50mm converts to Pusher

[solentlife]

Looking to see what people think would make a FAST good pusher out of the 50mm EDF range ...

I've stayed with the Jpower range as they seem to fly so well in EDF form that pusher can only be good !

I'm looking for Speed ... stability ..... able to carry decent LiPo and motor ....

I look at all of them and literally cannot make up my mind !!

If you think Screamer is best - then sorry I forgot to add it in ... but just post a reply for it.

I'm also looking for comments from those who have converted any and suggestions of budget motor / combos etc. to do them .....

Nigel

[dahawk]

Nigel,
Glad to see you're back in action after global travel. You can cash in airline points for planes? I received my new Red Arrows T-45 airframe and have re-started the circle of life. Looks gorgeous.

I am ready to convert the Katana to a pusher and have every thin I need basically. Will go with stick mount this time. Will use the Grayson Hobby Super Mega V2 2500KV screamer.

Thinking about the F-16 to convert as well. Never really liked it in the edf configuration anyway.

Cheers,

Hawk

[solentlife]

Hi ... I arrived home in serious trouble ... health was terrible. Still feel a bit off - but getting there.

Been flying all sorts last few days - get my hand back in ...

Anyway - I'm trying to decide what would be good to convert ... I keep looking at the F16 .... with no need for air intakes to an edf - I reckon a decent battery can be lodged into the main body of the model instead of the cramped cockpit space ... balance and decent capacity solved in one.

Nigel

[stuart]

Nigel,feel better my friend...don't push the house repairs and do get some good flying in.

i was at work today and tried researching the edf's your talking about but didn't find the bare bones pricing except for the sky angel which is $27 here in the states. could you post direct links for the jpowers bare bones kits you want to convert. I'll gladly go along and we can start a new need for speed thread. i do like the way the sky angle looks but haven't looked up how the battery fits in.

glad your back home and hope you get the pkj twin up and speed recorded.

[dahawk]

Stuart, the f-16 Skyangel has a very small cabin. But as Nigel mentioned, you could carve out the floor and allow for the battery to drop to the scoop underneath. There's only one problem though. The scoop is located too far aft and the resulting CG problem will be difficult to solve. The F-16 airframe is very light in comparison to the T-45 or the Katana. It flies pretty fast stock and I recon it maybe the fastest in the series as stock. Modding will be a challenge IMO. But all we have to tell Nigel is: " It's impossible " and we'll see miracles.

I'm going to get started on the Katana conversion. Learned a lot from the T-45 conversion so this one should be a snap. The interesting part about this one is that it has a rudder. A knife edging pusher prop !

Let me know what you guys decide to do.

After my flying experience the last few times out I should take up golf again.

-Hawk

[stuart]

the sky angel shipping cost is$20 or $29 buck. this makes the unpainted version a bit pricey.

now to check out the kantana model.

[dahawk]

Check with both Toysonics and HobbyB ?

[solentlife]

Originally Posted by stuart

Nigel,feel better my friend...don't push the house repairs and do get some good flying in.

i was at work today and tried researching the edf's your talking about but didn't find the bare bones pricing except for the sky angel which is $27 here in the states. could you post direct links for the jpowers bare bones kits you want to convert. I'll gladly go along and we can start a new need for speed thread. i do like the way the sky angle looks but haven't looked up how the battery fits in.

glad your back home and hope you get the pkj twin up and speed recorded.

Thanks Stu ...

I put down to ill health - but my trusty old Cessna (2.5yrs vintage - never a major crash) - broke it's wing yesterday in wind and too much flaps in too low, too slow turn ! She cartwheeled in - BHAM !

HK Edge racer folded a wing in flight ... BHAM !

All back repaired though !!

Stuart - JPowers and Skyangel are same people ... Skyangel is sub company of the JPowers syndicate.

The F16 ... yes it has a scoop air intake under - but my idea is to carve out into the foam just ahead of that - so LiPo sits up into fuselage further back allowing a larger heavier pack. The cockpit will then be empty basically except for RX / ESC.
There's no need for air flow to an EDF - so not a problem to hack into it there.
The rear mounted motor will also help.

I've just run up a Funfighter 1950kv motor (used on the Rarebear) ... 17A on 5x5 prop and 4S 1600 LiPo .... now that's not bad and plenty of OOOOMPH !! It's fitted to the modified Snice Mitar scratchbuild ...... just needs finishing of.

My Twin ... as soon as a good day for it - will try again.

Nigel

[Wildflyer]

I have an idea that might help with CG management although there may be problems I haven't thought of.

Mount the motor in approximately the original position it would have been in the EDF plane but with the prop shaft facing to the rear.

Couple the motor to an extension shaft supported by ball bearings in streamlined brackets to prevent the shaft from bending or whipping.
Then mount the prop to the shaft using a collet type adapter.
This would allow good airflow around the motor because it would still be in the original ducted tube, the propeller would be drawing air through the tube as well as around the airplane.

