HET F-18

[Alastair Place]

I was wondering if anybody out there has got or built a HET F-18?

I an just in the process of putting mine together and looking for a bit of advise.

I was going to use HS-55 servos but I’m not sure that there are quite up to the job as I was trying to use what I already had spare with out buying more. I have got a CC 60 amp ESC to go with a Typhoon EDF 2w-20 and Wemotec 'Mini' Fan 480.

Now when i put the motor in the fan housing and put the fan blade on and tighten up the prop shaft adaptor nut i causes the motor to bind, if i loosen the nut off (to the point of where it is clear of the blade housing) it will turn freely, but then there is nothing to retain the fan on the shaft.

The fan blade does not touch the housing with the nut on or off, i have going through the assembly instructions a few times to see if i have missed any thing but all seams correct, am i missing something here as i spent 2 hours last night trying to work this out and got no where.

Any help would be great

Al 

[Alastair Place]

I'll take that as a no then

Well i thanks to all the input i managed to work out why the motor was binding, I have got the plane about 95% finished, all though that's not saying much as comes about 90% complete to start with lol.

I hope to get it finished this week ready for the weekend. 

[James Hindle]

Hi just read your message, I have the F-18 (good choice !). I guess that you have put the shaft adaptor too far in causing the rotor to bind on the stator.

Check out this page for plenty of help installing the minifan

http://www.warbirds-rc.org/artman/publish/HintsTips/Wemotec_-_Mini480_Fan_printer.shtml

[Alastair Place]

Hi James

Yep i did it took we a while to work that one out .

Thanks for the link.

[Alastair Place]

Hello James or anybody else that has an HET F-18

 Would it be possible to show me a photo or tell me how you secured your battery in place 

Many thanks

 Al

[Tom Foreman]

There is a full build through of the HET F18 on the Warbirds-rc Site here

Cheers,

Tom

[Alastair Place]

Thanks Tom

I found that from the link above, it was very helpfull  But i was just wondering how people had secured there battery in place.

I have got a 3s 3700 mah Flight power lipo that puts the balance point spot on the recommended CofG, but i moves about quite a bit and was not sure that Velcro would be enough to keep it in place, so i just wanted to see if anybody had come up with a better solution.

   

[stuey]

On my F-16 i have got velcro along the length of the battery and the fuz, with a velcro strap at 90deg to it half way along epoxied in so it looks like a cross. It gives you the chance to move it back and forth, and the security of a strap around the cell so it can't detach itself from the velcro (in theory!!) I will try and add a pic later to make it clearer.

[Tom Foreman]

Velcro holds my 4s1p 3700 in place in a MPX Twister Jet, although saying that I did have a MPX Gemini Biplane eject its battery during an outside loop. I was very fortunate to find the battery and ESC intact after a mass search of the model field police style. The Biplane just settled into a gentle inverted spin and just broke a prop.

But as Stuey says use a Velcro Strap, I use one on a Dualsky Extra to hold a pair of 4s1p 2600s in place.

Out of interest, I thought you said you were fitting a 2w-20 motor, won't this be a little tame on 3s1p, I run mine on 4s1p!

 Tom

[Alastair Place]

Tom, Stuey

Thanks for that i'll go down the velcro route, I was thinking that i might try and make a battery box but i think i'll keep i simple and go with the Velcro.

Tom yep your right i have fitted a 2w-20 motor my thinking was get the maiden and few flights on the 3s then put my 4s in once i have got an idea how it flys, do you think i should just go with the 4s from the start? 

[Tom Foreman]

Yes, 4s1p is the way to go, you will have plenty of thrust for take off and then throttle back for normal flight. With the 3s1p you might struggle on take off (although a bungee would work OK) and would probably have to fly on full throttle to keep it in the air.

Out of interest I find on a 4s1p 2600 on the 2W-20 + wemotec mini fan she pulls 48A to give 630W

On 4s1p 3700 on the 2W-20 + wemotec mini fan she pulls 62A to give 730W !!!

PS - on 4s1p A123 2300 (equivalent to a 3.5s1p Lipo) she only pulled 34A to give 430W, just to give you some idea how it will perform on 3s1p lipo. You might get a few amps more depending how well the larger 3s1p 3700 holds voltage.

