|
|
Post by wannabebuilderuk on Dec 10, 2021 5:48:43 GMT -5
Lol I had to do something similar for my round to rectangular adapter, had to use a bar clamped to a sheet bender as the top part was too big to allow me to fold lol
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 11, 2021 3:41:37 GMT -5
  I used a 1.5" X 2" square tube between 2 sawhorses and beat it until it was square. Making rings that fit inside and outside of these tubes helps in a huge way for making the flat material cylinders. I wish I had cut more. Steve |
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 11, 2021 6:32:54 GMT -5
 Usual little snags and hiccups but moving along. Expert welding. LOL. Ugh Steve |
|
|
|
Post by wannabebuilderuk on Dec 11, 2021 12:51:28 GMT -5
We all have to start from somewhere so don't worry about it.
If you're not happy that it'll hold I'd recommend grinding it back down but not all the way, fill the main holes visible then slowly go around doing spot welds that overlap slightly to get a consistent stacked pennies look.
Ben
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 13, 2021 6:58:27 GMT -5
I actually can do this, and have for a while! This machine... It's too big. It does not have a .030 feed wheel set for the .030 wire I have. It feeds the wire on a .035 wheel but no matter how fast I move or how low I set the feed the bead piles up like crazy and is inconsistent. So I will drag my smaller machine over here and have at it. I am an idiot and should have done that from the start. Still going tho, clamps, straps, fitment, alignment, design changes, beer, cursing, etc. All looks good as of now.
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 14, 2021 0:39:08 GMT -5
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 14, 2021 7:31:47 GMT -5
Spark plug feedthrough. Had shopmate weld it. :/ Whatever plug the Tacoma uses     Why did I not have the compressor output cut in the combustor wall?!?! Aggh. |
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 21, 2021 18:28:26 GMT -5
It's time to start the control systems for the engine. Oil, fuel pressure what sensors are you using? Oil temp sensor? Just standard automotive sensors?
Pressure reading inside the combustor?
For the tach I've ordered a E3X-NA11 and a diffuse fiber.
I do have the K thermocouple and breakout for an arduino.
Pump pressure controlled via PWM through typical DC motor controllers.
This will be read by an arduino initially but possible moving to a pi at some time.
Anything else I've missed?
Many thanks,
Steve
|
|
|
|
Post by racket on Dec 22, 2021 1:27:21 GMT -5
Hi Steve
Yep , use as many automotive bits as possible , oil pressure is a must have along with combustor P2 pressure , fuel pressure is handy , so is oil temp ..................but try and fit a total pressure pitot in the jetpipe as its invaluable for tuning the jetnozzle size when used in conjunction with the mandatory jetpipe thermocouple's temp readings , gotta know the temp coming out of the engine so we don't kill it .
Cheers
John
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 30, 2021 1:59:00 GMT -5
What are the typical pressure transducer ranges? 0-50psi P2 and 0-15 at the turbine exhaust?
Fuel I imagine is 0-100psi on the 044?
AB just PWM it and tune the curve along with rpm, P2, EGT.
I have the typical HV transformers (I believe Racket recommended in a previous thread)for the spark plugs, cylinders with the flattened side. Tips? From Amazon reviews it is better to stay under 6v even though it is sold as 6-12v. I have tried reading all the threads but there seems to be no definitive setup. I see in wannabebuilderuk posts two of the rectangle units and a spark gap. I'll mess around with them. Tune the gap and a small film cap in the input I think.
AB injector - why not just a 3/8 capped tube with 8X1mm holes sticking up in there? A 8mmX1mm slit? No holes and a pinched off end to the pipe cut at 45 degrees in the center? Of course all these facing the turbine. Do the cones and rings provide any advantage or are they just creating resistance in the pipe? I have a threaded socket in there I suppose I can try each in time.
Fuel injector - Needle valve on the bypass for nice idle and PWM the pump for the full range to 100%?
What's the ST-50 ballpark rpm at idle 40k? 80K at 100%? I'm sure I will be just getting it to self sustain and dropping the PWM until it flames out w/o propane and going from there.
Woah so may questions as this is moving along. Sure there will be futzing and drilling and data gathering. Probably pretty close to popping it off with the propane start.
Is there a sticky I missed?
Many thanks.
Steve
|
|
|
|
Post by racket on Dec 30, 2021 15:57:26 GMT -5
Hi Steve
Lotta questions there , but here goes with some answers :-)
Yep , P2 0-50psi , P4t 0-15psi , 100 psi for fuel , and your A/B setup should be OK .
Ignition ...........whatever you can cobble together.
A/B fuel injection , flexibility with this but copy a successful design .
Our engines use a lotta fuel at idle so no need for a fine adjustment .
ST-50 max rpm , its an old design so a max of 1450 ft/sec for the comp tip , so depending on its exducer diameter it'll be different , but more like <70K at 100% and idle rpm at whatever corresponds to a P2 of ~5 psi , don't try for a very low idle as it'll probably end up in a "hung start" scenario where things will melt down :-(
Hope this helps
Cheers
John
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 30, 2021 20:18:40 GMT -5
Yes, all the help has helped! I'm frustrated with the welding and will be happy to move on to the programming and controls where I am in my realm of comfort.
Thanks thanks thanks.
Steve
|
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Dec 31, 2021 2:00:33 GMT -5
Still at it.   Thanks again for all the help! I am almost done with the sheet metal hell. Steve |
|
stevie
Junior Member
Joined: November 2020
Posts: 55
|
Post by stevie on Jan 1, 2022 0:47:04 GMT -5
Ignition. OMG. The little step up transformers.
Insane.
I got these transformers:
And these bucks:
Set the bucks to 4V 2A output.
I am dazzled blind just looking at it for a millisecond. Very loud pops. Unbelievable.
The spark is incredible. That being said I got resistor type plugs so it really tones it down through the plug. I'll get some NGK 4554 non resistor plugs and just clip the ground bar off level with the electrode.
Ow my eye.
Vid:
|
|
|
|
Post by wannabebuilderuk on Jan 1, 2022 5:55:54 GMT -5
Very nice, practically a taser wired up to that plug lol. I'd recommend not using anything with a high resistance (plug or ht lead which is the carbon core type) as I did for my first tests and it overheated the modules  |
|
