Soil Mixer 2019/Controller: Difference between revisions
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*Needs to cycle a dc motor for cement dosing | *Needs to cycle a dc motor for cement dosing | ||
*Water mister solenoid | *Water mister solenoid | ||
=Electronics= | |||
*Mega 2560 | |||
*Relay Shield (3A) | |||
*External Relays boards for >3A | |||
*Fused Battery Connection | |||
*High Pressure Switch | |||
* | |||
=Hydraulics= | =Hydraulics= | ||
==Hydraulic | ==Hydraulic Calculations== | ||
'''Hydraulic Cylinder Volumes.''' 2.5x12x1.25 Cylinder <br/> | '''Hydraulic Cylinder Volumes.''' 2.5x12x1.25 Cylinder <br/> | ||
Cap End Volume:((2.5in)/2)^2 * 3.14 * 12in =58.875 cu in <br/> | Cap End Volume:((2.5in)/2)^2 * 3.14 * 12in =58.875 cu in <br/> | ||
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|0.76s | |0.76s | ||
|} | |} | ||
==Hydraulic Diagram== | |||
<html><iframe src="https://docs.google.com/presentation/d/1ScpptOBN8ljrSdcZd_iyKdNUiskhitRu5VUAuOlNQTg/embed?start=false&loop=false&delayms=3000#2" frameborder="0" width="960" height="749" allowfullscreen="true" mozallowfullscreen="true" webkitallowfullscreen="true"></iframe></html> | |||
[https://docs.google.com/presentation/d/1ScpptOBN8ljrSdcZd_iyKdNUiskhitRu5VUAuOlNQTg/edit?usp=sharing edit] | |||
==Hydraulic Circuit Simulation== | |||
===20Nm Load on Motor=== | ===20Nm Load on Motor=== | ||
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|} | |} | ||
==Old Crappy Hydraulic Simulations== | |||
===12/19/2019 (Getting Better Models)=== | ===12/19/2019 (Getting Better Models)=== | ||
{| | {| | ||
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In both the above videos the setting of the two pressure relief valves changes motor speed and cylinder travel speed. I try to set it to minimize flow through main bypass valve. | In both the above videos the setting of the two pressure relief valves changes motor speed and cylinder travel speed. I try to set it to minimize flow through main bypass valve. | ||
Revision as of 15:07, 20 December 2019
This page includes information about the entire electromechanical hydraulic control system for the soil mixer. This is a variant of CEB Press Controller v19.01
Controller Requirements
- Needs to switch a double acting cylinder while running a hydraulic motor
- Needs to cycle a dc motor for cement dosing
- Water mister solenoid
Electronics
- Mega 2560
- Relay Shield (3A)
- External Relays boards for >3A
- Fused Battery Connection
- High Pressure Switch
Hydraulics
Hydraulic Calculations
Hydraulic Cylinder Volumes. 2.5x12x1.25 Cylinder
Cap End Volume:((2.5in)/2)^2 * 3.14 * 12in =58.875 cu in
Rod Volume: ((1.25in)/2)^2 * 3.14 * 12in = 14.71875 cu in
Rod End Volume = 58.875 cu in - 14.71875 cu in = 44.15625 cu in
| Flow Rate | Extend Time | Retract Time |
|---|---|---|
| 5 GPM | 3.06s | 2.29s |
| 7.5 GPM | 2.04s | 1.53s |
| 10 GPM | 1.53s | 1.15s |
| 12.5 GPM | 1.22s | 0.92s |
| 15GPM | 1.02s | 0.76s |
Hydraulic Diagram
Hydraulic Circuit Simulation
20Nm Load on Motor
Check out these videos first. 20nm load derived on mixer main page in design review section
| Series Circuit | Sequence Valve Circuit Closed Center Valve | Sequence Valve Circuit Open Center Valve |
|---|---|---|
| 13.25 GPM through valve. Motor speed up to 4K RPM on cyl retract. When cylinder bottoms out, fluid has no path to tank and flow stops through the system. | Whereas the third circuit has difficulty retracting the cylinder under heavy motor loads, this circuit has no such condition. Flow rate through motor significantly decreased when cylinder is traveling as all cylinder flow is lost to tank. | If the motor is loaded more than 20Nm(maybe 40Nm, the cylinder cannot retract. I'm not entirely sure why this is yet. If the motor is loaded at 20Nm then the circuit behaves well and all flow from cylinder goes to motor during cylinder travel. |
Old Crappy Hydraulic Simulations
12/19/2019 (Getting Better Models)
| Series Circuit - 2500PSI Bypass Valve | Sequence Valve Circuit 1 Open Center Valve | Sequence Valve Circuit 2 Closed Center Valve |
|---|---|---|
| Motor gets no flow when cylinder bottoms out | 1000PSI Sequence Valve Setting | 1000PSI Sequence Valve Setting |
| Sequence Valve Circuit- Changing Variables | Sequence Valve Circuits with Loaded Motor | Series Circuit with Loaded Motor |
| In this video the sequence valve is set to ~500psi and I change parameters in the circuit including external torque on motor. | Sorry about the audio. Interesting results. The load on the motor may be low because the hammers pivot out of the way. I'm not sure how to go about calculating it but I could figure out the minimum diameter of the rotor (hammers pivoted) and start there. |
12/18/2019 (Lesser Quality Models)
Using demo version of FluidSIM
| Series Circuit with three way flow controller on motor | With flow (q) and pressure (p) during the simulation |
|---|---|
| Using a pressure relief valve in the simulator as a sequence valve. | Outlet from cylinder valve is plumbed through a check valve to motor. | ||
|---|---|---|---|
| high pressure remains at the pump outlet throughout simulation. something must be missing from the system or the valves aren't set right. | Increases motor flow during retraction of cylinder. Interesting effect- I didn't expect it. This circuit isn't great because pump outlet pressure is constantly above 2700psi. |
In both the above videos the setting of the two pressure relief valves changes motor speed and cylinder travel speed. I try to set it to minimize flow through main bypass valve.