Sethhunter

Thanks for the ideas guys. I put the biggest pulleys I could, almost full depth of the airfoil. I ordered some Kevlar. I've come to rust it on racing sailboats, but it needs to be inspected from time to time. I'm down to the wire on engine selection. Choice is either a Fuji 50 or DA 50. The Fuji has a longer crankcase, but I could put an extender on the DA (although they don't recommend it due to bearing load, but then, I don't plan any hi-gyroscopic loading maneuvers). The Fuji is about $200 cheaper. The DA has a rear carb so it would be a cleaner installation. The side carb on the Fuji would certainly be easier to access, but ugly. Both would need a pitts wrap around. Ugh. I don't need to spend the $ on a lightweight engine just to add more balast. I think I'm leaning towards the fuji as the operationally better choice.

TFF

Your plane is too nice to have something to stick out. I hope if the DA will fit competely in side you chose it. Maybe a big Satio or a Mokie. I think in the end you would rather say I'm glad nothing is sticking out rather than I spent to much.

Sethhunter

Thanks TFF - I think the only glow option with enough umph is a Moki 2.1. I don't think the big Super Tiger and Saito's have the power margin necessary. Tom P. commented his Moki 1.8 in a Pfalz had barely enough fuel at 24 oz to finish a competition routine. 32 oz of glow fuel per flight is a bit daunting on the wallet, but then they say, you got to pay to play!

CrateCruncher

My Feedback: (1)

Sethhunter,
I'm new to this thread and am quite impressed with your scratchbuild. Have you considered the DL-50? It's the same basic design and performance as the DA50 for less than half the price. I have this motor and am very happy! There's a big thread on it in the Gas Engine forum.

For those like me who lack the fortitude to design and construct one from thin air, rumor has it Glenn Torrence is planning to market a SERIOUS SCALE kit of the Pfalz DIIIa in 1/4 scale! Very cool!

ArdChoile

Hi Guys,

A friend of mine sent me this link - http://warbirdinformationexchange.or...=114334#114334
It has many photos of the recent Airshow in Omaka, New Zealand. I think you'll really like the couple of shots of the Pfalz.

Also here is another link - http://rnzaf.proboards43.com/index.c...6111240&page=5
also from New Zealand. Lots of WWII birds but also some really nice shots of the WWI aircraft now flying and on display.

I hope you enjoy them.

ArdChoile

Sethhunter

Hi Cratecruncher - yes I've read a bit about the DL50. I'm sure it is a good engine however I ended up buying the DA mainly on reputation, reliability, local expertise/parts, etc.
Ardcholie - TERRIFIC pictures. What a show that must have been. Thanks for posting the link.

Not much to post on the DIIIa; working on small details while waiting for the engine. I think the kevlar is going to work well for the aileron cables. Cockpit is coming along. Will post some pictures of the engine installation as I get into it.

AlphaWhisky

I guess this is the fullsize one in question. I photographed this, and dozens more interesting old planes at Omaka here in NZ at Easter just past.

In reply to Erich, I seem to recall commentthat the engine is an old DH variety as was used in the DH Rapide/Dominie series.

Alan W

arspievack

To bad that after going to all the trouble to build this reproduction he didn't spend more time getting it closer to scale.
It's a great project and could have come very close to the "real" thing.
Thanks for the photos... nice

ars

Erich_Prinz

Thanks for posting those pics Alan!

The only period photos of the aircraft I've seen show the exhaust on the right side (Mercedes is what one poster pointed out.) Just for my edification, what engine variants were used?

arspievack

Eric,
Off the top of my head I don't know. I'll try to look it up.
I'm going to bet that before I do Seth will tell you everyone. But I'll get to work on it
Thanks
alan

Mode One

My guess is only the Mercedes was used in production Pfalz DIII (a) aircraft. The reproduction would use what ever closest represented and was reliable. Not sure but I think the Pfalzs in the Peppard Blue Max used something other then Mecedes. This repo might be one of them?!?

arspievack

I'm pretty sure that only Mercedes had an in-line 6 which was used in the Pfalz, Albatross etc.
However throughout the war they were up-grading the engine to have more power, so that the later engines were different models (versions) of the M-B. I'm not sure whether they did it by increasing the displacment, which would have been the easiest way to do it. I'll try and find out.
alan

jtisch

I am 99.9% sure that that is Javier Arango's old Pfalz in Alpha Whiskeys photo. I heard that he had sold it. If so it is indeed a Pfalz from the "Blue Max" film. I think it has a Gypsy Queen engine in it, or did at some time.

J

TFF

I think the Blue Max planes had Ranger 6 cyl aircooled engines. I also understand that they did not fly well with the modern small prop and high rpm engine. They needed the big prop and lots of torque. What is interesting is there was a US licened version of the Mercedes engine in the 20's but I think it had a diffrent apllication than aircraft, but someone built a Folker DVII replica with one.

tom

Erich_Prinz

That's intriguing to me a slow/high torque combo makes the difference in flight characteristics. I'm presuming the undercamber - high lift/drag of the wing factors into the equation. One that Seth is likely thinking through right now!

The late Jef Raskin (the inventor of the Mac if you'll recall) was an avid model aviator with an astounding math background. He published an article on the scale flight speed (along with the formula) to get realistic flights of scale models.

It always 'felt' awkward to compare full scale WWI aircraft flying (the NY Aerodrome has clips of their demo flights) to our models in flight. Jef's explanation certainly shed new light on that awkwardness for me.

