Here we go again..Warbirdkits.com 150% Cutlass Twin 70mm/90mm single - RC Groups
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Apr 09, 2010, 06:41 PM
Big gov never Works
St. Martin's Avatar
Cool

Here we go again..Warbirdkits.com 150% Cutlass Twin 70mm/90mm single


another Cutlass.. As alway's, Tom @ Warbirdkits.com, grants me a wish, for doing the work on his kit's. This is the third time he enlarged a design for me. Thanx Tom! We kept getting requests, on the Cutlass threads, for a 90mm size. This seems to be a popular size. So..Tom say's he will kit it if there is interest. My first request came from club member Ken LaPoint two yrs ago, when first flying the proto. Most of his are minimum 90mm. I kept this in mind.

So..I'll make up the ducting for a single 90mm and twin 70mm. Twin will have glass intakes. The 90mm will use the same built-up intakes as the smaller version.(But, if there is enough interest, I'll make molds for 90mm glass versions. So speak now or forever hold your peace.) Roger(Air Sally) agreed to accept any lay-up work I can send him. There is no better a lay-up person around. Ducting pricing is up to Roger and purchased directly through him.

The reason for making my version a twin 70mm is..I"M A MASOCHIST! Seriously, I'm not set up for 90mm yet. Still a smaller EDF person.

At 150% WS comes in at 46.125". LOA 42.125". Have no idea of the WA yet or projected weight. I asked Tom to cut the kit entirely from balsa. No ply. I'm going to substitute composite glass and wood with 1/64 ply in these areas, where ply would be. This should keep it light. If kitted, these parts could be made from ply. But, I like the added work for a lighter frame.

The power system will be (2) WM 400 MkII's, (2) ARC 28-47-1.5, (2) 60A Turnigy(plush) ESC's, (2) Zippy Lite Max 3000-5s 40c packs. Individual testings gave 54A@ 1035W. 2070W combined. This was with no intake lip or ducting but with the supplied exaust duct. The fans are very loud at around 300W power. Sound real nice at power above 50%. So I'm going to see if I can "soft mount" the fans to reduce the low power noise. I have a few ideas.

I started this afternoon around 4pm. Wing skins are always done first. Then the nose section. Will laminate the bulkheads and make up twin fan mounts. Then make a larger fuselage jig.

Fuzz
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Apr 09, 2010, 08:36 PM
EDF Jet Jam 2017, June 15-18
Kevin Cox's Avatar
I thought I had a problem with my F/A-18 Hornet addiction but man you have some issues too .
Want my therapist number? I'm not cured I just have other people thinking I am

Seriously, this really going to be another interesting build with the size and power fans you can't go wrong. I'm going to guess a RTF weight of about 4.5 to 5lbs...gonna be nice
Apr 09, 2010, 08:48 PM
Build'em and Crash'em
Ken Lapointe's Avatar
He is really just enlarging pictures of previous builds to make it look like he is building a larger plane.

We are definitely going to need a group photo of all of them together though.

Oh and Kevin, no one thinks you are cured, we just know a lost cause when we see one.

Off to a nice start Steve. Hope the field is ready by the time your plane is.
Apr 09, 2010, 08:59 PM
deltas are cool
AIR SALLY's Avatar
yes i'll help where i can looks like a nice size .

regards Rodger
Apr 09, 2010, 09:57 PM
Some epoxy & it flies again...
Low Pass's Avatar
Wow, cool project.
Next one should be a twin 90
Have to watch this.
Apr 10, 2010, 12:13 AM
Big gov never Works
St. Martin's Avatar
Well Kevin, I may get the chance, with the F-18. I've been messing with the plans you sent, a few yrs ago. Distinct possibility for two micro's. So have that ph# ready. That seems about the normal weight for twin 70mm stuff. I would like to see it just under 4#.

Your right Ken, about the field. Look who's talkn', "Panther Boy"...lol How many of those? 10?

Thanx again, Roger. This would compliment your "Ford". I'm sure Brent could stuff 3Kw into one.

I was thinking the same thing LP. Go to the caption, first pic.. https://www.rcgroups.com/forums/show...8&postcount=81

Charging the batts on my cam. I'll post more progress tomorrow.

