MJD

My Feedback: (1)

I now have the pipe mounted at two points, the original rear bracket, and a tie-wrap type mount farther up to support the weight. The pipe is clamped in firmly and sits on its own, nicely aligned with the header and standing off about 1/16". So now the header should have nothing to complain about.

#2, intended as home for my SJ .50, sits in stasis still - I stuck the cowl plug in the first mold half, #$%#& ^&Y^&% Q#@$#$ !!!!!!!!!!!!!!!!! [:@][:@][:@], and trashed both parts. So starting again on plug #2, and need the model as is to lay up a base for the plug again. Sigh..

MJD

p.s. ooh and check out the cool vinyl stuff from a fellow-Revver-who-shall-remain-nameless-coz-he-did-them-at-work.

combatpigg

My Feedback: (3)

That looks like it should last forever. You've got a real "fuel it & flip it" set up there, everything looks good.
Having the header break was the work of the Devil.

BiggerDanno

What prop are you running with that West?

MJD

My Feedback: (1)

Typically clipped down 8.8 props in the 8.50/8.75/9.0 pitch sizes. The prop on there is about 8.1 x 9.0. Launching is no big deal; I have my helper hold it by the tips, point it up at maybe 30 degrees and banked 10-15 to the right, a smooth push forward and it gently arcs over and rolls upright at about the same point I can think about using the elevons and off it goes. Any headaches I had before were due to the aforementioned bit of left thrust that crept in. Bad.

If the header breaks this time, I know it's the header.. there is virtually no force on it from the coupler at this point, so as long as the mounting scheme hangs on it should be good to go. The West, when anchored down properly anyhow, is truly a fuel, start and go setup and sounds wonderfully snotty on the open pipe.

I really should think about swapping out the elevon servos though.. the dreaded HS-625's, but they're still working - like that mattters, I guess they work until they stop.. and when that happens is the issue.

MJD

p.s. that's the charging plug sticking out of the left elevon servo arm hole in case you're wondering - I fish it out with a pick for charging then tuck it back in afterwards. Yes, I do inspect the internals now and again . The HS-81MG throttle servo crapped out after a handful of flights.. that ticked me off. It wasn't hard mounted, I had it stuck in a blob of silicone and the pushrod guide was also rubber-clagged, so there was some give. But I guess it can still get hammered through the wire pushrod, I dunno. Maybe it was junk out of the package. Out of an anachronistic sense of adventure I installed an old Futaba S-133 to replace it, and I have a feeling it will just sit there and do the job without fuss.

BiggerDanno

Are you launching at full throttle?
What rpms does it turn with that prop?

combatpigg

My Feedback: (3)

MJD, there was a clever throttle linkage shown here that I slowly recall. I think it was 2 pieces of yellow Nyrod joined in the middle with a coupling made out of fuel line.

mk1spitfire

Great, should be in the air again soon Mike with more vid I hope!!!

you said dreaded 625? Did i miss something?

Is filing the bladder tank like filling a normal tank? which one you running?

daven

My Feedback: (1)

CP,

Thats exactly how one of the local racers does their fuel lines here. I've found, if I stick with the Hitec 85 versus the 80 or 81, I have no issues. Have been using the 85 for close to 10 years now and it has been solid, but the 80/81 series would break gears far to easily. I think the ball bearing helps immensely.

smoknrv4

My Feedback: (11)

Cool stickers dude, looks good!

Ed Smith

If I may make a comment on Mikes pipe set up.

As the pipe gets hot it will expand. If the pipe is hard against the header and fixed solid at the tail end then the pipe will bend and possibly break, usually at the point where the pressure fitting is screwed in. When we ran Nelson pipes in our F3D Racers we pulled the pipe tight to the header and allowed the stinger to slide in a close fitting silicon tube as the pipe expanded

See the picture. I realise that the Nelson pipe had a different configuration but the point is one end of the pipe should be allowed to move.

Ed S.

combatpigg

My Feedback: (3)

Thanks Dave. Is the HS-85 strong enough for a firewall type fuel line pincher?

MJD

My Feedback: (1)

Hi Ed - there is about .050 - .060" clearance between the header and pipe inlet. Does that sound like enough? Where it is tie wrapped to the base just ahead of the wide point, I think there is enough flex/play there. It's clamped tight at the rear, but that pylon will wiggle a bit as it flexes the sheeting underneath. Does this sound like it could still be a problem?