Cheers

Tom

[Alastair Place]

Thanks for the heads up on the figuers Tom

 Think i'll just go straight with a 4s, it will have to be bungee launch as there is no way i could ROG where i fly. plus i have just bilt myself a bungee for this and for a few other planes that are just a little bit too big for one person launch. 

[Tom Foreman]

Cool, look forward to hearing the flight report, should go like stink!

Tom

[stuey]

Here is a pic of my velcro arrangement, may make more sense now. Gives me the flexibility of forward and back adjustment, and hopefully security too.

[Alastair Place]

Thanks for the photo Stuey, It all becomes clear now.

Tom i'll make sure i give a full flight report

Once again guys thanks for all your help

[James Hindle]

Good luck with your maiden, my HET F18 uses a 4S 3700mah FP lipo with a het 2w20 in a wemotec mini fan, it goes like a rocket, I can't get the embedded youtube thingy to work so here is the link to my flycamone version handlaunch is not a problem with a 4s setup !

 http://uk.youtube.com/watch?v=EbYfX0ZKSmc

[Bruce Richards]

Great vid I love the sound track

[Alastair Place]

Thanks James

Cool Video, well never got to the maiden this weekend as it was just too wet and windy so looks like it will have to wait until this weekend if the weather is better.  

[Alastair Place]

I have been a little slow on updating my flight report on F-18 so after a few flights I thought I would let you know how I got on.

On the first flight I put my bicycle clips on installed the battery and as I was on my own I decided to use my bungee as I wanted to have both hands on the TX from the off. I tested every thing twice just to make sure, then a man walking his dog stopped for a chat so I put him to good use so I could do a quick range check, I looking good. So I connected the tow ring took a deep breath and stud on the pedal then cracked the throttle open and away it went with no problems got to about 3 mistakes high (very quickly) no trim required flying straight an level so I decided to do a few circuits boy this thing is fast, but I forgot to set the timer on the TX and half way through a loop the motor cut but I was able to dead stick it in.

Put in a second battery adjusted the amount of expo and increased the rates and off I went again now having more control I was really starting to like this model and I remembered to set the timer this time all back safe and sound...

Now as I only live two minutes walk from the field and wanting to make the most of the weather I pop home but the batteries on charge and 2 hours later I was back in the field, set the bungee up checked every thing all ok I was good to go, I hit the pedal and off it went the plane started to roll right I corrected this then it just banked right and would not respond, I ran out of room and went straight into the trees.

When I got to the plane it was not looking good the wing had gone (I still have not been able to find it) left side vertical stab ripped off, left side elervon had been ripped off the battery was hanging out of the side of the fuse with the battery hatch was still in place so I picked up all the bits that I could find went home and did some testing, both of the elevon servos where not working, I put the left one down to crash damage but there was not damage to the right one, so the only thing I can think of the that this servo failed. In hind site maybe I should not have used HS 55.

I intend to get another one but this time I think I’ll use HS82MG'S 

 

[Tom Foreman]

Thanks for the update Alastair, sorry about your loss. What TX & RX were you using out of interest? I fly a Phase 3 EF16 on a pair of MPX Nano servos, equivalent to the Hitec HS55, the only problems I have had is breaking gears on bad landings in rough grass (elevons grab in the grass). Am also thinking of upgrading to metal geared servos for this model (or remember to flick the low rate switch for landings). Might have a re-think of using an HS 55 on the elevator for a West Wings Hawk that I am currently building. Might be better to use a MPX Micro servo (HS82 Equivalent but not metal geared) that I have knocking around. Hope you have more luck next time. Tom

[Tim Mackey]

Sorry to hear that Alistair - sounds like it was going well up 'til then

[James Hindle]

I was always dubious about bungee on the HET F/18 as the tailerons were below the wings and so a propensity for them to catch on the ramp (i used a rail launcher) a good throw is all you need......

[Alastair Place]

I was really happy with the F-18 ,Well i know what i going on my XMAS list now  

The TX is a Futaba 9C Super and the RX is a Electron 6 DC

I really like using the bungee (plus i throw like a 6 yr old girl) my GWS F-15 goes really well off the bungee and that has the servos exposed. as of yet i have not had the tailerons catch on the launcher but there is always a frist time.

[Alastair Place]

After having a sceond look at the in daylight it looks like it could be repaired if i could only find the wing to see what is left of it, Or does anybody know if you can get spares.

If i could get  spare set of wings i could repair the fuse.

I know everybody wants to see a photo, i think i caught it just about right in the light