HX 82 102/255 " Money Pit "

[CH3NO2]

You're doing a thorough job on your R&D Andy!

[slittlewing]

Hi Andy,

As far as speed controllers go, that looks like a nice one! However... I had a quick scan on the website and I don't think that it would be possible to do closed loop control with it easily. It seems that controller is designed to give you lots of information on the motor current/voltage etc, but aside from that it still needs an input from somewhere.
The website says it can accept an analog input, so potentially you could try and invert the signal from a pressure sensor and scale it appropriately, but that doesn't sound too straightforward?

I think microcontroller based control is the way to go if you want closed loop!

Cheers

Scott

[enginewhisperer]

you can feed a micro's input into the VESC to do closed loop based on pressure, etc and have the advantage of a good motor controller design, but it might be possible to implement pressure based control directly.
The controller is pretty configurable.

[slittlewing]

Yep I think getting the microcontroller to do the loop closing would give more functionality (e.g. PI control, more accurate, easily adjust the "setpoint"), then feed to the controller.

Probably the only way of implementing pressure control on the unit itself would be to create a "throttle map" based on the inverse of a pressure sensor input. This would be proportional control only.

I.e. If your pressure sensor gives 0V at 0bar and 3V at 5 bar, configure the controller that 0v->2.5v is 100% Speed/Trq, then taper Speed/throttle off accordingly above 2.5V
That assumes the VESC Analog Input mapping is configurable to that level (and can interpolate on a negative gradient).

[Deleted]

Hi Guys

I deffer to you guys, I am not sure yet how it will all be set up.

I have seen and have down loaded code that would enable me to do this





Code to the VESC it's self, with a normal ESC you would either use a servo tester ? RC Controller or Micro controller ? using PPM function ?
to do the same thing ?

It has also been suggested that as the unit knows it's self, what amp, voltage and RPM It is doing, it would not be hard to control the unit with something like this and code







www.ebay.co.uk/itm/G1-4-Transducer-Sensor-0-0-5MPa-for-Hydraulic-Pneumatic-Pressure-Gauge-Oil/122345063428


Am not sure myself, it's more learning :-) But some i have been talking to that work with these on Battle Robots don't seem to think it's hard to do ?

Guessing time will tell, unit the engine is built and pumped up with pump etc, it is hard to know whats going to happen. I could rig up some kind of rig, to mimic what
mite happen when oil warms up with running engine, but once it doing the real thing, things could not be the same ?

For now i will get the pump and motor unit together, do some flow and pressure testing, and go from there


All The Best
Andy

[slittlewing]

Hi Andy,

The first picture will be the standard wiring for the VESC in order to use "analog input" (or a variable resistor/hand throttle etc). What you really want to do is to control what voltage goes into the ADC_EXT pin, probably using a microcontroller and the sensor you list on ebay (rather than with a potential divider as shown).

With a normal ESC, you would need to mimic a servo signal. Most microcontrollers (like arduino) can do servo control and therefore output the right signal, but with the VESC one this isn't required as above.

I am planning on using those same sensors (but the 0-1.2MPa version) with Arduino soon to do similar closed loop control (but with DC Motor and PWM). I would think it would be really easy to do achieve what you want with an Arduino Uno (they are only £8 too!)

Cheers

Scott

[Deleted]

Nov 16, 2018 4:51:03 GMT -5 slittlewing said:

Hi Andy,

The first picture will be the standard wiring for the VESC in order to use "analog input" (or a variable resistor/hand throttle etc). What you really want to do is to control what voltage goes into the ADC_EXT pin, probably using a microcontroller and the sensor you list on ebay (rather than with a potential divider as shown).

With a normal ESC, you would need to mimic a servo signal. Most microcontrollers (like arduino) can do servo control and therefore output the right signal, but with the VESC one this isn't required as above.

I am planning on using those same sensors (but the 0-1.2MPa version) with Arduino soon to do similar closed loop control (but with DC Motor and PWM). I would think it would be really easy to do achieve what you want with an Arduino Uno (they are only £8 too!)

