CAD Digger Bushings - Brass vs Nylon??

[dourobob]

My buddy and I are building a Caddigger 821 and we are now pricing bushings. The Cadplan specs call for 6 brass bushings that are 3 inches long with ID of 1.5 inches and OD of 2 inches. So far the best price we have been able to obtain is about $300 CDN for the set of 6 bushings.
On the MetKit specs they quote nylon bushings and price them at $8 US each or $48US for six. Even with the $$ exchange this is quite a price difference.
What am I missing here? Can nylon really replace brass in this application? What is the life expectancy of one versus the other?
We would appreciate any feedback from bushing experts and/or from anyone who has used either option in building a Cadplans Digger.

Any recommendations on sources of bushing would also be appreciated.

Thanks
Bob

 

[Anonymous Poster]

Duroguy, I can tell you from experience with digging equipment of all kinds and having rebuilt a couple of backhoes that the nylon bushings just do not have the strength to resist 'flowing" out of the bore when great force is applied. This just isn't a nylon application, in my humble opinion. Actually, some commerical hoes don't even use brass but a very hard alloy bushing that works against a hardened pin or shaft. Some of the bushings on the hoe can be greased, and some run dry, like the bucket linkage. It that case, only hardness and tensile strength will survive.

 

[JohnZayka]

Try MSC @1-800-645-7270, or www.mscdirect.com. Reference MSC #35374123, SAE- 660 cast bronze sleeve. Dimensions are 1.50" ID x 2.00" OD x 3.00" long. Price in catalog is $10.29 each. I do a lot of buisness with this company, and they are great.
John

 

[Soundguy]

I'll have to agree with the others. Nylon is going to deform and wear rapidly in this type of environment. Perhaps if they were captive bushings of some sort, maybee.

But as a comparison, the bushings in all of our heavy equipment from the loaders all the way up to the earth movers are brass.

If this is a real small light duty job, for say like a ford 1210, or a yanmar 1500 or something.. or. kubota 2200bx...you might want to try it.. heck.. for 50 $ if it doesn't work, you can always get the brass ones.

Just keep an eye on play on all pins and cylinder ends... but still wouldn't reccoment them for anything over a couple hundred pounds of distribution.

Soundguy

 

[Steven]

You can by brass tubing 2" outside diameter x 1/4" wall thickness, and just cut them to 3" lenths. did not get a price quote but this is one site to start with. <A target="_blank" HREF=http://www.lewisbrass.com/rbt.htm>http://www.lewisbrass.com/rbt.htm</A>

 

[Anonymous Poster]

Er.......not to put too fine a point on it, but in actuality the material that is used in these bushing is BRONZE, instead of brass. They use bronze for it's durability over brass. I think bronze is tin and brass combined........but don't quote me.

 

[hazmat]

CJ, you are right to put a fine point on it. Bronze is the material of choice, not brass for bushings.

<A target="_blank" HREF=http://www.mcmaster.com>mcmaster carr</A> has them for $10.29 also.

One of the OEM's for bushings & bearings is <A target="_blank" HREF=http://www.bostongear.com>boston gear</A>

Here is the catalog page <A target="_blank" HREF=http://www.bostongear.com/pdf/bearing_catalog_sections/bearings_8-17.pdf>bronze bearing pdf</A>

 

[sleepyhollow]

Hi Folks,

Bronze is a combination of tin and copper.
Brass is a combination of copper and zinc.
Hope that clears up any confusion

Sleepyhollow

 

[Anonymous Poster]

Thanks, Sleepy; I've never been able to keep that straight. I have no problem with the four best conductors: Silver-Copper-Gold-Aluminum......Sport-Cars-Go-American....I need to think of something that goes with brass and bronze.

 

[mrcaptainbob]

I used the graphite grooved bronze 1" ID bushings when I made my CadPlan 628. Used the dirt digger to clean out some growth along the pond bank, submerging it in the water doesn't hurt it a bit. Costs a bit more than the others, but I didn't want to visit that area again. I hope It lasts a good long time to justify the effort.