Small and cheap hydraulic power pack for maintenance

MacWorld

MacWorld

Tractorologist
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Since the hydraulic accessories are not moveable when disconnected from my tractor (chute rotation, etc), I want a small (and cheap) power pack to be able to move the cylinder as I need.

In hand I have
- a 3/4hp electric motor
- many power steering pumps from mark 2 vw's. Those build around 1000psi which is more than I need
- a single spool valve without float since I bought a kit from a 1655/1855 and installed the valve with float on my 1655 to add the 3rd spool

I will probably use 1 or 2 portable camping propane tank as reservoirs, I will weld NPT bungs for input and output and also a big one, 2" probably as a filler port. That will help fill the implements if they are empty and prevent the pump from running dry.

I did assemble the single spool with the 2 ends, new o-rings everywhere and proper length bolts.

I don't know the power requirement of the power steering pump but I guess it's way higher than what a 3/4hp could do therefore I will try by reducing the pump's rpm. Since I have a standard bolt pattern on my 1655 for the PTO speed reduction, I will re-use this pattern and I will be able to test with the 9" (or 10"?) pulleys I already have. Those are W-size pulleys, it's easy to get other sizes and I simply have to drill the 3 holes of my bolt pattern.

Here is what I have accomplished so far.

First I found a channel that is the exact right size to use for mounting the pump!
IMG_8116.jpg

Then I machined a replacement hub for the pump to use W-sized pulleys and my bolt pattern
IMG_8124.jpgIMG_8125.jpg

IMG_8127.jpgIMG_8128.jpg

The pump looks tiny!
IMG_8129.jpgIMG_8130.jpg

Next step will probably be to make a frame to join the pump's bracket and the motor.
 
If it is a 2 way cylinder, which I am sure it is, use 2 couplers with a hose between them. Hook the couplers to the cylinder hoses and you can move the cylinder either way. Just be pushing oil out of one end back into the other.
 
Indeed that would work but that doesn't allow testing how the mechanisms works. When I assembled my 270° rotation chute I had to use the tractor to test if everything was working properly. The goal is to do that without having to burn fuel (and with a quieter power source).

It's also another interesting project at a small price since I already have most of the components.
 
MacWorld said:
Indeed that would work but that doesn't allow testing how the mechanisms works. When I assembled my 270° rotation chute I had to use the tractor to test if everything was working properly. The goal is to do that without having to burn fuel (and with a quieter power source).

It's also another interesting project at a small price since I already have most of the components.
Click to expand...
My kind of thinking! Carry on, I'm lurking!
 
Made some progress during the holidays, the frame is made, the bracket for the power steering pump and also the adapter to convert from M16x1.5 o-ring to 3/8 JIC. This kind of adapter is available but not at a reasonable price and most of the time made of aluminium and I prefer it in steel for durability, weight is not a concern.


Here is the general layout, there will be one camping propane tank between the spool valve and the pump.
IMG_8198.jpgIMG_8199.jpg

I had to make a reversed handle... Well I don't know how to call this! On the Massey the valves are installed with the tubes under but for ease of assembly I prefer having them on top for this project. I will probably buy a proper handle to replace the bolt I installed temporarily.
IMG_8200.jpg

And finally the adapter. It's made from a VW Passat (or Audi A4/A6 etc) drive axle bolt which is M16x1.5 and a 3/8 NPT -> 3/8 JIC adapter that I turned to fit together and I silver brazed them together. We'll see if this brazing will hold the ~1000psi the pump should make. The alternative would be to TIG weld them together. Of course I turned the feature as it was on the OEM tube to install the o-ring.
IMG_8203.jpgIMG_8204.jpgIMG_8207.jpg
 
Its starting to take shape! I made my reservoir with a camping propane tank... Don't do that, find another alternative. Those tanks are really thin, it's a PITA to weld something to them. 1.25" NPT filler neck with a custom wing nut plug, 1/4" NPT return port at an angle toward the bottom and a 1/2" NPT feed at the bottom with a custom 90° to the same shape as my power steering pump's input port.

