RE: Hangar 9 produced the Twin Otter!
 

guys

new to this tread, but I am looking to get a H9 Twin Otter, a few questions and a photo request.

I would like to put in a pair of Power 32 motors and some 60 Amp ESC and run them on 4s 4000mah lipos (have lots of these 4 cells - I fly my t-34 metor and my T-6A texan on them) but would like to run 3 bladed props,- Any suggestion on what 3 bladed prop and spinner to use???

Any issues with the build, or is it pretty straight forward???? I know H9 says it is easy, but based on the issues I had with my T-6a and converting it to electric, I am not looking for that again! :)

Picture reqeuest:
Can someon take a picture of their bird with the wings off - I hope to have enough room in the wagon to transport the bird??

Could one some one take a picture of how their lipos are installed?

Thanks, and will wait to hear back!

Bob

RE: Hangar 9 produced the Twin Otter!
 

Joemama, very, very nice work on your Otter!

I too am considering the Power 32 spinning 3 blade props. I read you had to modify the motor mounts a bit, beyond modifying the firewall (love the vent idea).

Can you post a pic of the modified mounts?

Thanks!

RE: Hangar 9 produced the Twin Otter!
 

Joe

Can you post what is the size of your 3 bladed prop and what spinner you got (and where you got it)

I am looking to get an otter, and would go with a P-32 set up with a 3 bladed prop (also what ESC did you go with???)

thanks 

love the look of the otter!!  yours is great!!!!

I am on the hunt for one!

RE: Hangar 9 produced the Twin Otter!
 

I have the batteries mounted on the front mount where the nose wheel servo is mounted. (for balance)

I leave the wing tube and the wing struts on the fus. It is just about the same width as the landing gear.

Also I used three batteries, one each to operate the left and right wings, one for rudder and nose wheel and elevator. Three recievers and switches too. This way I only have to connect two power wires for the wings. Cuts down on mistakes hooking everything up.

RE: Hangar 9 produced the Twin Otter!
 

I just got my Otter!!  going to put in 2 Power 32's and 4 cell 4000 mah lipos!!

My question is when you check the CG in the manual they show marking the CG on the bottom of the wing, but they tell you to invert the plane to check the CG

I know my low wing warbirds, I invert the plane,but I thought I on high wing plane you don't! 

DO you invert the plane when checking CG??? 

Cant wait to start the build

Bob

RE: Hangar 9 produced the Twin Otter!
 

I didn't.

slopoke

RE: Hangar 9 produced the Twin Otter!
 

I flew the Twin Otter yesterday for the first time. I'm using the electric EFLITE 25 BL, 870 KV motors and 3S 4000 MAH Lipos. It flies so scale like, take-offs are great and the landings are so slow and gentle you can put it down on the mains first and then the nose settles down ever so gently. It is a beautiful plane and a joy to fly. It took very little trimming to get it to fly straight and level. I'm looking forward to trying the flying characteristics with the flaps.

RE: Hangar 9 produced the Twin Otter!
 

I'm new to this site but have been totally impressed with the string regarding the Hanger 9 Twin Otter. I'm going to get one soon, but need to ask folkslike JoeMamma about goingto 3-bladed props. i did not see in any string the recommended prop size for 3-bladed and also wonder if the 25 size electric motor can turn them or do I need to go tothe 32 size withthe 3-blade? This is one beautiful airplane and I want to do itright!

RE: Hangar 9 produced the Twin Otter!
 

Hello:
On the second flight, I mounted my GOPRO camera. Here is the video in High Defintion: http://www.youtube.com/watch?v=BM9ulY27f7o

I now have about 6 flights on it and I have yet to find any bad flying traits or the need flaps for landing, even on a paved runway. It floats and floats and settles in nicely on the rear wheels first and then you can slowly ease off the elevator to let the nose wheel touch ever so gently. The plane flies very scale like, not an abundance amount of extra power, but adequate with the Eflite 25's and APCE 12 x 8 props. I am pulling 41.5 amps on 3S 4000 MAH Lipo batteries, and 465 watts from each motor at the peak power. The first flights, I got 140 Degrees Fahrenheit on the speed controllers. I drilled another 1/2 inch hole on the firewall and dremmeled out near the bottom of the motor mount area. Improving the airflow dropped the ESC operating temperatures 20 degrees. RPM's on the motors are around 9400.
It is indeed a wonderful plane to fly!
Mark

RE: Hangar 9 produced the Twin Otter!
 

