Homemade drill drive boring bars

[RayF]

I tend to think that if the bearings have a decent crush on them like 50 or 6 thou they will handle the pin being tightened on them. If you are a bit nervous about it the way to be sure is machine up some top hat bushes.Just rebate the bore a bit so they sit flush.I've done a lot of them. Machine them out of 4140, oversize. Bring them to a red heat and quench them in oil and final machine them with a ceramic tip. I have a number of machine with them and they are going 7 to 8000 hours no worries.
Steve,an O ring around the outside is good. We also cut a groove in the end cap to take an O ring. It bolts up against the end of the bore and acts as a seal to retain the grease. I might have a pic somewhere.

 

[RayF]

Here you go. These are Hitachi EX3600 bucket caps.

 

[OldandWorn]

Here you go. These are Hitachi EX3600 bucket caps.

Ray, These caps look like they are made from scratch. Is this a totally different design than from the factory or are you duplicating the factory caps and just adding an o-ring groove?

 

[RayF]

Tom,the Hitachi factory design is nothing more than very basic pin with a locking tail and no bearing in the bucket and no cap. No protection for the faces and the bucket bores wear rapidly in a mining enviroment. Myself and a workshop manager made up this floating pin system for his fleet or PC650 and 1000 Komatsu diggers 22 years ago.We went from boring a bucket a week to one every 3 month's. The effect was so dramatic that I would say almost every mining bucket made in Western Australia uses a similar set up. I can't claim all that much credit though as we used the Liebherr system as a model.
So these days I machine up the bosses and the caps for my line boring clients when they manufacter a new bucket. After its made I go in and line bore it.

 

[OldandWorn]

Sweet! Thanks for the explanation. Looks like bar stock, you must have a nice big saw too.

 

[RayF]

I have a decent saw but we get them profiled out of plate

 

[OldandWorn]

Fooled me . I saw the caps in the background with a bit of rust on the O.D. like correctly sized stock with a light finish cut.

 

[Old Magnet]

The "Nervous" solution sounds good to me. Top hat bushings = flanged bushings that I was referring to previously. Really just providing a liner to replace missing bore material, not the usual wear bushings. Thanks again.

 

[steve loving]

Old Magnet keep us posted do you have a supplier for the flanged bushings or are you going to make them.

 

[steve loving]

I have a decent saw but we get them profiled out of plateView attachment 82561

Ray that new mill will be nice working on those

 

[Old Magnet]

No, I'm not equipped to produce the bushings described......still digesting the info. Closest I got at one time was looking into flanged drill bushings but they would be a special order item.

Do I detect a proposal in there???

Thanks

 

[steve loving]

Im going to see whats out there in flanged bushings this weekend on the internet.

 

[RayF]

No, I'm not equipped to produce the bushings described......still digesting the info. Closest I got at one time was looking into flanged drill bushings but they would be a special order item.

Do I detect a proposal in there???

Thanks

Mate,cmon over this morning and I'll spin a couple up for you

 

[Old Magnet]

I'd love to but the freight bill on 270 lbs would be a bit much. LOL

Interesting that not long ago I was working with a fellow with a lame D6 out of Perth.
Apparently a gold mining (small) operation. Nice fellow, was happy to get his tractor going again. Regards

 

[Old Magnet]

Aaaarrgh!!!! That's 230 lbs, not 270.....I'm fat enough already.

 

[steve loving]

old Magnet here is an interesting bushing mgf. www.acmeindustrial.com they have got a lot of bushings. Also look at H.E.F usa on the menu on the left look at pel high load bushings Steve

 

[Old Magnet]

OK, I'll check it out.....thanks again.