Q&A Forum
Hi Eric , ok the VRFB 90 1/2" hydraulic flow valve has a Poppet valve with a needle and seat arrangement inside it . Interesting drop curve for the valve Will be interesting once you run it again.
Hi Eric , any new news how the speed is responding ?
What does the pump valve look like inside shape and size , I'm just being curious here ???? VRFB 90 1/2" hydraulic flow valve ???
Hi mach, here https://www.hydrapac.it/hydraulic-valves/flow-regulator-valves/90-flow-regulator-valves-vrfb-90 you can see in details what is a vrfb valve. Finally I have finish the gear on stepper engine but I dont have resolute my problems, I think I have to do some tests with differents value of kp and ki. Next days I will do some test with the support of jostein that is very kind and patient! My problem is that brake doesnt work correctly, also with manual control, but work fine only when I test it in brake setup page.
Hi Eric , any new news how the speed is responding ?
What does the pump valve look like inside shape and size , I'm just being curious here ???? VRFB 90 1/2" hydraulic flow valve ???
Some news about geared stepper engine... It's only to align gear shaft to hydraulic valve.... Transmission ratio 0.5..
Hi, the valve is VRFB 90 1/2" hydraulic flow valve, is a precise flow regulation valve, although the first 4/5 turns are unuseless because doesnt give any load to engine. This afternoon I will place a photo of how I Connect the valve to stepper engine...
I will use plastic gears (pom) because the price is pretty good and also because the torque trasmitted is very low.
Hi Eric , OK , plastic gears wear/strip very easy, that is my opinion . I have no idea what a VRFB 90 1/2" hydraulic flow valve looks like inside or outside , so you cannot load up the engine the first 4/5th of the turn of the valve handle.
Sounds like its either its on of its off and nothing in between with load ? OR am i misunderstanding what you mean by , " first 4/5 turns are unuseless" ???
Is the inside of the valve a ball valve straight through hole arrangement or a barrel that travels up and down or a sluice gate valve arrangement that allows the oil to flow through it?
Hi, the valve is VRFB 90 1/2" hydraulic flow valve, is a precise flow regulation valve, although the first 4/5 turns are unuseless because doesnt give any load to engine. This afternoon I will place a photo of how I Connect the valve to stepper engine...
I will use plastic gears (pom) because the price is pretty good and also because the torque trasmitted is very low.
Hi, I think that the velocity of stepper motor is regulated only by stepper driver and software. Software have Maximum 2000steps/sec both at 24v and 50v. If you change volts or ampere, I think that change only the torque.
I think the better choice is to put 2 plastic gears between stepper Motor and flow valve. Is quite simple, the only problem can be the vibrations..
Hi Eric , you are absolutely right about the software and ST-M5045 Micro-Stepping Stepper Motor Driver controlling the speed ( PWM) , I stand corrected and i am wrong.
Nice pictures keep them coming. Pump valve =16 teeth/stepper_motor =32 teeth gearing ratio arrangement will be nice to see working and increasing the speed and halving the time factor in response.
What does the pump valve look like in shape and size , I'm just being curious here ?
Why are you using plastic gears ?
Bye
Next daysI will build a gear for stepper engine and I Will make some test! I will post here results, impressions and answers 😁
Thanks a lot
Eric
Hi, yes you are right with regards to the speed. Anyway, if you drag the slider in the brake setup quickly from 0% to 100% brake, then you see how fast it is :-).
How is it working now?
Infine i have bought 2 plastic gears (rs online) mod. 1, one 32theets and one 16theets, thus the transmission ratio between stepper motor and flow valve will be 0.5 and the velocity to go from 0% to 100% brake (4 turns) must be about 0.4sec (with 400pulse/rev and 2000step/sec)
Hi,
So you are getting closer to a good setup. It is still about 1.5 seconds from no brake to full brake, which is slow. If you are below 0.5 seconds, best to have below 0.5 seconds. You may add a gearing.
Anyway, with slow valve control you need low Kp and Ki. It will still work but it means the regulator will be less able to adjust to sudden changes.
Indeed any setup with Ki will have a static error, only Ki can fix that. You are on the right track, you can experiment a bit more with Kp and Ki, but better to increase the speed of the valve control.
Hi jostein,
I make some calculations, but If I havent make an error, with 1200steps from 0 to 100% with 400pulse/rev and 2000steps/sec the time necessary or valve to go from 0 to 100% it's about 0.6sec not 1.5sec
I have only few photos...now I upgrade the System with flow valve instead of vmp 12 spring valve, and works better..
Hi, I think that the velocity of stepper motor is regulated only by stepper driver and software. Software have Maximum 2000steps/sec both at 24v and 50v. If you change volts or ampere, I think that change only the torque.
I think the better choice is to put 2 plastic gears between stepper Motor and flow valve. Is quite simple, the only problem can be the vibrations..
QUOTE , " Member : eric91- Hi, I use 36v 5a external supplier for nema 34 engine. Look stepper online.com, have a lot of stepper Engines. I choose high torque nema 34 Motor because vmp valve have the resisteance of spring. With normal flow valve is necessary less torque. "
Hi Eric, that is why I asked what voltage are you using to step your stepper motor.
quote, "Technical Parameter - ST-M5045 Micro-Stepping Stepper Motor Driver Supply Voltage: 24~50Volts DC & Output Current (peak): Min 1.0 Amps, max 4.2Amps"
My thinking is if the stepper motor driver can control 50 Volts DC maximum to the stepper motor that will give you more speed and torque than what will 30 volts DC going to the stepper motor. Is my thinking wrong ? OR right ?
Example - if you get a 12 volt wiper motor and supply it 12 Volts DC ( & pulling 4 amps approx with a load ) from a car battery charger it will spin nicely with plenty of speed & torque , then if you change the voltage on the charger to 6 Volts DC it will slow down in speed and torque drops down considerably on the wiper motor. Just my observation and thinking the same will apply to stepper motors and voltages supplied to them.
Sounds like I'm going to be faced with the same problem as from no load to full load is 14 approximately full turns of a shaft on the H&F hydraulic water brake dyno just to turn a cylindrical shaped V grooved valve to control the water outlet.
Post a few pictures of your dyno setup Eric please and thanks.
Bye