APS/Ω Gas turbine bike build

[Mobacken Racing]

Yet another frustrating hour spent on trying to get the engine tachometer for the bike to work, but at least it was the last since I swore to never spend another minute on it again. From now on I´ll rely on the boost pressure gauge (which I have had to do anyway so far since the tacho never worked), it is amazing that neither Olov or I have been able to build a reliable tachometer despite trying all kinds of tricks to get one working.



It feels really good to know that I won´t have to get upset about a tachometer any more.

Luckily not all went bad tonight, I connected a pressure switch that will activate the water injection pump at a set P2 pressure. While playing around with it connected to the shop air I managed to blow up the 0-3bar pressure gauge so I just ordered a WIKA 0-4bar gauge to replace it with. JU-02 will hopefully bottom it out some day.



Cheers!
/Anders

[Mobacken Racing]

I just got the Arduino PWM fuel pump controller working!



After a couple of evenings in the sofa soldering and tinkering with the PWM box I had loads of trouble when it came to uploading my friend Olovs Arduino code to the card, I must be jinxed somehow when it comes to computers because it is supposed to be dead simple but after trying it on three different computers and getting three different error messages I gave up and let Olov do it.



It turned out that the Arduino Nano card was also acting weird so with a new card and Olovs computer the code uploaded like a charm, when I got back home I connected the throttle and a 12V fan as a test. It worked perfectly and the idle potentiometer worked as well (it adjust the lowest PWM setting)



I also got the new P2 gauge I ordered after breaking the old one with the shop air compressor.



Cheers!
/Anders

[saltwheels262]

[quote  I must be jinxed somehow when it comes to computers
[/quote]

I don't think you jinxed on very much. I'm sure the computers will come to you. If that's your only problem~~~ you really don't have any. IMO

As much as you can do and what you do ; you are way in front of many of the commercial shops that I know of.

I don't have to askiss anybody , just amazed at what you do.
Fantastic good job.

Franey

[Mobacken Racing]

I don't think you jinxed on very much. I'm sure the computers will come to you. If that's your only problem~~~ you really don't have any. IMO

As much as you can do and what you do ; you are way in front of many of the commercial shops that I know of.

I don't have to askiss anybody , just amazed at what you do.
Fantastic good job.

Franey

Thank you very much Franey.

Troubleshooting computers is luckily something I don´t need to do since I have friends who can help me out there. It is one of the very few things that can send me off into a spitting rage in only a couple of seconds, so I try to avoid it as much as possible.

[Mobacken Racing]

I didn´t get much practical work done today but I think I have a goodie coming up. At least I fitted the throttle module to the bike, the transistor was mounted directly to the aluminum dirt shield for better cooling.



During the early bench testing of JU-01 I used a 12V fan to push air through the engine for preheat and cooling after a test, now with the bulky air box removed I can find room to permanently mount it to the bike.



I drew a simple fan bracket in Inventor and started the 3D printer, so early tomorrow morning it should be finished.



This will be great if it works like planned, I will connect it through a relay to the electric throttle micro switch so when the main powre is on and the throttle released the fan will be blowing. This way it will provide air for the propane preheat and help cool the engine down after a run. Sweeeet!

Cheers!
/Anders

[manta22]

Anders;

A suggestion for that transistor mounting, especially in a vibration environment- use a small Bellville or wavy washer under the nut to maintain clamping pressure between the TO-220 mounting tab and the heat sink (aluminum dirt shield). Without that washer, as the temperature changes between the two surfaces, the clamping pressure will change due to thermal expansion. For vibration resistance, put blue Loctite in the nut threads- but you already knew that. 

Regards, Neil  Tucson, AZ

[Seldom Seen Slim]

Got something like a thermal/anti-corrosion grease to put between the body of the transistor and the bike?  Either that or mark the spot with bri :roll:hgt orange paint so it's easy to find when something goes dead from corrosion. . .

As always, don't ask me how I know this.

[Mobacken Racing]

Those are two very valid suggestions, I´ll get them done the next time I visit the workshop. Thanks!

Loctite isn´t needed since I use a nyloc nut, if that vibrates loose I have more problems with the bike than just a wiggly transistor...

[Mobacken Racing]

I found this one waiting for me in the printer this morning, a tight press fit for the fan just as intended. I´ll drill a hole for the cables through the side of it later.



Cheers!
/Anders

[Old Scrambler]

Too Cool .............or is it: Cool Tool

[Mobacken Racing]

During the last couple of late evenings I have been working on fitting the 12V fan to the bike, it wasn´t so easy to find a place where it can blow into the compressor intake without blocking the incoming air when the engine is running.



When I tried the preheat I couldn´t get the propane to light, was the fan too weak to get enough air moving through the engine after all? Nope, I found that it was the placement of the spark that was the problem. After fitting a 1mm copper washer under the spark plug it lit the propane in a second with the fan running. Sweet!



As you can see the new 4 bar P2 gauge has been fitted, I really like the clean look of the Wika gauges without the usual secondary psi scale that clutters it up.



I have been doing a bit of thinking about the oil pressure lately, I have been having trouble with a very high oil pressure when the oil is cold only to drop down below 4kg when it has heated up. I use a semi-syntetic 10W40 oil now so I´ve decided to change it to Mobil 1 0W30 and see if the pressure stays more constant.



Cheers!
/Anders

[manta22]

Anders;

I see one of your gauges is a liquid-filled type. Do you know the trick to getting those to read correctly?

Regards, Neil  Tucson, AZ

[Mobacken Racing]

Anders;

I see one of your gauges is a liquid-filled type. Do you know the trick to getting those to read correctly?

Regards, Neil  Tucson, AZ

Hi Neil,

Only "trick" I know is to make sure the breather valve is open. I am intrigued, tell me tell me!

[manta22]

That is the trick, Anders. Not many people know to do that- they just complain that their gauge is no good.

Regards, Neil  Tucson, AZ

[Mobacken Racing]

That is the trick, Anders. Not many people know to do that- they just complain that their gauge is no good.

Regards, Neil  Tucson, AZ

Easy to forget, this gauge has a small flip valve on top so it can be closed again if the gauge is put in storage.

Tonight it was time to connect the fuel pump controller and see whether it will work or, more likely, release its magic smoke...



With the power wiring into and out of the PWM controller made everything was ready to be tested, but first I had to bypass the oil pressure switch to start the fuel pump without the oil pump running.

https://youtu.be/G-KUR4kqPaU

That went well indeed, I just have to recalibrate the idle potentiometer a bit since the fuel pump started spinning at the 2/3 setting.

Next up is to draw up and print a cover for the tachometer diodes, it is needed both to shield the diodes from damage when I work on the engine and to keep sunlight away from them which might mess up the reading.



Cheers!
/Anders