Hi tomkip,

The only reason I used the large 3-blade props was I was trying to achieve a scale look to the real U.S.A.F. UV-18 Otter. I also painted the prop tips and prop spinners in a scale fashion.

The only scale-like 3-blade props I could find were Master Airscrew's. Unfortunately these are not electric-style props so they are very heavy. Consequently, I needed the bigger Power 32 motors to spin those heavy props. One downside is I'm pulling (from what I remember) over 80 amps on takeoff. Another downside is using my existing, smaller 4-cell 3300mah lipos.........flight times are only about 6 minutes.

From the fellahs I've met on the net, they are telling me the Power 25's will work great on this Otter, but you must use 2-bladers'.

This is the price I pay for a scale look.

Joe M.

RE: Hangar 9 produced the Twin Otter!
 

For tomkip,

The Twin Otter thread didn't take off here at RCUniverse like it did over at RCGroups.

Plan on spending maybe 2-3 evenings reading the Otter thread throughout 2047 posts covering 137 pages. A lot of great information.

http://www.rcgroups.com/forums/showthread.php?t=859171

Joe M.

RE: Hangar 9 produced the Twin Otter!
 

Thanks JoeMamma for the info and tip. Nice job on your Otter! I really appreciate your help!

RE: Hangar 9 produced the Twin Otter!
 

Joe,

I've been reading the string on RCGroups for the Twin Otter (wow, that's good stuff). I'm half way thrugh it. One of the early on posts had this question: "I want to use 3-bladed props & Power 25 motors. Would 12x8 3 blade work?" The answer was "12x8 3 blade is too much prop for Power 25, even with a 3S pack. Would have to drop down to the 11x7 either MAS or Graupner props...." So,here's my question along those same lines: If I want to stay with the 25s and use the suggested 3S 3200 batteries (since I have a number of these already), will I be OK turning the 11x7 3 blade in your opinion?

thanks in advance for your advice on this!

Tom

RE: Hangar 9 produced the Twin Otter!
 

Hi Tom,

I really can’t tell you if an 11x7 3-blader will work with an EFlite Power 25 and a 3-cell 3200mah lipo, as I have never tested this particular combination. Because I’ve never tested this combo I don’t know the maximum watts or amperage output. If I could guess, I would say to use a 2-blade 11x6 for starters.

If you are going to spend time playing with electric powered models, I hope you have invested in a decent watt/amp meter. This is probably the most important tool you can invest in.

I made up a simple test stand using some scrap lumber I had laying around the shop. This stand has tested a multitude of power combos. If I want to test a new or different brand/size/type of motor, I just add a few more adapter holes to my wood stand.

Because of the multitude of combinations of motors, lipos, ESC’s and props, you will need to make up a test stand and do your own testing. Your test stand doesn’t need to be fancy, just some way of temporarily mounting up different electric motors. I remember the days before using a test stand when I simply held onto the motor with my fingers. After almost losing a set of fingers twice (OUCH), I made up the test stand.

After I complete a test, I record the details to my log book. These details include the motor brand/size/type, the prop size/number of prop blades, the lipo brand/size/amperage/cell count, and finally, my watt and amperage outputs. I keep these test results for future electric power combinations.

Joe M.

RE: Hangar 9 produced the Twin Otter!
 

