RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   RC Warbirds and Warplanes (https://www.rcuniverse.com/forum/rc-warbirds-warplanes-200/)
-   -   Spitfire arf 95" phoenix assembly (https://www.rcuniverse.com/forum/rc-warbirds-warplanes-200/11641960-spitfire-arf-95-phoenix-assembly.html)

Lifer 10-16-2017 11:54 AM

Video?

Flyfast1 10-16-2017 02:32 PM


Originally Posted by Shaun Evans (Post 12375806)
Nice work, Sir.

Got to fly mine this weekend. She flies GREAT! Nice, slow landings but pretty sluggish on a 55RA. The cowl definitely needs venting. The P-51 spinner looks fine on it, btw. The retracts held air for a week and worked great.

Shaun,

Nice to hear. Which spinner are you using?

-Ed B.

Shaun Evans 10-16-2017 04:19 PM

Hi,

I'm using the Dave Brown P-51 or 'parabolic' spinner.

Hot Rod Todd 10-17-2017 04:44 AM

Shaun, did you try the stock spinner to see if it spun up ok, or were you afraid to use it because of the little screws holding it together?

I would imagine you used the 6" diameter spinner. It matched up to the cowl well?

Shaun Evans 10-17-2017 05:55 AM

Spinner
 
Todd,

No I tried it. Got about half throttle before the end of the cone was doing about an inch of run-out and trying to shake the plane to pieces. It was scary. The DB 6" fits the cowl perfectly.

Hot Rod Todd 10-17-2017 07:11 AM

2 Attachment(s)
I was afraid of that. Even if it holds up for a while, all it takes is one time in flight to go out of balance and it could be all over. Spinner breaks prop, out of balance prop breaks engine out of the nose, plane comes down. I just wish there was a better spinner option. The Mk XIV Spitfire has a very long spinner that's quite distinctive. As an example, the stock spinner is 7" long, the Dave Brown is less than 6" (based on dimensions I've seen). The Spitfire spinner is a bit more pointy than the P-51 style as shown in the comparison photo.

If anyone has a line on a more scale option for a spinner, please post.

Hot Rod Todd 10-18-2017 07:12 AM

2 Attachment(s)
Mick Reeves over in Britain has a 6" Spinner made for his 1/4 scale Spitfire. With shipping to the US it's about $100. Dave Brown Mustang spinner would be cheaper, but I think I'll take a chance and check out the one from Mick Reeves that appears to have a better profile for the Mk.XIV..

I'll post some photos and let you know how it works out when I get it.

Shaun Evans 10-18-2017 09:12 AM

Hi

Is this a polyester or epoxy cowl?

OldScaleGuy 10-19-2017 03:00 AM

How is the spinner to cowl fit on this Spitfire? I have had two Phoenix planes and in both cases it appeared they added thrust to the engine mounting but did not account for the offsets in the cowl plug/mold. Therefore, i could not get a nice consistent fit between the cowl and spinner.

Shaun Evans 10-19-2017 03:03 AM

Hi,

So I had a little stroke of luck the other day! Went to the flying field to maiden this bird, and had two very nice flights, including one with my 12-year-old son on the cord. With the cowl on, the engine temps (at least according to telemetry) were 100 degrees hotter than the hottest run-up on the ground without the cowl. I was getting up to 355 in the air, which I think is too hot for the DLE 55RA.

The 'luck' part was that a week-long 3-D event had just closed down at the field and none other than Colton Clark was there. He and several others of the best RC pilots in the US were clapping for my maiden landing, so I went over and asked them about engine temps. Colton went over to my plane, got down on the ground and drew out his suggestions for cooling mods onto the cowl with a sharpie. I followed his suggestions exactly and now I'm getting temps that are only 20-25 degrees higher than without the cowl. Gotta love it when the champs and real pros 'give back.'

:)

Shaun Evans 10-19-2017 03:04 AM


Originally Posted by OldScaleGuy (Post 12376465)
How is the spinner to cowl fit on this Spitfire? I have had two Phoenix planes and in both cases it appeared they added thrust to the engine mounting but did not account for the offsets in the cowl plug/mold. Therefore, i could not get a nice consistent fit between the cowl and spinner.


Hi,

It's pretty good, actually.

OldScaleGuy 10-19-2017 03:07 AM

That is good to know. Thank you!

SWORDSN 10-19-2017 04:31 AM


Originally Posted by Shaun Evans (Post 12376467)
Hi,

So I had a little stroke of luck the other day! Went to the flying field to maiden this bird, and had two very nice flights, including one with my 12-year-old son on the cord. With the cowl on, the engine temps (at least according to telemetry) were 100 degrees hotter than the hottest run-up on the ground without the cowl. I was getting up to 355 in the air, which I think is too hot for the DLE 55RA.

