By the way, I didn't have any spare 2409-18 motors laying around but he's trading me one for an old radio he wants to give to a friend, so it looks like she's getting this monster torque motor. This is good, since I was thinking of using a re-wound 2408-21 in her, but would much rather have the overkill/tons of torque/low rpm/and mild amp draw of the 2409-18. That motor will be swing something between or at a 8x4 to 10x5 APC E. Even on a 10x5E I think the amps are only like 10 to 14 or so. I was planning on using a 20C 3 cell 2200ma pack in the plane but just realized I should be able to run my 2000ma 10C 3 cells as well, which is good because I don't have any plane built right now that can use those. Will have to re-read up on the 18T to make sure my memory on amp draw is right, though.

critterhunter,

where did you get your wings, or did you make them?

Tom

I'm sure you have thought of it already but based on my recent experience with ESC's inside fuselages (they can get hot - fast! 'specially if you are really pulling some amps through them) - make sure you arrange to get some cooling airflow over the ESC !

Good luck,

Nigel

Made the wings. I always melt channels and chambers and mount my electronics onto the side of the fuse, just deep enough to be flush and hide with tape. Also like to add an extra heat sink to the top of the stock ones for more cooling, and make sure there is some kind of vent to flow air past it. I'll be using a 30 amp ESC with the 2409-18 motor. On a 10x5 APC E and 3 cell 2000ma+ pack the amp draw will only be about 12 to 14.5 or so. I really like these 18T motors for low RPM/high torque. On that prop it'll put out about 30 ounces of thrust.

By the way, have to check my measurements on the verticle stab/rudder. Looks too small to me. This will also be my first aileron/elevator/ & rudder setup. I've always used one or the other but not both.

Hi critterhunter,
it sounds like you are getting it all sorted out.
I'm not sure why your tail end has come out a little small. Did you use the posted plans?

Peter

Well,

Finally got the old ESC out (CC Phoenix 25 brushless) - the factory installed heat shrink had actually melted !!!!!!!!

Put a Thunderbird 18 ESC in and fitted an APC SF 10x 3.8 then (very, very, very cautiously LOL) started to test the engine....propless at first - it ran correctly & no heating on the engine or the ESC....put the prop on and ran gently for 10 seconds, etc, etc. Finally WOT with my Hyperion in the circuit. The figures I got were:

10.95 v
10.58 Amps (seems a lot - way more than the Komodo data sheet for that prop - 11T motor ?)
115 W
6,480 rpm

Kept checking the ESC and motor for excess heat - all cool - so, with any luck I'll be in the air again on Thursday (can only fly at weekends 'cos during the week it's dark by the time I get home)

Nigel

I have been thinking of offering short kits for the full fuselage SE5A (and my SU26-MX).

The kits would be basically all the Depron foam parts cut (Currently I use templates and a hot wire cutter).

The material cost is around $25 USD (1.5 sheets) and it takes approx 3 hours to cut out a kit. Shipping from Australia would also need to be included. Payment would be via Paypal

I'd be interested to hear if there would be any interest and some feedback on how much to charge.

I found Rob Badcock's site: today, so I stuck my numbers into his calculator:

Power in: 115W (so 83W per pound !)
Power out 78W
Thrust - 693.1g / 24.45oz.
Eff: 67.3%

Since my AUW is 627g / 22.12 oz I have a thrust to weight ratio of 1.1 to 1

Nigel

Did a little more work on the SE5a. I mounted the 2409-18 motor via an aluminum "U" shaped strip it's screwed to and the aluminum is held around the front of the fuse via gorilla glue. Also cut off the nose (cowl) and holled that out to hide the motor. When doing cowl work like this I just heat up a socket that is roughly the diameter of the motor's bell and melt out a nice clean hole behind it. Also melted out a wider shaft hole so the motor gets plenty of air. An exit hole is located on the bottom.

Originally Posted by pmjass

Hi critterhunter,
it sounds like you are getting it all sorted out.
I'm not sure why your tail end has come out a little small. Did you use the posted plans?

Peter

If you mean the tail boom it's to scale length. The front of the fuse is longer. If you mean the vertical stab/rudder, yea...I think I measured wrong and have to re-check that. Also going to re-check the match on the tail wing.

Critterhunter

I was a little worried that you were using the plans that were posted in this build thread and that there might have been an error with them.

I wonder what thrust to weight a full size SE5A had. Probably not quite his much.

Originally Posted by Nigelp

Since my AUW is 627g / 22.12 oz I have a thrust to weight ratio of 1.1 to 1

Nigel

I've got the parts cut out, the fuse partially assembled, and the control surfaces hindged.

Before I mount the motor, can somebody tell me if putting it in the scale position, below the center line, adversely affects the 3D flying capabilities?

Originally Posted by pmjass

Critterhunter

I was a little worried that you were using the plans that were posted in this build thread and that there might have been an error with them.

I'm sure there is no error in the plans. I'm a bit lost here, since there are two SE5a threads going on right now in this forum. The plans I found (and they were the only free plans I could find anywhere on the net) were in one of these two threads, and also features a single page top/side view of the plane, a color (brown) top/side view of it (also on a single page), and then the tiled prints for building one out of flat foam. Since my build is larger, I didn't bother with the tiled prints but rather just measured the single page outline print and then X that by 7.2. IE: Wing on that page was 5"x7.2=My 36" wing. Like I said, some of my conversions are best guess since I don't know how to convert anything but .25, .5, .75, etc. Does anybody have a formula they can show me on inches to decimal and then back again conversions? I'm sure most everything is exact or at least very close. While I was trying for scale this isn't a hard and fast rule, as I wanted the nose a bit longer to make COG easier to achieve and, as said, the wings I'm using are Clark-Ys that are almost 7" wide.

Here's the thread I got the single page outline print from that I used as my guide to measure and upsize. Hmmm....the other single page color print isn't on there that I can find. Where did I get that? Thought it was with it too? Maybe it's in this thread....Looking...

I'm planning to blow up the single page color print and spray glue it right to the body so no painting is needed. I did this with a homemade Mustang and love the look/feel/strength of spray gluing paper to foam. It also makes hiding repairs easy enough....Just spray glue on a new print over the damage repair. Really helps to strengthen foam too.

http://www.rcgroups.com/forums/showthread.php?t=649178

EDIT: Still can't find that color print! I could have sworn it was with the single page outline print. Now I'm going to be tracking that down all day. It isn't in this thread either as far as I can tell.