HI Pizza,

Thanks for the pics. Are those nylon bolts holding the engine to the wellnuts? What size well-nut are you using? Did you consider using the type of asymetric bolt mounting patter as detailed on Ed's website?
Thanks,,
Jim W.

4 x 1/4-20 steel bolts weigh more than airplane, nylon bolts should hold ok, most load is on wellnut. you go first - send report after 30 flights then I will try. or maybe 2 nylon in opposite corners and two aluminum bolts?

here are pics from Eda's pattern plane - notice all that carbon fiber for support. also notice homemade custom carb arms - very nice!

That is some nice glass work .
Ray - take those nylon bolts and put em in a drawer.
Nylon is NOT good in a hot environment . They will dry out and snap like a twig.

Now you tell me - you better find me some aluminum or titanium bolts - or it may fail while you are flying it and you will pay! maybe you can manufacture some alum bolts on your lathe? and sell them to everyone - I wil pay $1 each

If you send me a copy of your firewall in template form I will send you 4 aluminium bolts. I was able to find 3.5 inch 1/4 x 20 aluminium bolts from a fastner supplier. I just can't remember who. Senior moment. --john lees

Ok deal - I will send em and mail a cardboard template

I too am going to try a ZDZ40 in my impact. I wonder about balance "CG" with the heavier gas motor. Even with the 2 mini digi's in the stab and maybe the rudder servo back in the body some will it be nose heavy. HAS ANYONE CONSIDERED MOVING THE WING FORWARD AN INCH OR SO TO HELP OFFSET THIS????? --john

according to my calculations if you put an 8411sa in tail under stab with direct link 4' long or so this will offset the engine weight, everything else should go in according to instructions. there will be some additional balance adjusting capability w. ignition batt. this setup will keep rudder servo and cables out of the way so you can switch out large pipes through the canopy no problem during contests.

FYI: www.mcmastercarr.com carries aluminum and titanium bolts...they are hex head though...I use them to make wheel axles.

-mark

thanks Flyintexan, here is engine setup for best performance - cf intake muffler does not change throttle response or engine performance but cuts noise in half!

Hi Pizza,

I'm going to be ordering that pipe from Ed very soon - does he sell the cf intake muffler too??

Rgds,
Mark

Yes, ed will be selling those cf intake mufflers

WOW a cheap option for pattern..... I'll take it...

since nobody in the world makes a very light aluminum header for zdz40re pattern plane applications, I made my own. it has the right amount of drop and thrust offset for my Impact. since I will be using the rubber wellnut engine mount system it will be neccessary to use flex tubbing or 2 soft breaks one near flange the other at pipe hookup to keep header from breaking from vibration. now I will find or make a very light aluminum flex tube or bend some 7/8" alum tubing to finish the header. if rc was easy girls would be doing it.

Someone was saying the Webra 1.60/1.45 header would bolt up to the ZDZ....I think.

http://www.topmodel.fr/product_detai...e70d8a&id=4113

http://www.topmodel.fr/pics/goods/170/170541_2.jpg

Hey Pizza,

I bolted a Webra MACS header to my ZDZ 40RE. All I did was increase the size of the current hole diamters of the header mounting flange and it was a perfect fit. Also, Karl Mueller, now has the dimensions and I believe, is considering making some ZDZ headers.

Thanks for the updates,
Jim W.

thanks for info, that one looks good, is it holding up to vibration?

I had this motor, and the Webra 1.45/1.60 rear exhaust header. Perfect fit, except for bolt holes on ZDZ are 5mm dia., if I recall. Plenty long, light, easy to 'tweak' as needed for thrust offsets.

Hi bob, was your zdz40 hardmounted, was your header flexible or solid? how many flights, did it break? thanks

I was the guy that bough Dick's "Petrel" with the ZDZ in it. Hardmounted, and at that time, the ignition module must not have been programmed to make it smoother, because mine shook like an out-of-balance Maytag!!! I kept it in that configuration for probably another 30-40 flights after I bought it from Dick before refitting it to a glow motor.

Bob- wasn't the shake typically at idle only?

The shake at idle was B-A-D. BUT - the resonance in the airframe at about 1/3rd throttle (I think it was around 3000rpm) is where the structure got beat up, and started breaking off control horns!

I understand the newest programming (via Jim W.) is VERY smooth....but he hasn't mounted it to a light airframe yet, just the test box.

My concern with the higher mass gas motors is the shock impulse to the extremely lightweight airframes we have to build to make that incredibly STUPID, RIDICULOUS, and MEANINGLESS 5 kg WEIGHT LIMIT!!!!

To do proper vibration damping on the ZDZ adds in a few more ounces, and when folks are pushing EVERYTHING, every GRAM to make that STUPID, RIDICULOUS, and MEANINGLESS 5 kg WEIGHT LIMIT, I think we're getting close to where the lines cross relative to durability of the airframe; I think we're not there yet.

Have had the same experience with the ZDZ.
http://www.rcuniverse.com/forum/m_20...tm.htm#2087347
Next spring I will try the Revolution 52. It has the same weight.

Not to distract the thread (sorry, Pizza), but Hans, have you considered, or run, the SM 30 from Modellmotoren ??