I borrowed again the flaring tool from the hydraulic shop that sold me 3/8" tube and lent me this tool when I added a front circuit to my 1655. He also even gave me about 24" of pre-bent tube that he considered strap which I used completely. I made all the tubes required. I also installed and wired an interruptor directly on the motor.

Last thing I made is the handle for the spool valve, I bought a 5/6-18 ball knob (KBC Tools 1-903-43604 ~$2.61 US) and threaded a rod both end for it.

Here are some shots with incomplete tubes
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And here what it looks like at the moment
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This is my custom handle.
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And on this one you can see all the tubes and the feed port between the tank and the pump.
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Next thing will be to figure out the real ratios I need for the pulleys, make a finger guard for the belt/pulleys. I also ordered a link belt which I will use as a tool for my projects for testing purposes and to figure out the length of v-belts I need to buy. Currently my motor draws about 9.7A when the spool valve is activated and nothing is connected (pumping to a dead end) and it's rated 11A on the sticker. May be a rule of 3 could help me find the pulley ratio I need. Anyway I will probably order more split steel pulleys like the 9" I have on my tractor, probably 5, 6, 7 and 8" and I will test until I stall the motor at which point I will back a size.

I also tried it on my snowblower chute rotation cylinder and it works great! A bit slow but not that much!
 
The pump is working! I changed the pump's pulley to a 6" and it seems appropriate. The motor is not stalling but on a dead end it's drawing about 12A. It's rated for 11A at full load, overloading it is acceptable for me as this is for short uses and pumping against a dead load is not expected. It doesn't slow down at all, I guess the pump's relief valve is helping a lot on this.

I've uploaded a video on YouTube (first time, tell me if something is wrong). Keep in mind it was really quiet in my garage, the noise level sounds way worse more than it actually is. Hydraulic power pack from power steering pump
 
I don't have a spool, but I have a complete handle set up for one spool.
 
@MacWorld

Check and see what the service factor is on the motor. If it has a factor of 1 or higher, you'll be ok at 12 amps. The motors service factor tells you how much the total amp draw can be and not damage the motor for use of the motor over the marked amp value for short periods of time. The motor may also have a thermo overload built into it, if it gets too hot it may cut off until it cools off enough to run again.
 
jason silliker said:
Do you have anymore of the Massey valves? I'd love to add the third spool but they're scarce here.
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Sadly no, I had bought a used 2 spools kit some years ago, I installed the float on my 1655 and the other one is on this power pack /:
 
Texas Horses Hogs and Deeres said:
@MacWorld

Check and see what the service factor is on the motor. If it has a factor of 1 or higher, you'll be ok at 12 amps. The motors service factor tells you how much the total amp draw can be and not damage the motor for use of the motor over the marked amp value for short periods of time. The motor may also have a thermo overload built into it, if it gets too hot it may cut off until it cools off enough to run again.
Click to expand...
I certainly will look into this out of curiosity but given that I should "never" have to use it at full amps I don't worry too much even if it's not with a great rating honestly.

The spool valve is open center valve (small restriction therefore lower amps when not actuated) and the goal of this power pack is to actuate accessories for testing purpose only. I should never have to run it against the relief valve and even more, the accessories it's meant for are low requirements like turning the chute or eventually the spout angle.

Added to this, in theory the pump builds around 1000psi which is more than the tractor makes (~750psi AFAIK), I guess if I use it in the same context as the tractor's pump does, it shouldn't be full load (as it is against a dead end) even for lifting the accessories!
 
I checked yesterday, the SF is 1.15 on this motor, seems it's a better motor than I thought!

Also the power pack had is first real use since I am working on my custom cover for my blower's chute rotation mechanism and I have to make a lot of tests to make the cover not interfere with the chute. It's a nice tool to have!
 
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