richardm
Senior Member
Joined: June 2022
Posts: 335
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Post by richardm on Feb 18, 2024 18:23:16 GMT -5
Did you try an automobile spark plug ? Be it just to confirm your exciter is working ok? I dont know what type of aircraft igniter plug you have Some older types were air gap type. Quite similar to an automobile one. Newer more modern have a semiconductor material between the electrodes that must be ionized to conduct and deliver a spark. Those require voltages above what we build can deliver Some 20 Kv and above That semiconductor will also erode and eventually it won't work at all. They are time limited. On walk around we use to check for those by listening for the characteristic "ping" Quite often only one of both igniter was working and had to be replaced I have a couple of those brand new and my home made exciter won't work with them but scares me on an automobile plug.
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Post by wannabebuilderuk on Feb 18, 2024 18:57:21 GMT -5
Did you try an automobile spark plug ? Be it just to confirm your exciter is working ok? I dont know what type of aircraft igniter plug you have Some older types were air gap type. Quite similar to an automobile one. Newer more modern have a semiconductor material between the electrodes that must be ionized to conduct and deliver a spark. Those require voltages above what we build can deliver Some 20 Kv and above That semiconductor will also erode and eventually it won't work at all. They are time limited. On walk around we use to check for those by listening for the characteristic "ping" Quite often only one of both igniter was working and had to be replaced I have a couple of those brand new and my home made exciter won't work with them but scares me on an automobile plug. Diesel is hard to ignite normally which is why john and others do a diesel petrol mix and I plan on running it on kero once I get some, before the igniter burnt out it wasn't combusting the spray of diesel as probably not enough energy for it. I'll test again once I get some kero
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richardm
Senior Member
Joined: June 2022
Posts: 335
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Post by richardm on Feb 19, 2024 6:37:12 GMT -5
Kerosene is a little easier to ignite than diesel but it packs a little less heat per gallon... Early jet fuel were a blend of gasoline ( 65% ) and kerosene ( 35% ) It was easier to ignite and work well in very cold temperatures but was a much more dangerous stuff than jet fuel used today. If you re going to mix diesel with gasoline careful not to get that cooked lobster complexion with no eyebrow... www.youtube.com/watch?v=7nL10C7FSbE
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Post by wannabebuilderuk on Feb 19, 2024 14:48:35 GMT -5
Received the 5 hv modules with only 1 faulty, think I've found the source of my problems as upon testing my 20kv 2a diode it appears to be shorted as allows voltage to flow both ways with a small drop so perhaps this is why the modules are frying. Time to wait for one to ship from China I guess, would love to use the 20kv 100ma ones andym uses but extremely expensive so 20kv 2a it is again.
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richardm
Senior Member
Joined: June 2022
Posts: 335
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Post by richardm on Feb 19, 2024 16:31:50 GMT -5
DVM won't work to test an Hv diode. From a web site about HV diodes..
" HV Diodes are made up of many series connected diodes of lower voltage ratings. They will look like an open circuit in either direction to an ordinary DVM ".
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Post by wannabebuilderuk on Feb 19, 2024 18:17:40 GMT -5
DVM won't work to test an Hv diode. From a web site about HV diodes.. " HV Diodes are made up of many series connected diodes of lower voltage ratings. They will look like an open circuit in either direction to an ordinary DVM ". I know that which is why I did the higher voltage test method. youtu.be/Cx8Q5crqKawIt flows both directions so has shorted and basic acting like a resistor and thus damaged the modules
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richardm
Senior Member
Joined: June 2022
Posts: 335
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Post by richardm on Feb 19, 2024 18:29:03 GMT -5
And couldn't charge the cap either as you had no rectified pulses Hope that fixes your ignition problem
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Post by wannabebuilderuk on Feb 19, 2024 18:52:38 GMT -5
And couldn't charge the cap either as you had no rectified pulses Hope that fixes your ignition problem The cap still charged, these modules out out pulsed DC not ac, the diode helps stop the cap flowing back into it but now it just acts as a resistor which does more harm.
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Post by wannabebuilderuk on Feb 21, 2024 18:23:18 GMT -5
Oil test tomorrow, just occurred to me the pressure switch I bought so long ago might be a min 50psi and bypass spring is 40psi.. Might have to modify the switch spring pressure if that's the case lol
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Post by racket on Feb 21, 2024 20:32:28 GMT -5
Neat and tidy :-)
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Post by wannabebuilderuk on Feb 22, 2024 12:13:17 GMT -5
So after dropping a nice bit of oil on the floor as gasket blew out after I blocked the pump outlet to see if the Bypass spring and channel would work I realized the channel is too small for the flow and since I cannot be bothered breaking the loctite between the brass and aluminium I needed a way to clamp it roughly in the original position how I first milled the slot which resulted in this tomfoolery... Surprisingly it seems to work quite well a little bit chatter but a lot easier than dremeling lol. It comprises of a random 1" air fitting which happens to fit perfectly in the hole with a PVC pipe sleeve to act as a spacer held securely by the short zip tie with the aluminium slid onto the air fitting and secured by clamping one of the brass fittings against a jaw with an allen key for spacing resulting in the plate being parallel to the chuck 😁
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Post by wannabebuilderuk on Feb 22, 2024 14:58:13 GMT -5
Bit extra to help the gasket seal, hour of back and forth and hands impregnated with aluminium splinters.
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Post by wannabebuilderuk on Feb 24, 2024 8:51:35 GMT -5
Well only a little leak around the bypass channel due to me making the wall a little too thin to properly seal on the gasket but what engine doesn't leak! Steady 50psi when cold and fully blocked which should be plenty(assuming the bearings provide enough restriction, can always increase bypass spring to higher pressure if needed?), have also set fuel cutoff oil switch to 40psi so I didn't order the wrong one lol. really impressed with the viaircorp compressor motor runs bang on 23a...does exactly what it says on the tin 😁 imgur.com/DDlqAEU
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Post by wannabebuilderuk on Feb 25, 2024 5:01:15 GMT -5
Also picked up a FLIR thermal camera for £80, normally £200 second hand although now need an iPhone or adaptor as use Android lol
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Post by wannabebuilderuk on Feb 26, 2024 13:33:42 GMT -5
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