The 'luck' part was that a week-long 3-D event had just closed down at the field and none other than Colton Clark was there. He and several others of the best RC pilots in the US were clapping for my maiden landing, so I went over and asked them about engine temps. Colton went over to my plane, got down on the ground and drew out his suggestions for cooling mods onto the cowl with a sharpie. I followed his suggestions exactly and now I'm getting temps that are only 20-25 degrees higher than without the cowl. Gotta love it when the champs and real pros 'give back.'

:)

Please outline his suggestions,it would apply to any narrow cowl installation.Thanks

Hot Rod Todd 10-19-2017 04:39 AM

The were thinking ahead and made an opening in the firewall that allows cooling air to pass, trouble is if you leave the scoop as is on the bottom there's no place for the air to get out. I plan on cutting air outlets in the back of the scoop to help the cause. Also, many tend to cut the exhaust outlet holes as tight as they can. Making them larger is another path for the air to get out.. For inlet I'm sure it would help to cut out some in front of the cylinder, that way you're exposing more of the cooling fins. The DLE-55RA has larger cooling fins than the DLE-61, so it will be even harder to keep the 61 cool. That tightly trimmed cowl never looks good after a poor engine out landing due to overheating.

radfordc 10-19-2017 01:28 PM


Originally Posted by Shaun Evans (Post 12376467)
Colton went over to my plane, got down on the ground and drew out his suggestions for cooling mods onto the cowl with a sharpie. I followed his suggestions exactly and now I'm getting temps that are only 20-25 degrees higher than without the cowl. Gotta love it when the champs and real pros 'give back.'

:)

And now you're going to share with us?

Shaun Evans 10-19-2017 03:02 PM

8 Attachment(s)
Hi,

It's all pretty much standard stuff, but what was cool was that a guy as talented as Colton was eyeing my particular setup and giving me a 'custom' recommendation. He drew the little 'smiley-face' opening under the spinner. He suggested I close off the opening in the scoop and instead open up a teardrop-shaped hole behind the scoop opening AND build some sort of ramp at the leading edge of that hole. He suggested that instead of finding some kind of triangle stock, I could just heat up and bend the glass itself. That's what I did after cutting two slots which made a 'flap' of glass in front of the hole. The ramp creates low pressure and sucks out the hot air. The smiley-face inlet lets the cool air in and onto more of the engine than just the top of the fins that stick out of the cowl.

toothepick 10-19-2017 04:54 PM

Hot Rod Todd,
I have the 6" spinner from Mick Reeves. The profile is just ok, but the backplate is only 1/8 thick. I would not put this spinner on a plane with the backplate that comes with it.
I was planning to have a local machine shop mill a new backplate to fit the spinner.
Ziroli has a nice 6" P-51 spinner with a machined backplate that is more stout than the Reeves.
Precision Cut Kits list a 6" spinner for their Don Smith 1/4 Spitfire but I have not seen it or know who makes it.
Hope this helps.
Tim

Shaun Evans 10-22-2017 06:42 AM

Added pics (thanks, Todd!)

Shaun Evans 10-22-2017 08:22 AM


radfordc 10-22-2017 10:19 AM

Looks like the DLE-55RA does a good enough job. I was debating on getting a DLE-61 but will go ahead with the 55RA I have and see if that suits me. Nice flying.

OldScaleGuy 10-22-2017 10:34 AM

Not to change the subject but i can't imagine that the 61 has that much more power than a 55RA. My 55RA is a power house.

Hot Rod Todd 10-25-2017 04:56 AM

6 Attachment(s)
I went with the 61, hoping that it can pull a 23" prop that will pull the big Spitfire around a bit better. Besides a bit more displacement the 61 has a 10.5:1 compression ratio compared to 7.6:1 for the 55RA (If you believe the specs).

Got my Best Pilots Sailor Malan pilot in the mail. At 1:5 scale he's a bit small, but the cockpit is quite shallow compared to the real thing. The fit looks decent, and his body fits well sitting on the shallow floor. I was also able to coax the instrument panel out. It's glued in with silicone, so it takes some patience and work to get it out. Since I'm scaling this thing out, I might as well put some extra time in the cockpit. Here are a couple photos showing Sailor during some fitting tests.

Shaun Evans 10-25-2017 04:49 PM

Hi Guys,

So I had a couple of prop-strikes the other day when one of my mains collapsed (which they'll do even at 80 psi, apparently). I was using Xoar wood. How likely is it that my shaft is bent? What's the best way to check?

radfordc 10-25-2017 07:06 PM

If prop strikes caused bent cranks in DLE engines I would likely know. I should buy stock in a propeller company I've broken so many. The joke in my club is "there's another $20 landing!" And, no I've never seen any evidence of a problem with the engine.

Now the old Zenoah G-38...you could look at it wrong and the crank would bend.

SWORDSN 10-26-2017 04:57 AM

If the strike was on grass you are probably OK. You should be able to see wobble at low to med throttle setting.


All times are GMT -8. The time now is 01:48 PM.


Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.