Magom Brushless Pump

[rc_farmer]

Well, i thought i would share my input on the Magom Brushless pump setup. After two months of tinkering with it, i am not impressed. I decided to post a few pics of the setup. Problem with the setup is....it keeps blowing lines on the pressure side. This was straight out the box w/o any adjustments. Thought it was the type hose, but have ruled that out. Have adjusted pressure screw to no avail.









Pump rotation, when looking at it from the rear is clockwise. Pressure side from the pump is connected to the upper port (P) on the valve block, rtn is connected to the lower port on the valve. (return to tank). I have confirmed that when the pump is rotating, oil is being pumped out the pressure side port. I have busted about a foot of hose to the point i am out of hose. As you can see from the pics, of how the tubing has swollen at some point.

STRANGE THING: when this happens, it occurs while i am operating one of the valves. As long as the pump just running, the hose tends to slightly expand, but explodes when i make certain movements on the controls.

I am still talking to Magom but this has been really frustrating to get right.

I welcome any imput.

[ihbuilder]

1) pressure relief valve ?
2) if PRV , how is it plumbed in ?
3) RPM of pump ( any reduction in to that pump ?) ?
I assume the aluminum part on the side of the pump is the tank ? The way I plumb the type of valves you are using , I run the press. side through the valves to the PRV and back into the tank . also on those type of valves , they should only turn a 1/4 turn max. Your press. could be to high and valves over traveling . call if you need to .

[bigford]

stupid question time... how hot is the oil getting? looks like the hose is getting hot
then expanding and bursting.

[ihbuilder]

Another ? , is it vented ?

[rc_farmer]

Hey Steve, Travis, here is the answer to the vented question.....

[rc_farmer]

Originally Posted by bigford

stupid question time... how hot is the oil getting? looks like the hose is getting hot
then expanding and bursting.

The oil really gets hot, but as i said, it can run without any problems until i make a movement. I filled the tank to about 1/2 as per Magom and turned the motor down too.

[avel]

WTF! Do you have a pressure gauge? Why is it so frothy? What hydraulic fluid are you using?

[Cooper]

Would definately get a gauge, that Jung pump is capable of 45 bar/ 650 psi. And possibly a bigger tank.

[sinkMe]

Think you ave way to many rpm's. I have the same pump (Jung HR7) and the bl motor from the xl 4200 digger. It is running on ca 2000 rpm. The flow on this pump is 1,3 liters/minute with 3000 rpm I believe... To much for the hose. And I think it is getting too hot very quick because of the pressure building up.

[rc_farmer]

Originally Posted by sinkMe

Think you ave way to many rpm's. I have the same pump (Jung HR7) and the bl motor from the xl 4200 digger. It is running on ca 2000 rpm. The flow on this pump is 1,3 liters/minute with 3000 rpm I believe... To much for the hose. And I think it is getting too hot very quick because of the pressure building up.

Thanks for the info, is there a proper way to measure the motor rpm.
I guess there is a fine line between the rpm and pressure setting. i can dial down the end-point on the radio for the motor rpm. I fully concur about needing a pressure gauge. I had hoped that Magom had one but they didn't offer one....so i am on the search.

There was no instruction that came with the setup.....all this is trial and error.

thanks again

[bigford]

i think rc4wd has a gauge

[Supermario]

From what your saying Rob " bursting hoses even when relief turned down " immediately tells me the relief is not in the correct part of system.
I don't know how the valve works, myself, I would resort to the old air pressure test. Disconnect the lines and verify that with each function the relief valve is also feeling the air flow.
Its like electrical terminology, the prv must be hooked in parallel not series.

