Mixing........

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SimonWeel
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Mixing........

Post by SimonWeel »

Right, flashed the most recent firmware and then tried to configure master / slave mixes, like with 'ye ole stock firmware. Read the manual. In the mixes setup, you can insert things to control other stuff with one channel. So I guess this is the way to do it, but I just don't know how? The radio is used to control the RC4WD 4200XL digger, which operates quite simple. The digger has a hydraulic valve block with four valves. Three to control the hydraulic rams and one relieve valve. This one opens more or less depending on the state of the other valves and is to prevent damage to the oil pump. For example (stock firmware), mix one looks like this:
State: Act
Master: Ele
Slave: Aux
Offset: 100
Uprate: 100
Dnrate: -100
SW: Nor
How would this translate to a mix with the er9X firmware?

SimonWeel
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Re: Mixing........

Post by SimonWeel »

Nobody??

Right, lets refrase the question. The bucket on the digger is operated with the right stick, moving left/right. It's hooked up to channel 1 of the receiver. The hydraulic relieve valve is hooked up to channel 8 of the receiver. If the bucket is not operated, this valve should be 100% open. If I move the right stick left/right to control the bucket, the relieve valve has to move opposite. I.e. the servo's on channel 1 and 8 should counter each other.

On the radio, I made a mix for channel 1: 100%, AIL and I added -100%, CH8. That doesn't work. I'm stuck. Don't know what to do. Anybody?

Simon
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KAL
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Re: Mixing........

Post by KAL »

You have to think the other way around ...

for ch1: 100% Ail (first mixer line)
for ch8: -100% Ail (8th mixer line if mixer empty)

Klaus
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SimonWeel
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Re: Mixing........

Post by SimonWeel »

KAL wrote:You have to think the other way around ...
Right, now we're getting somewhere. Ok, the relieve valve (CH8) has to be 100% open with the sticks neutral. So for CH8, I create a mix with 'Source: full' and 'Weight: 100". Then I add another mix with 'Source: AIL' and 'Weight: -100'. That does the job - almost.

When I move the stick all right, channel 8 outputs 0%, i.e. the relieve valve is closed since the one for the bucket is 100% open. Good. Now I move the stick all left. Hmm, channel 8 still outputs 100%, where it should be 0%. So I have to create something that closes the relieve valve when moving the stick in either direction?

Simon
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jhsa
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Re: Mixing........

Post by jhsa »

To make things clear, 0% is stick in the middle, +100% is stick fully to one side, and -100% is stick fully to the opposite side, right?

Ok try this.

Program a 5 point curve:

c1 0, 50, 100, 50, 0

Now in the mixer:

Ch8 100% AIL Curve (c1)
Adjust values for the right throws.
See if it works

João
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SimonWeel
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Re: Mixing........

Post by SimonWeel »

jhsa wrote:Program a 5 point curve:
c1 0, 50, 100, 50, 0
Now in the mixer:
Ch8 100% AIL Curve (c1)
Yes! That did the trick. In the mixer, I added something similar for ELE and THR. So the mix for CH8 looks like this:
CH08: +100% FULL
-100%THR Curve (c1)
-100%ELE Curve (c1)
* -100%AIL Curve (c1)
For the last one, AIL, I had to set 'Multiplex' to 'Multiply' instead of 'Add', although I don't know why....

Now we are going to make things difficult. I'll explain what the current setup is, what problem it causes and how I think it can be solved.

As written before, the digger has three hydraulic operated components: bucket, dipper and boom. The hydraulic pump runs at a constant speed of 23% of its maximum. If the hydraulics are not used, then a bypass valve is opened (CH08) to prevent damage to the oil pump.

Now what happens if I move the ram of the bucket at maximum speed (100%): the bypass valve closes completely. If the ram is moved at 50%, then the bypass valve is closed 50%. So oil pressure is sustained. Now I move the boom and dipper at the same time and both at 100%. Then the bypass valve is closed, but the oil pressure drops by 50%. I.e. the rams move at half speed. And consequently, if boom, dipper and bucket are operated at the same time at 100%, the oil pressure drops to a third.

What I want is a sustained oil pressure, no matter how many valves are opened and regardless the amount they are opened. And that's where we are in luck. Since the oil pump runs at 23%, we need to spin it up if more than one valve is opened. i.e. if all valves are open 100%, we need the oil pump to spin up to 71% to sustain oil pressure.

The math looks like this. If the combined stick movement for dipper/bucket/boom is between 0-100%, then the bypass valve should be closed accordingly 0-100% and oil pump runs at 23%. If the combined stick movement for dipper/bucket/boom is between 100-300%, then the bypass valve should be closed 100% and the oil pump should spin up to somewhere 23-71%.

How are we going to do this?

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