V1jet

Yes.I know about his web.I bought Cline Regulators & rubber fuel tanks from him myself to use with a Bailey Pulse Jet.A Farmer around Esperance flys a RC Pulse Jet with his set ups & works well I am told.Cheers

MJD

My Feedback: (1)

Hooray! I have confirmation my Virus has shipped, so I should see it in about one week. I also fell prey to impulse and bought one of his 90mm engines too, the parcel was so large and the freight was so expensive, it made sense to include it in the package.

Oh man, if my wife sees this I am done for. "Who was that on the phone?" when Hubert called at 7:30am this morning to check the address.. "oh, I have some aircraft parts coming from overseas, he was just checking the address since the new postal codes don't show up in their system.."

"Parts eh.. you mean like all the parts to build one?!?". I need a new cover story.

V1jet

Well done.The Virus is Fast & the ER90 should give you about 13lbs trust static depending on reed combination & backing plate shape.Email me if you like on [email protected] I live in West Australia & have not flown mine yet but I know the er90 engine well from bench tests.Cheers & good luck.

MJD

My Feedback: (1)

I already have a locally made 90mm engine, good for about 15lb static thrust. But the ER90 was lightly used and a good deal, so I had to have it as well.

Perhaps I can fly it on both if they are easily interchanged, so the Maxjet 15 gets some air time finally.

Engine mounts are included, servos and 2 x 1l tanks built in, so other than filling the surface flaws and painting, not much holding it back from flying soon.

V1jet

Interesting about your Locally made er90.On my er90s first test I only got about 10lbs trust.I realized the reeds were very restrictive & modified the backing plate as far as I could until reeds kept braking then made my own Fuel injector to chill out the reeds much better to get get them to last one or two Gallons perfectly.I used a afterburner to add about 2 lbs also.It seems to me it should make 15-16lbs static stock if the reeds worked like a Dyna jet.As the jets get bigger reeds suffer more unless you go ARGUS.As 400kph gives about 1psi ram air I have been told thin reeds will bend back and you get a flame out.Leave it with less thrust static & in flight it will come back to 15-16 lbs thrust.
As I have not flown one yet I dont know whats going on for shore.I just go with my hart on this.I cut slots into my backing plate to get more air in & more fuel back into the reeds to cool them.I believe the afterburner would not work if the front end got all the air it wanted like a Jet Bill fast jet.I think ARGUS reeds could solve this problem.I see many ARGUS PJs have combustion instability so there design needs to be well thought out.
Three Dyna jets = 12lbs thrust and are 3 times bigger in circumference around the tail pipe to Huberts 55mm exhaust Fast Jets on Nitro/Propaline Oxide give 20lbs thrust.3 Jet Bill Pjs Fast Jets on petrol give about 15-16 lbs I think so one er90 should give the same.Its just the subject on ram air that effect that I cant be shore on until I get flying my jet.
After that perhaps I can make other improvements & hope I have not wasted all my time up to date.

MJD

My Feedback: (1)

Bear in mind the 15lb thrust figure comes from the maker - I don't have any means to measure force on the bench, so the validity of that figure remains to be seen.

V1jet

Its about the max you could expect so it may be right.The last er90 I got from Hubert came with a backing plate exacly the same as one I ended up with so they must be on top of it now.He changed the intake shape & added 5mm to the tail cone & this one tops at 13.25lbs static thrust.Thats Very good I think.With my fuel injector spraying back at about 140 deg angle into the reeds I get about 50% throttle use without over heating anything.Just hope it works in flight yet.
I put a Nitro Spark plug up front right in the fuel spray out of the hot chamber & found this starts much smoother now also.Less pops & bangs.

MJD

My Feedback: (1)

Here's one thing of many I don't know - with the fuel dialed back on the bench, sure you're going to cook reeds pretty quick. In the air, is there any more tolerance for the lean condition with the internal and external air flow?

V1jet

Some I think.It cools the outside lots & this matters the most.Zanin dont use ram air at all as its only .7psi at 200mph anyway.Just makes tunning more difficult on carburetor set ups.They use Petrol also. If a PJ is set up with full power static then the ram air can perhaps make a flame out at high speed when you throttle back .Thats what I am told anyway.I found my er90 had less thrust (about .5lbs) at 200kph with a Leaf Blower & this was because of the drag over the outside of the jet.I can throttle from 3lbs up to 14.5 lbs in 200kph air now & not have reeds run cold at all but below about 7lbs the reeds run out of tune with each other and then chip very fast.Reed less PJs can be throttled easy and fully as you know.
I find Bench testing the er90 with a leaf blower it runs a bit hot as you dont get the same cooling power as in the air.This is because radiation heat expands out past the leaf blower air flow line.I bent the er90 when I put a aluminium plate around it ho hold that radiation heat in.It glowed bright red.