For those interested in flying 3 blade props. I have found the MASter and Graupner's to be really heavy. The Master are not efficient at all, the Graupner develop more thrust, but also are power hungry. It simply takes extra amps to turn these.
The solution. I started using EMP propellers, from Hobby King. They call them TGS sport. These propellers are actually designed for electric, have a blade shape very similar to APC electrics. They are far lighter than anything out there designed to handle any power.
They make an 11/8.5 and a 12/8. The 25 Eflite might turn the 11/8.5, while the 32 will turn the 12/8 ( actually close to scale size).
An extra bonus is the price, about a third of the others.
I'm currently using 12/8/3 EMPS on a Twin Otter (not Eflite's) and a 84" Buffalo, along with a 15/8/3 EMP on my 96" Turbo Beaver. I have found them far better balanced out of the package than any of the others.
I used the Dubro 2" 3 blade spinners, had to open the blade notch, but they spun up fine. I believeHobbypartz carries them in the US FWIWflytreetimes

RE: Hangar 9 produced the Twin Otter!
 

Thanks ofr the great advise, JoeMamma. I'll take it! I finally finished reading the entire TO string on RCGroups... great info all around. Hope to have 2 good flying days here in the Carolina mountains and plan to also take in the Electric Joe Nall. Planning on ordering my Twin Otter this week, too! Busy week!

Tom

RE: Hangar 9 produced the Twin Otter!
 

I can confirm that the Twin Otter does VERY well on the Power 32/60 amp ESC/4s4000 lipo setup. I am currently using 13x6.5 APC E props, with opposite rotation.

I maidened mine last Friday. Hopem all the other Twin Otters in this thread did or do as well as mine did! Really a great flying aircraft with no vices whatsoever.

RE: Hangar 9 produced the Twin Otter!
 

Attached are a few photos of my completed H9 Otter. Stripped/glassed and finished to resemble the Norwegian special forces 057 livery. Twin Saito 62's. The nacelles had to be highly modified to get these engines to fit and to locate the fuel tanks properly. 14.75lbs. Maiden pending the arrival of additional nerve. ;)

[link=https://picasaweb.google.com/kthmarks/Otter?authuser=0&authkey=Gv1sRgCM-f-pG_xP2ssQE&feat=directlink]Link to build progress photos[/link]

RE: Hangar 9 produced the Twin Otter!
 

Nice Work !!! Khtmarks , what size are those 3 blades you are using on those Saitos 0.62 , I am planning on using Evolution 0.36 2 Strokers and I was wondering if they had the power to swing this MA 3 Blades.. I love the looks of this plane in the original 3 Blades but I dont want to ad more weight with biger engine..

Anyone has experience with Nitro engines and 3 blades set ups??

RE: Hangar 9 produced the Twin Otter!
 

Beautiful job there Keith. I guess that is called de-ARFing, isn't it? At any rate, great outcome.

Regarding 3 blades, I've used them a lot and weight differences are rather minor. With some brands you have to go down in pitch to get the same RPMs but they are well worth it for the look you get.

RE: Hangar 9 produced the Twin Otter!
 

Thanks guys.....LOVE this plane. I was very please with the results. I have revised the nose to be a little more scale-like. Props are 11x6.

Some build/design photos.
[link]https://plus.google.com/photos/118001997929694205069/albums/5705355519989108737?authkey=CM-f-pG_xP2ssQE[/link]

RE: Hangar 9 produced the Twin Otter!
 

One question... What CAD tool did you use for the revised nose? I'm still looking for the right choice.

RE: Hangar 9 produced the Twin Otter!
 

I used Autocad for the 2D drafting and Goodle Sketchup Pro for the 3D.

More images here
http://www.rcgroups.com/forums/showt...59171&page=181

RE: Hangar 9 produced the Twin Otter!
 

Nice, I have one of these as a gift from a friend. The top hatch is missing though so need to make one.  One of the flap servos bound up during testing and fried, so I have the flaps locked up for now.  Looks like I really wont need them though, so I can maiden it as is, unless someone says otherwise.  Running Eflite 25 power motors on it. Balanced out by putting the RX battery in the nose.

RE: Hangar 9 produced the Twin Otter!
 

The flaps are not mandatory. Mine came out heavy (due to finishing, glow conversion, etc) and they are helpful. But if your bird is "stock", you should not have a problem. Good luck.