland packing, pre oil seals. Plaited asbestos thread passed through grease and then graphite powder, then a square die to form the square shape. You could always tell the guys who worked in that department - their overalls shone like leather with the graphite. The packings came in several sizes from about 3/16” square to over 2” square.

You usually put more than one strand in, more like 5 or 6. I had a little jig that cut them all to the same length and “ scarfed “ the joint at the same time. You’d put one strand in with the joint at 12, the next at 3, the next at 6 etc etc.

To be honest they worked quite well. Getting old ones out to replace them was another story.

Regards Tyrone