Thanks for the contribution here Tom! I'm soaking up just as much as I can here.

Erich

arspievack

Eric,
I don't if you were around or had any experience with the Wankle model engines that were put out in the 1970's. I still have 3 of them and loved them for their lack of vibration.
They were rated as a displacement of .30 cu.in. They were incredibly prop dependant. About all they would swing was a 10x4, thru 10x6 and you needed 16-18K of engine speed to get any pull out of them at all. High RPM or no torque at all.
I built a 1927 Stinson Tri-motor. 90 inch wing span. The Wankle(3 of them) fit nicely in the engine cowlings, and since they were hanging on struts under the wing,(2 were) lack of vibration was a nice addition to sound and performance. They looked great. The flight characteristics were terrible. vastly underpower. The 3 engines were screeming and the plane was struggling.
(And i was sweating) But it flew, barely. So I got tired of that, put fake propellors which would spin in the airstream, on fake engines in the outer pods (this almost killed me because it was so "un-scale") and put a very old supertigre .60 in the nose with a 12X6 prop. The plane was transformed. It flew like the real one , slow, sedate and graceful with more power at half throttle than I needed, and it sounded almost right as well.
I still have the Wankles they make great racing engines for small planes that you want to go fast and sound fast, but I've yet to find a scale plane that works with them. It's all about what torque you get at what rpm.
best regards
alan

Erich_Prinz

.
Well Alan, in the 1970s I was still dreaming of saving enough of my allowance money to buy an MRC 4 channel RC rig! The Hobie was the big deal then and it was WWI blue biplane on the cover of MAN that set my passion on fire for the hobby. Compounded by lack of funds, we lived in Greece where access to supplies was limited to APO or what the PX carried for the GIs. But I digress.

Do you think shaving a pound off the model (given today's hi-tech building materials) would have given those Wankels an easier time of it? (it's a loaded question, I know)

Erich

arspievack

Actually all up weight was just over 10 lbs. But I accept your comments, that we scale models pack on "scale" weight and then blame everything (including poor flight characteristics)on something else.
Nonetheless I thought that 3 - .03 cu.in engines should be the equavalent of one .90 cu. in engine and those 3 engines weren't.
My guess is that if I had put 3- .25 convential engines in the plane it would have worked great. But I wanted the rotary engines, the size and the look. I got all that but no pulling power becasue I couldn't swing the right size props.
I'll try to load up some pictures but I know someone will complain about putting 1927 Stinson pictures on this Pflaz thread.

alan

jtisch

The source I have says they had Gypsy Major engines (I don't know the horsepower rating) when built for the film. Gypsy Queen is 200hp(IIRC) and was installed after being acquired by Javier.

J

Erich_Prinz

Agreed, it's a little 'off topic' yet relevent to scale interests - so maybe okay.

With the comments in the prior post, I was sorta hoping to peak your interest in building another Stinson with all the updated materials and put those Wankels in the new project. With my schedule, I can only hope to enjoy the hobby vicariously; so please don't take the post in any other way.

Sneak some photos in before we get caught!

Erich

arspievack

Eric,
Don't worry I understand we modelers, we make friendly jabs at each other all the time. No offense taken.
I'm not likely to build another but will try to sneak the photos on our thread.
best
alan

TFF

One of the best books to read is Flying the Old Planes by Frank Tallman. He realy describes the diffrences on how the planes fly, and he is so enthusiastic about every thing that flys. He goes into how the reproductions dont do as well with the small props and how the planes just dont handle right. I guess he single handed saved a large chunk of WW1 planes because he had a Camel,Spad VII, SE5a,Nieuport28, Pfalz DXII, and FokkerDVII not including his repos. I hear he was a fan of modelers too.

The Gypsy engines are right for the reops and makes sense where they were made and what would have been avalable.

Alan, you and your Stinson was pictured in some fuel ad if I remember?

Tom

arspievack

Tom,
You're right but I don't remember the fuel. That was a long time ago.
Frank Tallman was a hero of mine. Don't know if he's still alive but for decades he was Hollywood's main stunt flyer.
I saw him in shows and he could make planes do things they weren't supposed to do. I'd love to know how many hours he had in the air. But anything he said about flight, props, etc. I'd believe
ars

TFF

Unluckly Frank Tallman has been gone for a long time. What is also is amazing about him was all the flying he did in the public eye was with one leg. He lost the one to an infection when he recked his son's gokart. He earned all his Navy qualifications back. How many do you think could test fly a Sopwith Camel with a prosthetic leg never being in one before? He seemed to be as excited as a kid everytime he got into a plane; that made the book fun to read.

Tom

ArdChoile

Gentlemen, heres a little bit of info on the two Blue Max aircraft in New Zealand.

The first D.III built by Doug Bianchi's Personal Plane Services Ltd in England, featured a steel tube Tiger Moth Fuselage with added coaming to match the Pfalz profile. It was powered by a 145hp Gipsy Moth 10-2, 4cyl, air cooled engine from a chipmunk, modified to run upright. (Dummy cyls and Exhausts added to give the look of 6cyls)

The second D.III built by Viv Bellamy's Hampshire Aeroplane Club Ltd, was built to drawings by Ray Hillborne, which was said to be very accurate drawings. But the fuselage wasn't done using the "Wicklerumpf" method. As far as I know it is also powered by a modified Gipsy Moth engine.

Both are now owned by Film Director Peter Jackson.

Hope this answers a few of the questions.

ArdChoile