A Tandem Cub

[sawdustdad]

Originally Posted by cheesedawg82

Absolutely awesome build. I've really enjoyed reading this, and I've really learned a lot, although a few things do have me curious, and I hope you don't mind my questions on your thread.

1. Hydro Pump - In hindsight, what are your thoughts on simply running an automotive power steering pump off of the Starter/Generator belt and using the same or similar plumbing? This seems simple and cost effective, and it would allow you to mount the filter up front near the engine, higher than the tanks. You did an amazing job on the pump installation, it looks awesome for a loader or a machine that would get see constant use of the hydraulics, but is it overkill for this particular purpose? Do you think a simple Linear Actuator would have done just as well without all the hassle? (Note - Please don't take that question as an insult, if the particular purpose was quality craftsmanship and the additional time and expense required to do so was worth it to you as the builder, you nailed it. I'm curious of your input on the pros and cons).

2. Tandem Axles causing tire scrub during turning. - Could you build a linkage to the fluid drive manual bypass control valve of the rear transaxle that's accessible from the seat? The rear would then theoretically run like a tag axle and nothing would bind. Would this be helpful to you at all? Would lightening the pressure relief spring on the front unit (or stiffening the rear) accomplish the same thing mechanically? How about the ability to engage and disengage both front and rear hydraulics? How do you engage the front bypass to push it? (Note, this afterthought may or may not help you, but I can definitely see it as useful if someone else were to follow suit with a different frame configuration).

Just now seeing your questions, cheese...

I considered mounting the hydraulic pump to the PTO, allowing it to be turned on and off. I actually built the mount for that, but abandoned that in favor of the rear mount method to keep it hidden and free up the PTO for other tasks. It would have worked either way.

As for the linear actuator, it would work but getting one that can push 2000 lbs and work reasonably fast, and not pull 50 amps proved problematic. If you reduced the capacity and/or the speed, it might be workable. Part of the decision was to learn how to do it hydraulically. I'd previously built a dump trailer with a linear actuator.

Both hydrostats have auto relief valves, so pushing is no problem. Since the axles are solid mounted and don't operate independently, disabling one axle could strand the machine if the driven axle lost traction due to uneven terrain. Having the second axle providing power generally prevents this. The tire scrubbing is not too bad. It does limit the turning radius, however. By no means a perfect arrangement, but it does work well enough to be a useful machine.