I used to race RC hydroplanes in the 70's and this is basically how a boat is hooked up, also very similar to the P-39 Aircobra, just reversed. Attention would have to be given to the thrust line.

The plane would look almost stock, even on the ground, and the prop would be almost invisible in flight.

[solentlife]

Hi Wildflyer .... I watched a vid of someone who did the shaft extension, but for me - I would be worried as I'm not an engineer. I like very high kv /rpm and that on a diy shaft ? I don't think I'm good enough to make it.

The motor being right at back end with prop as normal - in my opinion is better for CoG ... as it allows a heavier LiPo to balance it.

All ideas are welcome though as it takes more than one idea to solve it ...

Nigel

[Wildflyer]

In the race boats we just used a simple 2 pin universal joint mostly so we could remove the motor easily ( racing nitro motors ).
The connection between the motor and shaft might be as simple as a coupler with set screws or a U-joint like we used, the bearing are easy to get.

With the 60 size full race motors on 60% nitro some guys were putting at least 5 hp at 25,000 + RPMs down a 3/16" shaft, with bearings about every 4"

All speed records in boating are held by brushless motors, so they must have everything available. Someday I might get back into RC boating.

[solentlife]

When I lived in UK .... I had literally any RC model I could get ... boats, cars, Jet boats, Heli's, planes ...

I know full well the universal joints and shaft tubes / bearings etc. My fastest was an MFA Spearfish with piped 61 on stainless prop. Then we came down through various glow powered stuff to the Veron Police Boat with 10FSR ..... I had the Veron County Class Destroyer as my party piece with twin electrics.

Back to the pushers ... the 50mm T45 I have converted has a 3800kv 250 heli motor, 5x5 prop on a metal mount in tail end ... this balances out nicely a 1600 4S LiPo up front.
The original T45 as a 50mm EDF can only carry a 1000 3S up front balanced on recc'd CoG point without resort to tail weights. My second still as EDF has 25gr of metal at back end to help counter the 1600 4S I put in up front. She still balances nose heavy, but flies well.

Nigel

Originally Posted by Wildflyer

In the race boats we just used a simple 2 pin universal joint mostly so we could remove the motor easily ( racing nitro motors ).
The connection between the motor and shaft might be as simple as a coupler with set screws or a U-joint like we used, the bearing are easy to get.

With the 60 size full race motors on 60% nitro some guys were putting at least 5 hp at 25,000 + RPMs down a 3/16" shaft, with bearings about every 4"

All speed records in boating are held by brushless motors, so they must have everything available. Someday I might get back into RC boating.

[dahawk]

Nigel,

On the Katana, I'm going to try to mill out a shallow slot for the 10mm stick mount and epoxy it in. Not sure about the thrust angle. Should be an interesting conversion as this one has a rudder.

Hope you're feeling better !

Hawk

[solentlife]

Having made mistake of down on the T45 ... I now have it near zero down thrust ...

I think these models when you think about it - the EDF thrust is straight out that duct ..... so in my mind makes sense to have pusher prop do same line ?

With the stick mount ... I set mine so motor sits just about dead centre of exhaust tube. Meant stick was buried about half into the upper foam under fin. I also had motor outside the duct - so I can service it without cutting the duct / model to get at it. This also helps balance.

Nigel

[dahawk]

Thanks,

Not much foam in exhaust tube to mount stick. I agree having it hang from the top versus from the bottom will work best.

-Hawk

[solentlife]

T45 .... zero down thrust .... 3800kv heli motor ... 4S 1600 LiPo ... 4.1x4.1 prop ............

http://www.youtube.com/watch?v=5T-_f...ature=youtu.be

Half throttle = 88kph ........ WOT she hit 180kph on that wild low close pass ! Boy did that make my heart tremble !!

But it's insane speed with so short run time ... I'm now looking for a more reasonable motor that will not fry my 4S lipos !!

Nigel

[solentlife]

having proved to myself that the T45 does actually fly faster on pusher ... I am now looking for sensible power combo's to use !

The 3800kv 250 Heli motor draws too may amps and makes for short run time - BUT an insane speed machine !

What we need to arrive at is a reasonable amps draw motor and prop size that will push the 50mm models to speeds never seen before !

I have the Funfighter Rarebear motor 1950kv fitted to the Snice-Mitar on a 5x5 ... but I have reservations that such a motor can deliver the speeds .. not because the motor cannot drive a decent prop - but because we cannot go up too much on diameter - we would introduce torque problems ...

Guys - thoughts please .....

Nigel

[dahawk]

Nigel,

When I got the old T-45 running on the conversion, mine too screamed for mercy. Much faster than the edf version. I never did muster the courage to try 4S though. My new T-45 airframe is so nice and shiny, I hardly recognized her. Someday, she'll do service as a pusher.

I have the Rare Bear and run a 6x4 MAS . Have run her on 4S and she's the fastest bird in my squadron. Scary fast. I upped the esc to a 40.