[Rimrock]

My first impression is that the motor got too much rpm, and is noisy...Just tested the THS 480 Volvo, and Premacon machines on a fair last weekend, and they use the same Jung pump, but they did run very silent compared to this one..It should be possible to adjust down the rpm on the radio..
Another thing, I don't like the tank solution that Magom has come up with...I can see the idea with a compact tank, but it will lead to operation problems with such a small tank combined with a big pump like this one. I will estimated the tank size to roughly like 50 ccm, and Premacon uses a tank of 500 ccm, like x10 bigger (!). A big tank/much oil will let the oil cool more than a small tank, and one has a less problems with foaming oil / air bubbles (no good). Oil can foam when there are to much oil in the system, and things are getting too hot. It is strange as you point out, that the line explodes first when you are starting moving a valve...When a cylinder is retracted, there are more volume of oil flowing back to the tank, than is drawn out of the tank (less cylinder volume on the rod side) But if the tank is normally 1/2 filled, there should be enough space to deal with this additional oil getting into the tank (?) Well, I don't now exactly...somehow there is a sudden pressure build-up in the tank, that leads to the line bursting. Anyway, I would remove that tank and install a bigger one, like from the 4200xl.

[Cooper]

Yes cupcake is correct (Mario) ,,,,,

Try McMaster Carr, look up press gauge. $10 you will just have to figure out how you want to connect it. You don't have to keep it connected. Once you get the pressu where you want just disconnect it from the system. I'm not sure how your system is set up but like Mario said the relief valve needs to be in the system that the pressure can be diverted and not blocked. Usually the lower pressure is when the valve is all the way unscrewed. Most of these valves are a spring pushing down on a bb seat. (So to speak) the more the set screw is threaded in the more the spring compresses and the more pressure is needed to unseat it allowing oil to flow.
http://www.premacon.com/index.php/en...ystem-premacon
A simple secamatic from premacon describing the hydro system. Hopefully that may help.

[Cooper]

Sorry link doesn't work, goto premacon, service, page 2 , first thing, it's in German but secamatic is viewable and legend is in English.

[fhhhstix]

Rob’s relief is the silver block that attaches to the side of the pump. The lower port is the regulated pressure to the valve block and the upper is the relief line. With no function activated it works fine since the relief is putting back exactly what the pump is taking out but when Rob works a function all of the flow goes to the cylinder and the relief is going to close until the cylinder hits an end point like retract of a cylinder. With the relief closed and no vent Rob just put back more oil than he took out pressurizing the tank and the relief valve is now acting like a check valve. Now with the tank pressurized plus the spring force on the relief ball the pump has to produce enough pressure to override the spring and pressure in the tank therefore blowing the pressure line to the valve block before the relief opens. Rob also told me that the tank has pressure on it after the line blows which supports what I was explaining. So after this we decided the tank needs a vent and Rob needs a pressure gauge to set the pressure then life should be good, and he can adjust the speed of the pump for flow control and heat buildup.

[Supermario]

All makes sense now with the update Travis. I missed the part about the tank issue and yes even a properly installed relief can't work with the tank side pressure build up.

[Digger_Bear]

Hi Rob,

I wanted to add my input earlier but has problems login in to post.

Compared to my setup your system looks like it's running too high in pressure. I'm using 3S lipo and 60A brushless ESC and is assigned to a rotatary knob on the transmitter, if I turn the pump to 50% power I get about the same power and speed as your video, but I find as low as 20% it works fine lifting buckets full of sand.

Strangely after my pipe popped on Sunday I have replaced the pipe and now it runs a lot quieter and smoother than before.

I also notice your pump/tank has an overflow pipe, mine doesn't so guess is unvented. And the foaming of the oil I got at first fill up so think that is related to clearing the air out of the system (I might be wrong).

Ian.

[rc_farmer]

Thanks for all the input.

Ian, just as you stated, i have since turned the pump down to about 15-20%.

im going to try and bleed the lines, it may have been sucking some air froma connection i found last night too.

[Digger_Bear]

Hard to bleed the lines I found. What I did was have the excavator on the work bench then kept the bucket as low as possible over the edge. Idea the air flow to highest point which was the valve block and pump.

Not certain if air would go back through the oil like that but was only logic I could apply.