V1jet

Far out .
If you ever want to go RC Pulse Jet dont use Lipo batteries.My Max Pro ECU was shutting down the jets fuel pump because the Lipo batteries are noise sensitive to vibration.Putting in a 2500w 6.6V Life battery fixed everything.I like the Max Pro ESC as it has full speed control that I found some dont like E-flight ESU's.

flyinfool1

My Feedback: (2)

I am getting closer to getting the AMA to allow modern Pulse jets in the USA.

I just keep watching this thread and a few others on pulse jets and drooling......

MJD

My Feedback: (1)

I am planning to power the pump/ESC with an 1800 mAh LiFe pack, and a separate healthy sized pack for the receiver. Need a few ounces nose weight anyway.

Model is progressing well, although I've had to deal with a few little things along the way. e.g. the profile of the base of the vertical stabs doesn't match the airfoil, I had to grind a new arc about 3mm deeper in the center of the fin. The blemishes (I willingly bought a "reject" so this is not a reflection on the model) took a few days. At this point I need to buy some bits and install the elevon linkages, then I can mount the vertical stabs and get on with finishing.

V1jet

Best of Luck with this.If US rules on this are done good RC Pulse Jets over there will Boom.

MJD

My Feedback: (1)

Thanks. I have a great site.. huge field available.

Canada's rules are quite sensible - unless they've changed since I talked to the last committee chair that is. They don't differentiate between turbines and pulsejets, use the same safety code including rigid fuel cells, fuel cutoff etc. The Virus complies with it all. The only caveat is sensitivity to noise and the need to find a suitable site, which I have. So I'll be flying safe but offensively loud. Sounds like perverse fun to me, can't wait..

MJD

My Feedback: (1)

Ran the ER90 yesterday. WOW!!!!!!!!!!!!!

Four runs, took a bit of fiddling with the throttle curve to get fuel flow right, and a bit of practice on how much air. The thing just thunders, way more intense than a Dynajet, it rattles your chest when you stand downstream. We laughed our heads off after every run. No problem cooling with a leaf blower, the combustion chamber was cool for a good 1-1/2" behind the reed bank and the reeds were fine afterwards.

My buddy took video, but it needs editing and I am waiting for a copy. Video does not even remotely manage to convey the sound and feel.

V1jet

I know what you mean about standing down wind.I love my er90 to.You got to try a afterburner one day to.Easy to make & today I got 15.25lbs static thrust out of it.Nic Rollond in Esperance WA sent me this video of his Hobbyking Pulse Jet on a Mach Racer Kit Delta with 5lbs thrust on Methanol.Evan this hoots.
https://www.youtube.com/watch?v=TTc6MmHRlsQ

MJD

My Feedback: (1)

Beer-soaked Canadians running the ER90 on a frosty Sunday evening.. https://www.youtube.com/watch?v=yW_85lMnPxo

vasek

My Feedback: (4)

Geez, gotta love those Canadians hillbilies LOL

V1jet

Latest tests on a er90 and now getting 16lbs static thrust.Modification was a 1972 idea never tried on pulse jets until now & it worked.Videos to come after more testing.

V1jet

er90 mm RC Pulse Jet just got more thrust.16-17 lbs Thrust

https://www.youtube.com/watch?v=GuNo...m-upload_owner

flyinfool1

My Feedback: (2)

WOOOO HOOOOOOO!!!!!!!

I just got word that the AMA has approved a new set of Pulse Jet rules.

The new rules will be posed up on the AMA website in the next few days.
I will wait for that just in case there are any changes from the last draft that I saw and I will post the new rules up here also.

I think most of us will be happy with the results.

Now where is that credit card........

MJD

My Feedback: (1)

I can see Herr Leubner getting a few sudden orders.

V1jet

Well done on getting PJ rules updated.Not easy.I just finished tuning my ER90 PJ engine and now runs better than ever.On a bench anyway.To test fly my INFERNO I need to go bush 100s of miles to a Salt Lake.Thats OK but with no test pilot but myself I just stuck to doing engine modifying.I think its all paid off to as this er90mm PJ has never run so good.Holes cut into the Big .3mm reed topped it all off.15lbs static & 13.5lbs with the 200kph Leaf Blower running.Starts easy evan on 100% kerosene in 30+ deg hot day.Throttles back to 8lbs perfectlyMy own fuel injector sprays fuel 130 into the reeds for added cooling and power.Stock SS backing plate has cuts & slots everywhere to help all this.If you have a er90 try this reed idea.Get a big .3mm reed & grind out a hole as big as you can to soot a small .2mm reed.The side walls on the big reed are 2.5mm .Trim the small reed to make shore you have a 1mm valve overlap all round.
https://www.youtube.com/watch?v=EYAv...m-upload_owner

MJD

My Feedback: (1)

Ya Chris, got the lathe all cleaned up and running at the shop now, so can make bits. Time to look at that 130 degree setup of yours.. gotta be ready for spring with the Virus.

flyinfool1

My Feedback: (2)

I am planning to get an ER90 and either a Virus or Super Scout.
Just because now I can.....

I will have to go back and study all of the various mods or even just start with it all stock.