On the Katana, I'm going with the GH super mega v2. 2550KV.Beaucoup rpms. I have it mounted straight thrust line. The battery compartment is deep and cavernous and I can get a thin zippy 11.1v 2200mah 30c 3S in there without a problem. Balances nicely. In fact, anything lighter up front and she will be in trouble. Was thinking of ganging 2 smaller 3S 1000mah's and run them in series for a 6S setup but then again, that's crazy. Or maybe run them in parallel for longer flight times.

Now for the maiden. Maybe today. Great vid BTW !

-Hawk

[dahawk]

Aft Section- Katana



My most active little guys: Katana conversion, Rare Bear, T-45 Red Arrows edf( new airframe)

Kat is all set up ready to go. Wife's Birthday and Mothers Day. Double whammy this weekend. But I think I'll make it out to the field tomorrow. Spent day repairing C-310

Have a good one !

-Hawk

[solentlife]

Flew her again today ... have to be careful of the bungee as the power curves her of to the right hard if you hit power too quick ..

But this is fun !! I can see myself investing in a few mods of 50mm's ....

Nigel

[dahawk]

Good news / bad news

First the bad:

The reborn, brand spankin new T-45 got airborne fine and while I was trimming had a brown out. Knock off corona fasst rx. Spiraled down in the trees. At the crash site all appeared okay. Canopy was on the ground about 5 ft away from the plane that had come to rest in a low tree(bush). The only problem was that a piece of the wing was broken off and is still missing. Search crew gave up looking. I suspect it tore off in the high 15m trees and is still there. Can't MacGyver a fix for this one. So, I'll head back to the field this week and see if the wind has freed the piece loose.

Now the good news:

The pusher conversion Katana flew great. Buzzed around at about 1/4 throttle and she only needed a couple of clicks of down trim. Gave her the berries and she disappears quickly. Very fast. The rudder gives this plane a nice new dimension. She'll knife edge. Encouraging.

-Hawk

[solentlife]

Sorry to hear about the demise of the new frame .... I hate it when the new pristine model goes out and then goes home looking like a herd of elephants walked over it !

Here's my old faithful from yesterday !

http://www.youtube.com/watch?v=f-ULMvv238Y

Nigel

[dahawk]

Nigel,

You're having way too much fun ! Looks and sounds great. 3S 1800mah, right?

I ordered a new main wing from BH. USD $7.00 Shipping USD $12.00 No free lunch. But then again, I should feel some pain for using the corona rx. Just ordered another Frysky fast compatible.They are reliable. $26 plus $3.00 shipping. Go figure. My luck, I'll probably find the missing piece on the ground somewhere.

Had one of those days where I said to myself: " Why aren't you playing golf instead? Brought 6 planes with me to the field. Crashed the adorable T-45, the C 310 was a no-go, the Formosa II was a no go. The PZ P51 was okay but a little boring. The Katana was very good and I never got to the Rare Bear. Was still bummed out about the T-45 going down.

The Katana saved the day. Plus, a friend sold me his Phase 3 F-16 NIB kit for USD $20.00 Not all bad. Going to set that one up for 4S.

Hopefully, get to fly this week.

-Hawk

[solentlife]

Originally Posted by dahawk

Nigel,

You're having way too much fun ! Looks and sounds great. 3S 1800mah, right?

No ... 4S 1600 ......

I ordered a new main wing from BH. USD $7.00 Shipping USD $12.00 No free lunch. But then again, I should feel some pain for using the corona rx. Just ordered another Frysky fast compatible.They are reliable. $26 plus $3.00 shipping. Go figure. My luck, I'll probably find the missing piece on the ground somewhere.

I have a Corona Dual Synth 35Mhz Rx and once I got it locked onto Tx ... seems fine, but never used it ... sits there idle.

Had one of those days where I said to myself: " Why aren't you playing golf instead? Brought 6 planes with me to the field. Crashed the adorable T-45, the C 310 was a no-go, the Formosa II was a no go. The PZ P51 was okay but a little boring. The Katana was very good and I never got to the Rare Bear. Was still bummed out about the T-45 going down.

Know the feeling well !

The Katana saved the day. Plus, a friend sold me his Phase 3 F-16 NIB kit for USD $20.00 Not all bad. Going to set that one up for 4S.

Hopefully, get to fly this week.

-Hawk

Hear a lot about the Phase 3 F16 ... but over here is not so easy to get hands on one so cheap !

Here's the 70mm one I have and it's successful flight ....

http://www.youtube.com/watch?v=9rPHbaWXHsY

and then failed bungee where rail fixing caught the servo arm !! Luckily she survived it OK ....

http://www.youtube.com/watch?v=zLnclmDh8eo

But now I'm wandering of the subject !!

How do you rate the Katana vs the T45 in this pusher lark ? It always reminds me of a mini Stinger ...

Nigel