Aussie Roo

Thanks Kevin. A very revealing tale! And I hope kinda vindicates my hesitation at not immediately accepting the suggestion to move the CoG on the CARF Spit forward by 1/2 inch until someone who's actually flown one can give an explanation like you have. Thanks again and here's to many more happy landings with your Spitfire. Any chance you post a pic or three? Rupert

crashproof

Of Course my point is that the Spitfire more than any other GS Warbird i've had takes abit more experimentation within the recomended CG range based on the model, how it is built and who is flying it. I am sure like with other CARF's it will fly great as well. Kevin.

lazy eight

My Feedback: (389)

The guy I talked to at Toledo at Nick Zirolis boothhas one and has flown it many times and told me after moving the Cg around to get the plane to fly without having the elevator to sensitive said he moved it a 1/2 inch forward of where the instructions say to put it. I'm just telling you this because I would rather have it a bit nose heavy on the first few flights rather than trying to get it back on the ground with a snapy elevator. Just an FYI thats all. I wouldnt trust the COMP ARF manual for more than a guide at best its not the bible. There's no comparision between the two planes. I'm sure the gear isnt even in the same locations so I wouldnt try to compare the way they fly or taxi VS. CG. Each one is different. The Ziroli plane has a bigger tail surfaces then theComp ARF and thats just one differance. Brian from Dynamic Balsa is sending me new plastic to redue the cockpit. I'm doing it with no floor like the full size. I'll keep you posted on my progress.

Aussie Roo

I agree with you, slightly nose heavy at first. But what then of Crashproof's story of having to take 5 lbs of lead OUT of the nose to stop his Spit nosing over? May be I'll start 1/4" forward of where the manual says and just suck it and see.

lazy eight

My Feedback: (389)

I hope not to have 5 pounds of balist weight in the plane! But will see. As I keep adding more stuff aft of the CG point I'm starting to worry. I bought some Powered steel to use for my balist. I'm going to mix itinto epoxy then poor it into the cowl ring area. this will put the weight as fare forward as possable and hopfuly reduce the amount of weight needed overall. the spit and the ME 109 both have problems with the nose over thing. I hope comp arf moved the maingear enough to help with this problem. I'm going to movethe CG1/2" forward of the bookand try it there at first and let the flight testing tell the story. I can then remove or addsome removable weights to get it where it needs to be as per flight testing. I would like to have it in the air by the end of MAY will see. Thanks CRASHPROOF for your info and your spit looks vary nice.

smurfjet

My Feedback: (40)

Hey Guys,

I'll try and shed some light on the correct CG by finding out where I was on my Fiberclassics. I owned the older Fiberclassics Spitfire and flew it for some years. It's basically the same plane as the Comp Arf. The Fiberclassics skin was much thinner and more fragile but actually weighed more than the new construction Comp Arf. I have the Comp Arf but it's still in the box waiting for me to build it. My FC weighed in at 43 pounds. I flew it with a 3w-80 inline and then went to a quadra 100. I never had any issues with tipping it over on landing and thought the setup was perfect. I think the new Comp Arf spitfire will come in at least 5 pounds lighter unless it's really scaled out. When I get some time this next week, I'll try and dig up the FC manual and my notes to see where I had the CG at. I would assume it was right at 25 percent MAC as that is generally where I balance my planes at but I'll double check the number to be sure. It was a fantastic flyer and I'm looking forward to the Comp Arf build. I have an inline 104cc that I'm going to use. It is overkill but the sound of the inline is really nice.

Dave

Aussie Roo

Thanks Dave,

Are you going to use the Keleo scale exhaust in your new CARF version of the Spitty?

