Case/Davis trencher backhoe

[Eugen]

Only replaced the engine Dave, it's using the original pump. As far as I can tell it moves fine and as you could see it pushes strong. I did not set the engine to the highest RPM. It should be plenty for the backhoe as well.

Yesterday I cut the eyelets off the old rod. I'll take advantage of the opportunity and put bushing in each eyelet, as they have enough wear. It will be steel bushing as I don't have any source of bronze bushing of 1-1/8 ID.

Been thinking of a jig to weld the eyelets true on the rods. Maybe from some 2x4s to sandwich the rod. Normally the end of the rod would have been turned on the lathe a small diameter like 5/8 and a corresponding hole made on the eyelet so they could fit together true.

[DavidBarkey]

https://www.mcmaster.com/products/bushi ... -bearings/
See if Canadian Bearings in Barrie can get these

[Eugen]

I'll have a look Dave, thanks! - price might be ok. I hope.

Today I tapered the end of the new rods on the grinder, getting them ready for welding.

The eyelets need to wait for bushings.

Question to you guys: saw this video on youtube, see minute 27:36

https://youtu.be/mGpYGZ2ZxB4?t=27m36s


where a guy was doing this kind of repair on a bigger rod. It was obviously a very professional shop, huge lathe and everything. He MIG welded the eyelet and heated the spot before welding it. Is it necessary to preheat?

[thebuildist]

No, the preheat in that case was only because the part is so large that it would function as a heat sink and give him a cold weld. I think the size of this part the weld action itself will deliver plenty of heat.

Bob

[thebuildist]

By the way, for doing real world work, that guy is my very favorite channel. I've watched everything he's ever done, and boy have I learned a lot from him.

My very favorite channel of all is Dave Richards old time steam powered machine shop. But that's just because it's so unique and interesting. But doesn't apply hardly at all to the real world.

Bob

[thebuildist]

What welding details do you plan to use on it? .040 mig with gas? 3/16 7018 on DCEP?

Bob

[Harry]

I watched the video and yes that is a large diameter rod the guy is welding. Preheat is never a bad idea you just do not need to go overboard with the heat. 400 to 600 degrees is plenty. Figure heating up a piece of metal quickly with an arc is quite a shock to it. The welder used flux cored wire in the video, I could see the flux fall off when grinding it. I couldn’t see his welding machine so I’m not sure if he used shielding gas. Flux core or FCAW is similar to E-7018 which is a low hydrogen weld. More penetration than short circuiting MIG. Harry

[Eugen]

What welding details do you plan to use on it? .040 mig with gas? 3/16 7018 on DCEP?

Bob

Thank you Bob! I was going to heed Dave's advice and use 7018 DCEP. Somehow I feel more confident doing that than MIG.

@Harry , the guy said he uses Hobart XL-525 Gas-Shielded Flux-Cored Wire.

[thebuildist]

I'd go the 7018 route too. If you do the same gas-shielded MIG route that Curtis does, ("Curtis with Cutting Edge Engineering") then it seems like it really lays in a lot of material very quickly. So it would save some time, I'm sure. But since I have no experience with it, and since I'd have to go buy both the correct wire and the correct gas, it would be a lot more expensive than just picking up some 7018 rods. And those lay in a pretty nice bead too.

Bob

[DavidBarkey]

@Eugen If it is a damp at all . Warm the metal up to pull the damp from the joint just before you start welding . A propane plumbers torch will be enough .