Danno - sorry, my tach has been elsewhere whenever I've needed it lately, but I will get numbers for you as soon as I run it again.

Mk1, that is a Jett 6 ounce short. Normally you use a syringe affair - Jett has them - to evacuate the tank before filling it with fuel. It is no harder or no more trouble to fill than a clunk tank IMHO, just different. And the difference in behaviour is all the favourable evidence you need once you run one. Re Hs-625's, several people have reported centering failure or jitteriness, a few crashes have been blamed on them.

So I should use HS-85's instead of 81's. Good to know Daven, I have a couple lying around IIRC. I grabbed the 81 because it looked big enough and the specs suggested it would do the job fine.

MJD

Ed Smith

To be safe we allowed for 1/8" expansion overall.

Ed S

MJD

My Feedback: (1)

That RIRE engine belongs in a Demon..

smoknrv4

My Feedback: (11)

I just wanted to chime in on the tune of , Screamin' Demons are a blast to fly, the more I fly mine the more I love it , its the only plane I've been flying lately, especially since flying with the boys in Orangeville, Its so smoothe, it goes exactly where you point it and can fly in any amount of wind , within reason of course, everytime I go up, I learn something new, with "flying on the edge" type flying, I love it! I just wanted everybody to know that.

P.S. I think everyone who likes to fly fast should own one, they are so cheap and easy to build, especilly since you can buy the kit again.
LOVIN IT!

daven

My Feedback: (1)

CP,

I have seen the 85 work for pinch setups, but it has to be set up perfect.

At full pinch, the servo arm should be pointing at the tail, so it can not stall out. I also suggest very flexible tubing, I like the Sig Medium tubing, which is actually a little smaller in diameter than the most Medium sized tubing. It is also very flexible and has worked great in pinch applications that I use to struggle with.

I normally tend to stick with a 225 hitec if I'm pinching a line, but have used 85's pretty successfully.

combatpigg

My Feedback: (3)

Thanks again Dave. Sounds like a HS225 would be a safer bet. I burned a servo on my 1st pincher set up. I found some RC car "DEMON" brand medium tubing today. It isn't neon purple or anything kewl like that, but it is soft. I've found that the hole in the firewall should be sized big enough to fold the tubing as the wire hook drawns it through. It takes more effort and will fry a servo if the hole is only big enough to pinch the line. I ended up needing about a 5/16" hole in the firewall, and it doesn't take too much of a tug to close the line now.

MJD

My Feedback: (1)

Does this sound like a pitch for a free kit or what? Honestly, I never paid him. Mike C.. is this your doing?

Now in all seriousness, thanks for the plug there smoknr, much appreciated. I like 'em so far too.

MJD

Mike Connor

My Feedback: (5)

Not my doing, other then I did have something to do with this kit being on the market. I personally can't think of an airplane I would rather fly.

lfinney

My Feedback: (44)

mjd

i would take your header off and throw it in your oven for 8 hours....at 400 degrees F. this is SOP at mac's products after brazing or welding, it returns the material to a near T6 state of temper..... trust me it helps alot, and a .50-.75 thou gap is right on the money for pipe to header gap. mac's will retube any of their headers as well!

MJD

My Feedback: (1)

These appear to be laser welded - I'll get a closeup shot tomorrow - so I wonder how much annealing takes place with that? Heat-treating sure won't hurt anyway.. might just do that.

MJD

lfinney

My Feedback: (44)

the tubing is always annealed before bending and port forming, but the welded headers arent often quenched after welding, which is key, anyhow a temper in the oven isnt much time wise to make sure stresses are normalised.

combatpigg

My Feedback: (3)

A heliarced part might need stress relieving, but a gas welded part wont. Just let it air cool gradually and it will never fatigue crack.

smoknrv4

My Feedback: (11)

I would agree totally, annealing it after fab is a must.

bob27s

My Feedback: (19)

I have used the smaller 81 and 85 servos for pinch lines. But I used the sonictronics thin-wall tubing at the pinch area. Also have some thin-wall tube that came from Circus Hobbies (and for those who know who that was, you know how long it has been on my peg board )