Cheers

Scott

HI Scott

to use that wiring, you have to up load extra code to the VESC, This is the point that has been made to me, the VESC is code driven, not like old style ESC, yes you could tweak some of the perpetrators, but this thing can run
algorithms

I may be wrong, or at least the people helping me ?

All The Best
Andy

[slittlewing]

Fair play, only one way to find out
I had a little look on the source code on github linked off the website, it does have throttle curves (so could maybe map the pressure sensor voltages directly to this) and the unit can also be operated in Current Control mode. That might also be the simplest option, because current should be proportional to the resistance (and therefore oil pressure).

Cheers,

Scott

[monty]

Andy,

I'm watching this with great interest. I'm planning to use this VESC controller to operate the starter/generator on my fan engine.

On a separate subject I've concluded the Holset turbine may be a better option for me. I definitely prefer the thrust bearing arrangement to the Garrett. Can you confirm for me if the compressor nut is a left hand thread? It appears to be in all the pics I've seen. If you'd be willing to share the dimensions of the shaft it would allow me to compare some ideas without spending $800 just to take some measurements. ;-)

Monty

[racket]

Hi Monty

That wheel on Ebay is expensive, maybe this one is better www.dieselpartsdirect.com/3535977 Cummins owns Holset

Cheers
John

[Deleted]

Hi, Yep its left handed

here is the wheel, they have a few on the site

www.turborebuild.co.uk/webshop/prod_3456937-Holset-Turbocharger-Turbine-Shaft-and-Wheel-HC5AHX808285-Turbo-3521034.html

Let me know what else you need to know

All The Best
Andy

[monty]

Nov 22, 2018 14:45:17 GMT -5 andym said:

Hi, Yep its left handed

here is the wheel, they have a few on the site

www.turborebuild.co.uk/webshop/prod_3456937-Holset-Turbocharger-Turbine-Shaft-and-Wheel-HC5AHX808285-Turbo-3521034.html

Let me know what else you need to know

All The Best
Andy

That price is pretty tempting.....and I already have the bearing bits...

John....buy my paperweight!!...I'll make you a deal!!

Besides....we all want to see your engine run!!!! 

Monty

[Deleted]

Hi Guys

Thanks to Bruno at Alien Power System, helping me out with the project. I got the motor and VESC today

The motor is rated up to 2400watt, 230kv, I will be running it at 21 volts, at between 3000 and 3500 rpm






I can not believe how compact the VESC is, it is rated to 60 amp, 240 for short periods, just starting to get my head around programming in C






The pump should be here soon, looking forward to getting it all together and pumping some oil



All The best
Andy

[Johansson]

Sweet!

[Deleted]

Hi every one,

So things have slowed a little on the CNC side, Terry has been working on getting work out the door before the holidays.
But he sent me this picture the other day....



He has made the tool to hold the defuser back plate on the 4th axis indexer, and will be starting to cut the turning vane this weekend.

I have also been working on learning about live steaming on YouTube... the plan is to stream LIVE the testing of the new engine, and the building of some of the
parts, oil system etc.

Just need to ask, what kind of time of day suet's, I am think some thing 11 O'clock GMT ?? early morning one side of the world.... evening other side ?
Saturday morning ? Please let me know what time works for you

Here is a test I have done of the effects on screen, seeing how it all works



So other day this arrived, having worked in hydraulics for 30 years. I have to say it is one of the best turned out pumps i have seen Want to say big thank you to the company for supporting me

How soon to have it together with it's motor soon. It has a CCM of 3.12 a rev, it will be driven between 3500 rpm to 4000 rpm, about 10.5 LPM to 12.5 LPM depending on how things preform
The relief is set to 10 Bar at its lowest from the factory, but if needed it is easy to swap out the spring and drop it a little.

If needs be I can drive the pump up to 6000 rpm, which would give me up to 18.5 LPM the motor is good for 9500 rpm so plenty of area to play around with.

As the plan is to use this high spec 0/20 motor sports oil from Miller oils, i am hoping to get at least a stable 6 Bar oil pressure.... time and tinkering will tell






All The Best
Andy