Rupert

lazy eight

My Feedback: (389)

Thanks Smurfjet for the info and the pic of your Spit looks nice. Did you have any cooling issues with the twin?? Do you have any more photos of the engine install? if so please share them with us. I got the new plastic for the cockpit yesterday and now on to the shop to transform it into a nice cockpit,

crashproof

Hey Guy's hope you all are well. Just a brief bit of inspiration for the reward at the end of the madness. Still watching, Kevin. http://www.youtube.com/watch?v=AI3dx4eAKfU

scooter

Hi, I just put on my wing on for the firsttime,and one of the long wing bolts is not long enough to reach the blind nut. Ithink thay all should 120mm long, as some of theblind are deeper in the wing saddle.I did note that the hole had no thread at the top of the hole like the other three,but Istill think the bolts shouldbe in the blind nuts and at least 1/16 sticking out at the bottom.

lazy eight

My Feedback: (389)

Well guys I have some bad news. I had to sell my Spitfire due to job loss. I sold it to my best friend and pro builder Watz Custom Aircraft. So once he gets going on it I will still follow along and post some pics as it get finished. It was hard to do but had to be done.

Aussie Roo

I'm sorry to hear that Lazy Eight, that must have been one tough call. I hope your fortunes change for the better real soon. is there any chance of a few photos of progress so far before you hand the Spitty over?

Best Wishes

Rupert

lazy eight

My Feedback: (389)

I droped it off today. sob. Will still have a chance to see it get done. Eric is a top notch builder and I live close by so I will be posting just as if I was duing the build. So stay tuned.!!

James Peters

hpais

Lazy Eight, sorry to hear what hapened to you. I have friends in the aerospace industry here in Brazil and they too are going through difficult times. It's one of the last industries to recover, but yet it's taking too long.

I have a question - whether the ZDZ 80cc R2 inline engine would fit the cowl? Troy has a pitts muffler that goes with it inverted. It's a bit $$$ at $1095, but at about the price if you consider a DA50 plus Keleo muffler. http://www.troybuiltmodels.com/items...R2-INLINE.html

What do you gentlemen, think?

Aussie Roo

Why are you so worried about a bit of an engine sticking out when you already plan to have a very un-scale pitts muffler hanging in the breeze? ;-)

hpais

Aussie, that's a very good point! Point taken.

Let me ask another way: would the ZDZ 100R2 online twin fit the cowl? I'm asking because I haven't received my plane yet, it will be a couple of months... But I may have to buy the engine before I get to see the fuselage - I have to bring it with me as luggage on my next US-bound trip.

Comparing the dimensions, the ZDZ is 250mm prop backplate to crankcase back, while the DA 85 is roughly 100 mm shorter, minus the 1.5" prop extension ~ 60 mm theoretical length difference. The DA 85 is about the same width, and spark plug height is equivalent.

If the "snout" on the nose can be cut, and the firewall could be installed 60 mm further back, then the ZDZ could be installed to fit.

Are my ASS-umptions in the ballpark?

All I'd have to do then is convince Keleo's Kevin to build a ZDZ 100R2 adapter, or use TBM's collector with KeLeo's kit.

Would it work?

Aussie Roo

Ouch! A few issues here.

If you can wait till tomorrow I'll post a couple of photos and measurements for you. Basically Yes, I think the 100 will fit. There will be a bit of work involved in moving the firewall back but so long as you do that well and reinforce it with some carbon fibre rovings or similar it should be OK. BUT (sorry) the Keleo exhaust is not going to work for a number of reasons. The exhaust stacks are mounted to the existing firewall, so not sure how you overcome that. Also with the firewall 100mm back your room inside the nose is going to be that much less. You need to cram as much as posible up front to get the CoG right and avoid 'dead' weight. The Keleo canister is quite heavy and Keleo's plans show it stradling the CoG. With the firewall 100mm back I think you might be struggling to keep it there. I'm actually making a few modifications so I can move the Keleo canister further FORWARD. I suppose you could still do it all but you'd have quite a bit of gear behind the CoG and would need a lot of lead up front.

If you are wanting a total scale look - that is, fully enclosed engine AND Keleo Scale exhaust, I think your options are 1) the DA 85 with a 3mm ply on front of the firewall and whatever thickness ply behind (I've used 3mm in front and 7mm behind the fibre glass firewall). You will need to cut a small hole to allow clearance around the plug cap but nothing will stick out so it will look scale in profile and, I would argure, the hole will be so small it won't be seen. Especially if you paint the plug cap the same colour as the nose underside.

There is another 80-85 engine with 2 spark plugs - at 45 degrees forward and back to the cylinder and threfore not so 'vertical'. I THINK this will fit inside the cowl but am not sure. Not sure of the engine make but I think it might be 3W.

