yeahbaby

My Feedback: (21)

Mark

thanks for posting progress of your A4 conversion.

I've been contemplating the conversion of my OS .91 version for some time now. Your success with the Wren 44 has inspired me to renew my turbine fund for next year. I went out to the garage tonight and ripped out my DF engine.

hopefully Santa's Lil Helper will put in a good word for me with Jolly Saint Nick.

congrats again

cheers

Dr Honda

My Feedback: (4)

Nope... didn't get any vids of the maiden. I wish I would have... it flew very well. All I have is pics of it sitting around... but here it is. (I'll get a flying vid next time out)












I have 2 small kids (6 years, and 18 mo) So the "Fat Man" funds normally have to go to them. But who knows... maybe I can convince him to bring me some new toys too. If Jet Munt gets their M-35 done... I will have to beg. I'm really liking these small engines... but a p-20 is too small, and the Kolibri's are TOO expensive. (in the USA)

Mark 5

Yeahbaby, you will love this combination! It is lighter than the OS91 Dynamax,more powerfull,more dependable and sounds great Mark

yeahbaby

My Feedback: (21)

I'm glad to hear the 44 performs well.. I flew my previous one with a P60 and it flew great but the AUW was just a bit much for the gear structure. I've been pawing the ground ever since to do it with the 44.

congrats again.

Bob_B

My Feedback: (11)

Buck crack that wallet open and buy that motor!

yeahbaby

My Feedback: (21)

hahaha I'm hoping I can sweet talk Mrs Claus first.

Mark 5

Art, how is the A-4 comming along?

Art ARRO

My Feedback: (5)

Mark,
It's coming, but currently at the end of the line for my winter projects. Just last night I found a set of A-4 inlets that BVM made for me. These will advance the project as the original inlets were shaped from balsa sheeting. It took several attempts to find the right balsa andcurve it to and nice inlet. without splitting.

What tailpipe are you running in yours? I was planning on Wren to make up one of their boosted tailpipes, but with a double wall. What's the length of your tailpipe-approx)? Thanks.

Art ARRO

Mark 5

Art, my pipe is double walled and is 24" long. It keeps the fuselage very cool. My friend Tino from M.D. built it. It does not have any thrust loss, however if you can get 1/2 pound more thrust with the wren pipe I would recommend it. With small jets 1/4 or 1/2 pound thrust make a noticable diffrence.

Art ARRO

My Feedback: (5)

Mark,
Thanks for the length of your tailpipe for the Yellow A-4. I did a quick measurement of that length on the hulk of my old BVMA-4 and it looks about right. The turbine nozzle would be about an inch forward of this and it puts the mounts right about where the Turbax sat. I'll speak with Ron B. on getting an augmented pipe made up for the 44.
Also, what is your tank setup? I figure I can use 2 Sullivan DF-11's in a saddle position with a SS-16 up front in the crotch of the inlets. Let me know on this. Thanks in advance.

Art ARRO

Mark 5

Art, look at the first page of this post, you will see a few pictures of my tank setup. I have two 10 oz tanks on the floor and two 8 oz tanks on either side of the turbine.

Art ARRO

My Feedback: (5)

Mark,
I did go back to your early post and noted the tank setup. I like the idea of the tanks clustered about the CG. My old DF version just hada SS-16 installed in the crotch of the inlets which resulted in a nose heavy takeoff and gradual shift to the rearafter fuel burn for landing. I have enough of the hulk to make some fit measurements with DF-11 saddle tanks, and perhaps a 16 oz vee-shaped boat tank beneath the 44K, all centeredabout the CG. Mine will be a one-peice jet to save weight.

Art ARRO

Mark 5

Shaun, I remember that you had a Skyhawk with a p-70 or a p-80. How did it preforme? What did it weigh? How did the landing gears hold up? Where did you locate all the fuel?

Shaun Evans

Hi,

I shoehorned a P-80 in one a while back. I carried 12 ounces in a header inside, and 47 ounces in a centerline tank. I could get 5 minutes with that since I wasn't drawing much at the throttle setting I had. Gear held up fine until I wrecked it!

Mark 5

Hi,Shaun, what did tha a-4 weigh and how did it fly with all that weight? It must have been a rocket with the p-80. Was it difficult to slow it down for landing?

Mark 5

Art, you must be very close to finishing your A-4. Let us know about your progress. Mark

Art ARRO

My Feedback: (5)

Mark,
The A-4 Skyhawk is next in line for building, right after I complete mymodded Alfa MiG. Note thatthis A-4 is from a very early BVM semi-kit, meaning it's halfway between a scratch/plans build and a normal kit. Only the fuselage and wheel pods are molded fibreglassand all parts must be hand cut from sticky-back mylar templates. The formers are composite; balsa laminated to 64th ply on both sides. The wings and tail feathers are built-up rib/spar constructionwith balsa sheeting. A lot of work involved just tofabricate the basic peices.
Note that ARF wasn't even a word back in the late 70s. Remember "Hot Stuff", as the revolutionary new adhesive? Anyway, I've ordered the long lead time items and an augmented tailpipe is currently being made in the UK. I figure it will be a mid-to-late season maiden on this A-4.
I'm also trying to keep it very light asmy previous glow DF A-4 weighed less than 9 lbs-dry, even after a major rebuild due to a crash in a tree. Will keep you posted on this.

Art ARRO

Mark 5

Another 5 flights today. I moved the CG back 1/4 inch and increased the elevator , aileron throws a little. I can now do an outside loop and I am able to slow down the A-4 for landing. I tried a few down wind full throttle passes and am surprised at how fast the Wren 44 gold pushes the A-4. The verticle is also good, all from a turbine the size of a Coke can.

yeahbaby

My Feedback: (21)

so where is the CG now and measured from ???? I forget leading edge or trailing edge? I am looking at my little bird patiently waiting for a W44.

can't wait

Mark 5

Hi Yeahbaby, The CG is 12 1/4 incher measured ftom the trailing edge of the wing. This helped to slow it down for landing , however I think it flew a little bit better with the CG at 121/2 inches from the trailing edge of the wing. This is one airplane that you do not want to fly tail heavey. It will snap at every opportunity.

Mark 5

Yeahbaby, are you purchaseing a new Wren 44gold? Kingtech has a very small and light new turbine(K60) worth considering.

yeahbaby

My Feedback: (21)

I'm thinking about it. I haven't done the comparison yet between engine weights but I can only assume the Wren 44 is the lightest among motors in it's class. I met Barry in Mississippi a few weeks ago and know that he backs a great product.

will look into the two motors a bit more when it comes time to choose.

congrats on a great looking and flying bird.

cheers

Mark 5

Art, how did you get your previous A-4 under 9LBS ? Were the wings glassed?

Mark 5

Hi Art,it's been a few years since you started the A-4 project.Did you get a chance to fly it?

Art ARRO

My Feedback: (5)

Mark,
Life has gotten in the path of finishing this A-4/Wren 44 project but it is still pending. Currently, working on a Mirage EDF project and a Hot Spot to complete before the A-4.
Note that my original A-4 was from BVM with a built-up wing and tail construction along with a very light layup of the glass fuselage. The model was glass covered, 3/4 oz cloth, and painted with K&B Superpoxy. The AUW of under 9 lbs was after 2 repair efforts including a total paint scheme change- from Blue Angel to Adversary. It flew for over 15 years in 9 states and 3 AMA Nats before demise at a US Scale Masters Qualifier.
Rgds,
Art