I'm back

[thebuildist]

I alluded to it an another post, but I've been desperately avoiding the final stage of my loader project. Big-time procrastination, finding anything to do other than tearing apart the hydraulics on the 4020 AGAIN.

I feel a little guilty every time I think about the tractor, so I've been avoiding thinking of it, and that means I kinda avoid CCIGT as well.

But I'm back. I think my mind has finally had enough time to get over it's little hang-up and let me proceed. Tomorrow morning before work I drain the oil down and start to work.

Here's what I've accomplished in the last several months while I avoided working on the loader. I have:
Designed and built a custom mini chest of drawers for Christmas ornament storage
Fabbed up a headboard, footboard, and a remote control panel to get a hospital bed working (the bed mechanics all worked, but it was missing the control panel)
Survived Omicron Covid
Made a bushcraft knife from scratch (joint project with my son-in-law)
(I learned you can DIY black oxide coating using nothing but vinegar, peroxide, and distilled water. Very cool.)
Assembled, cleaned, set up, and customized a new Chinese "stitcher/patcher" leather sewing machine
Made a leather sheath for the bushcraft knife
Removed an unwanted 6' x 5' x 10" high brick hearth and patched in the floor with slate tile
Installed 3 replacement windows here at my house. (2 more, and I'll have all new windows in the entire house.)
Installed an onboard 120V power system in my truck, including adding a secondary battery and a permanently mounted 2000 watt inverter. (Control panel in the cab center console, one outlet in the control panel, another outlet in the pickup bed wall near the tailgate. Engine doesn't need to be running to use the AC power)
Installed DIY power windows in my truck
Fabbed and installed a custom winch mounting system as described in my previous post
Designed and built a custom drillbit storage/index tray
Performed the annual spring landscaping/planting as directed by my Director of Plant Operations
Swapped engines on a self-propelled mower, including fabbing a custom extended length blade adapter with integrated pulley (to retain the self-propelled function) The donor engine was off of a pressure washer and its crankshaft was more than an inch shorter than the original engine.

So it's not like I'm sitting around doing nothing. But dang, I've got to get the loader project behind me! Besides, it'll be so much fun to play with when it's done!

And I'm currently enchanted with learning watchmaking. Not building from scratch, but having the tools and skill to be able to completely service any mechanical watch. (disassemble, clean, inspect, repair, reassemble, lubricate, and electronically test for proper timing) But I'm making myself wait on the watchmaking until the loader is done.

Some people have accused me of having a short attention span, but I don't know WHAT they could mean...

[Timj]

Holy cow Bob, slow down.
Isn't it easy to put off projects you are not wanting to do? Sometimes a little break helps clear your head and then you can get back into it. Good to hear from you.
Tim

[Eugen]

Oh wow! Bob, that's a lot of stuff you got done, so you definitely are justified to delay the work on the loader. I'm glad you're back, even to say hello if for no other reason!

[Harry]

I've done that too Bob. I've got projects partially completed and the next step is involved so I do other things until I'm ready to jump into them. Look at the positive and the many things you did accomplish. All in due time has been my attitude lately, Life gets in the way!

Keep the Peace
Harry

[DavidBarkey]

Like the rest said , wow you have been busy . " Director of Plant Operations" Love that one . I am so steeling that.

Dave

[propane1]

Hehe. Love that emoji.


Noel

[thebuildist]

Whelp, I took the plunge. The first step is to test the priority flow divider valve to see if I can find a happy adjustment.

In a nutshell, there are two paths I can take from here: either remove the TCV and modify it such that it has a power beyond port, and then feed the new loader valve from that power beyond port.
Or install the "priority flow divider" valve that I've already bought.

The TCV/power beyond option is fairly foolproof, in that it follows what Case did with the 646. All the oil leaving the TCV next heads to the loader valve for use in loader functions. But it's the most work, since I have to remove the TCV, completely disassemble it, do all the machining, clean out all the grit, and put everything all back together. And it's the most risk, as I could conceivably destroy my TCV by way of design error or machining mistake. (Not that I personally have ever goofed anything up, but I hear that it can happen to other people... ) The other downside is that the loader valve only gets pressure equal to the TCV's relief setting, in my case about 2100 psi. I think that 2100 is enough for what my loader needs, but just barely. As best I can calculate, my bucket tilt cylinders will need all of 2100 psi to tilt the bucket back with 1000lbs on the cutting lip. So I THINK it would be ok? But I'd rather have a bit of margin.

Meanwhile the priority flow divider valve would be a little easier to install. I just need to re-configure my new hard lines, both of them shorter than they are now. Working with hard lines is a pain, and I'm not happy to do it, but it's not as bad as reworking the TCV itself. And since it creates a completely separate circuit from the TCV, it can have a higher pressure relief than the TCV. Something like 3000psi seems reasonable. But the priority divider valve does have a potentially big downside: I don't know if its variable control is going to be granular enough to actually work in this application. It's rated for 20gpm, and I'm given to understand that these priority valves work best when operated near their rated flow. My flow at the divider valve is only about 9 gm. So my fear is that I may struggle to find a consistent workable sweet spot on the adjuster knob where the TCV is getting enough flow for normal operation, but there's still enough diverted for adequate loader operation. The adjustment knob reads from 1 to 10, and I'm afraid it may be a situation where a setting of "5" gives ALL the flow to the TCV, but then dialling it up a tiny bit to "5.1" suddenly cuts "all the flow" over to the loader valve and starves the TCV.

But there's only one way to find out for sure. So this morning, true to my decision, I pulled out the existing loader valve and piped in the new priority flow divider valve upstream of it. I ran out of time for today, so I didn't get to test it, but that'll be tomorrow's task: I have a loopback hose in place that routes all the oil from loader valve's "out" work port directly back into its "in" work port, and I'll drive the tractor around and see if I can find a setting on the priority valve's adjustment knob where I have "enough" flow to the TCV for workable driving, while simultaneously diverting "enough" flow through the loader valve.

Of course I'll have to judge the flow of the oil through the loader valve by sound, since I don't have an actual cylinder hooked up to it. But I at least ought to get a good sense of how "touchy" the divider valve adjustment is, and satisfy myself that there is a "wide enough" range of transition between "the TCV has all the flow" and "the TCV has zero flow."

I'll post back tomorrow with results.

Bob