Taygher is going this route so may be he can help us out with dimensions???

Other engine alternatives might be the DLE 55 or the new DA 60 perhaps. Not sure of their dimensions or power. Should be OK but for me, both are a tad marginal on power.

I hope this helps. I'll post more tomorrow about my set up (DA-85 and Keleo Scale Exhaust).

Back to flying the desk ... Tally ho!

Rupert

taygher

Hey fellow CARF Spitfire builders,

I will be using the 3W85xi in my plane together with the scale exhaust system from Keleo.
My engine has the same centered spark plug as the DA85 and since I haven't started my build yet I don't know if it will fit entirely inside the cowl or not.
I have tried to hold it in place inside the cowl and it looks OK but it's hard to really tell before everything is mounted correctly.

The engine Aussie Roo is talking about is the CS-version of the 3W85. (The one with the red/orange cylinder) The 3W85CS has two spark plugs mounted the way Aussie Roo said.
My CARF-rep has built the Spitfire with this engine and it fits inside the cowl. He uses a KS canister inside the fuse and the exhaust pipe comes out just beside the airscoop.


//Taygher

hpais

Looking at Mike Reeves website, on his 1/4 scale he used a Turnigy 80-100-A electric motor. Some videos on YouTube confirm the sound the motor makes with a nice propeller combination.

Given the apparent simplicity of the electric installation - no cooling issues (like twin engines, for instance), no damage to the cowling, no need for an expensive exhaust, I'm honestly thinking about going this route:

- Turnigy 80-100-A
- Carbon Fiber 24 x 10 propeller (2-blade) or 23 x 10 (3-blade) - the engine can take larger propellers, even a 23 x 10 4-blade...
- 2 x 6S 5000mAh packs
- 100Amp ESC from Turnigy


One thing I see already is the possible need to put a 2:1 reduction, because this motor doesn't have a bearing that takes the pulling force generated by the propeller correctly - should have a conical bearing for that, and that can be done on the reduction... or making a special mount like the guy on the video below made, not using the shaft but the spinning base.

There's a nice video someone posted with a 4-blade prop:

[youtube]http://www.youtube.com/watch?v=TUkKo4aW8OU[/youtube]

What would be the scale diameter for a 4-blade propeller for the CARF Spitfire? I can imagine a nice SOLO 4-blade scale-size bolted to this thing...

Any opinions, suggestions, criticism?

hpais

The video of Mick Reeves Spitfire which belongs to Peter Ford... listen to the sound it makes on the fly by...

[youtube]http://www.youtube.com/watch?v=WEA4euVXH10[/youtube]

vasek

My Feedback: (4)

I like the 4 blade prop[>:]

Aussie Roo

About 32 inches.

hpais

Holly long propeller Aussie!

Wouldn't you guess: that's the longest blade available from Solo prop!

The Turnigy motor has a 12 mm shaft... Tru-turn has an adapter for it. And maybe I can convince Solo to make me the adapter for this motor... Provided I get the conical bearing it needs...

David Bathe

Yeah... those epowered 1/4ers. BRILLIANT!

hpais

Still searching for data on the Turnigy 80-100 and found the Data Sheet buried inside the HobbyKing forum...

Also found the 4 bladed propeller on Zinger's website - http://www.zingerpropeller.com/4_bladed_propeller.htm

The data sheet says that a 32 x 12 propeller would fit the 80-100 motor, so if I deduce that the 3-blade would be 32-10 and the 4-blade 30-10, the 28-10 from Zinger would represent the top end of the propeller range usable by that motor... that would be equivalent to a 150cc gas engine! I guess an exaggeration of power for the Spitfire - better to use a smaller propeller to get more RPMs... and more pitch for more speed - 18" pitch @ 7000 rpm would yield approximately 120mph if the propeller were 100% efficient... - so the Zinger 24 x 18 4-blade would yield this sort of speed... I have to find a formula for how many watts to get this sort of RPM for this propeller - next post maybe...

For reference, the CARF Tucano on a turboprop uses a 3-blade 24x12

And the datasheets are attached.