Fuzz
Apr 10, 2010, 12:51 AM
EDF rules... :)
AirX's Avatar
Hi Steve,

I am up for the 90mm verison. What do think, the prototype will take you about a week and then we are a go for purchasing...

Cheers,
Eric B.
Apr 10, 2010, 07:28 AM
Big gov never Works
St. Martin's Avatar
Ha..ha..ha.. I wish, Eric! Your opinion. Low cost built-up intakes, or fancy glass versions? No diff in performance, just cost and a few hrs added work for the builder. Because of the single fan location, it's a strait shot to the fan. The twin is a curved affair, like the micro twin Cutlass. So glass duct required there.

Fuzz
Apr 10, 2010, 08:24 AM
Build'em and Crash'em
Ken Lapointe's Avatar
Not 10, the Cougar is not a Panther
Apr 10, 2010, 05:23 PM
EDF rules... :)
AirX's Avatar
Quote:
Originally Posted by St. Martin
Ha..ha..ha.. I wish, Eric! Your opinion. Low cost built-up intakes, or fancy glass versions? No diff in performance, just cost and a few hrs added work for the builder. Because of the single fan location, it's a strait shot to the fan. The twin is a curved affair, like the micro twin Cutlass. So glass duct required there.

Fuzz
Built up intakes are good for me.
Just make sure there is room for 8s 5000mah batts. I have two fans at the moment, a Wemotec Midifan Pro, Nue 1415 1.5y good for ~2.5Kw and a Himax 100mm with the Himax motor that come with it which is good for 1300watts on 6s 5000mah. What do yhou think would be the call for this one?

Eric B.
Apr 10, 2010, 05:42 PM
Big gov never Works
St. Martin's Avatar
Quote:
Originally Posted by Ken Lapointe
Not 10, the Cougar is not a Panther
My error

Progress is going to slow quite a bit, now. I have to temp mount the Midifan and make up the intake parts. Neat thing is there will be one set of intakes available. I'll donate these to Eric, seeing he was the first to put a claim on a kit, should we get enough response, and for being a long time friend. Then I can go through the motions of mounting the WM 400's, duct molds.

Partial strip planking will be done on the aft fuse to stiffen things up a bit.

Fuzz
Apr 10, 2010, 05:49 PM
Big gov never Works
St. Martin's Avatar
I think the 6s will be the limit, Eric. And you will get this set of ducts, for the midi. This design has problems with CG and nose heaviness. You will most likely need to move the packs through F5 to between the intakes. First proto required this. I suspect this one may, also. But one never knows. So I'm going to plan for it anyway.

The 5s2p 3000 packs are more than enough room stacked with a separation.

Maybe one of the ARC mtrs will work good on 6s in the Midi. Be nice and light, and this jet does not need extreme power to move out well.

Fuzz
Last edited by St. Martin; Apr 11, 2010 at 03:52 PM.
Apr 10, 2010, 06:46 PM
EDF rules... :)
AirX's Avatar
Cool, the lower powered setup needs a home too...

Always like the Cutlass and the 90mm version is where I am going lately, easier to see the larger planes when flying.

Eric B.
Apr 10, 2010, 07:07 PM
Big gov never Works
St. Martin's Avatar
I'll be sending the canopy mold off to Sparky, when done. He already said he would pull me a few. Then send the mold to Tom. I think Tom would do well to go with this size. There seems to be a higher interest in this sized EDF, Eric. As Smooth as the smaller one flew, I know this one will be far better and more realistic. I think you'll find it to be the best EDF you ever flew.
After these two, I'll take a break from building Cutlasses for a while...

Fuzz
Apr 11, 2010, 02:32 PM
Big gov never Works
St. Martin's Avatar
Progress from the morning: That old Midi rotor came in handy, Ken! Because the mounts were sized for a minifan, at original size, The midi compares to the 505 66mm fan as far as clearance goes. This allowed the fan to be moved aft behind the fan mount bulkhead F7. Very similar position, proportionately. Still a lot of room for "stuff" behind the fan. A good location for a Rx pack for balance, if necc.

So easy to work on a plane in this scale. Eric, I'll send the fan mounts with the ducts. I won't need them.

Fuzz


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