Dempster No 12 Cross head babbits

[Centex Windmills]

Working on a 8ft Dempster No 12 and the cross head casting is in good shape but the babbits are worn through. Has anyone on here repoured these before and be willing to share how to do it?

Brandon

[windybob]

I've done at least a jillion. lol

[Centex Windmills]

Any tips or steps? never delt with babbits, tried to just find another cross head but they all seem to need them repoured at least from what I've found.

[windybob]

Those are really bad for wearing out. 95% of those I've seen are shot. I can tell you how I do it, but maybe it would be easier to run them to a machine shop and have them sleeved with brass. Let me know. You're probably not the only one here that is interested.

[Centex Windmills]

I thought about brass sleeving them but didn't know if that would work, I have a machine shop I've used in the past just not sure if they would be able or willing to do brass sleeves.

Would you just basically do press fit brass sleeves?

How much tolerance or slop should there be in the cross head?

I've tried to stay as true to original as possible, so part of me wants to try babbits if they are not to hard.

[windybob]

You do not want a tight fit, that's for sure. Working babbitt is purely subjective. If you have a mechanical background, it may be easier than for someone who does not. I have an old 8 ft head that I use for a jig. proper setup is imperative. It might take an hour to set up, but 10 seconds to pour. If the pour fails, then you start over again. I need to run an errand. I will be more specific when I get back.

[Centex Windmills]

Ok thanks i am fairly mechanical minded. From welding fabrication, car rebuilding and engine rebuilding

[windybob]

Keeping in mind that the top side of the crosshead runs down hill, install the 2 guidrods in the case, and slip the crosshead on them. put the guide rod tie on the top. this will space the guides proper. See how the crosshead centers up on the rods. Of course, you should have the babbitt melted out, and cleaned up good first. You might check the guide rods, and make sure they are straight first. If the crosshead has been riding on the cast, up against the rods, they won't be round any more. You will need to replace them. Otherwise, the new babbitt will lock up on them, and you won't get them apart.

[windybob]

Once things look pretty good, you should eyeball the crosshead to see how you center it on the rods. Make a mental note of distance between the rods, and crosshead. I made a spacer to put under the crosshead on the one side. That way it sits pretty good in the case. Remember, the top of the crosshead runs downhill, don't let it throw you off by trying to put the top of the crosshead horizontally flat.
Once you get an eye on how things are going to sit, you need to start with the putty, to seal areas that will leak.

[windybob]

Put some putty around the bottom. if you need to use a spacer then use it before the putty. Once you putty it, you don't know how the spacing will be, unless you do something to keep it from moving. The factory babbitts these on their side, ergo the holes with the babbitt coming out is on the side. You can put some masking tape on these. Also, the holes at the tray that collects the oil from the oil tabs on the gears need plugged with putty. You can drill those out later.