By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Höllein Inside f5J kit

All Topics | Latest Posts

Search for:  in Thread Title in  
Devon Slopes22/02/2020 08:15:45
59 forum posts
42 photos

I'm most of the way through building this kit, and realised we had not got a thread for it on this site. Although I will build it with a motor, my aim is to see how it will perform on the slope in pure glider mode.

So, aside from being interested any experience with this kit, what prompted me to start the thread is to ask if there are thoughts out there on Tx setup. The instructions don't suggest using any reflex for the ailerons when the flaps are down. Likewise there is no suggested aileron differential. Has anyone experimented with this?

PatMc22/02/2020 16:22:25
4406 forum posts
527 photos

I have an unstarted Hollein Introduction which is the non aileron version of the same model. There are several threads on both models in the RCG site here's a search result for the Inside.

BTW I downloaded an English translation of the Inside instructions from RCG.

David Hall 922/02/2020 16:57:17
262 forum posts
15 photos

The "inside F5J" is very light for a sloper..

I have one, built and ready to cover (enthusiasm stalled at the moment). I'd planned to use it in thermal competitions. It will be setup simply at first, similar amounts of reflex and camber on all ailerons/flaps for flying and speed. ailerons on the outer and maybe 50% aileron on the middle, none on the inner. The inner only will have up to 8o degrees of down as braking (as in all my other F5J planes), but have not yet thought of crow braking (I don't think it will need it).   This arrangement will use 8 channels, my present max. 





Edited By David Hall 9 on 22/02/2020 17:10:39

Edited By David Hall 9 on 22/02/2020 17:11:57

Devon Slopes10/04/2020 18:30:34
59 forum posts
42 photos

I agree, David, it is very light for a sloper, but its for those days when I get to the hill-top and wonder where the wind has gone. Also the Dartmoor Slope Soarers have a nice flat-field site where I’ll use it in powered mode.

Anyway, here is the finished item, all ready for when we are allowed out again.



Devon Slopes10/04/2020 18:35:48
59 forum posts
42 photos


Out of interest I've kept an eye on the weight as I've gone along, and compared it with the table Hyperflight give.I've taken structure to include all the hardware (i.e. clevises and the like). I got to 615 grams pre-covering, and then added 150g in covering. Some of the numbers are estimates for reasons I'll explain below.

Devon's Hyperflight

Structure 765g 790g

Wiring 40g 25g

Rx 10g 10g

Servos 95g 82g

ESC 30g 30g

Motor 75g 43g

Prop/Spinner 30g 20g

Battery 100g 100g

Total 1145g 1100g

My Inside's current weight is 1190 grams, but I know this will come down to about 1130 grams when I remove various telemetry sensors and get a smaller ESC (the 30 grams I've quoted above). As you can see something is wrong with the arithmetic above compared to my actual weight to the tune of 15 grams, which could be rounding errors, or the estimate for the wiring, which was crude.

The main warning to come out of the careful weight watching is keep an eye on the weight of the covering. I used Oracover, which varied from 102 grams per square metre for the fluorescent orange, to 54 grams per square metre for the clear covering I used on the fuselage. I used Oralight for the tail surfaces as the instructions tell you to. There is around 1.75 square metres of covering on the model, so gaining 50 grams by careless covering colour choice can happen.

Next up on the differences in the table are the motor, spinner and prop. Not sure what to say here, other than that I have been cautious on the motor, to make sure I have enough power. But all-in-all the Hyperflight table seems to be a very good set of planning assumptions.

David Hall 925/04/2020 12:05:47
262 forum posts
15 photos

Good info... Have you balanced for the CoG yet, having used a motor much heavier than the Hyperflight example?

Mine has come out of the box again.. adding wiring then to be covered.

Devon Slopes25/04/2020 16:44:06
59 forum posts
42 photos

Hi David,

with the motor in and prop and spinner on, but no battery or ESC it took 130g in the nose to balance it, which I intend to supply with a 10g battery I have and a 30g ESC. The reason for the answer being in the future despite having finished the model is that I have it set up at the moment with a whole load of telemetry sensors in and a 40g ESC I happened to have lying around. That little lot has to sit quite far behind the hatch in the fuselage to get balance.

So I guess the good news is that I won't need any lead in the nose. On the other hand, given the heavy motor, it implies I must have built the thing tail heavy - despite using Oralight for the tail feathers.

Let me know how you get on,


Devon Slopes26/04/2020 19:42:11
59 forum posts
42 photos

Sorry, that should have been a 100g battery!

Devon Slopes24/05/2020 14:36:04
59 forum posts
42 photos

Having now tried without the telemetry gear in, it seems the above best-guess was wrong. Rather than 130grams to balance before putting in the ESC an battery, it appears only need 100grams, so I'll be going for a 70g battery and 30gram ESC (if I can find a suitable one).

Devon Slopes29/06/2020 17:50:44
59 forum posts
42 photos

So, a couple of weeks ago I got the chance to maiden my Inside F5J. In earlier test glides I had already discovered it takes rudder as well as aileron to turn, so I had coupled the two for the first flights just to keep load off me as pilot.

The model is powered by a 4-max PO-2834-910 motor (thank-you 4-max for the advice), which drives an Aeronaut 13” x 5” prop. As this stage all I can really say is that it’s certainly not very wrong. I got climb rates of 5 m/s, and maybe 7m/s, but need further tests to see what can really be sustained. The current peaks at about 20A. Looking at the overall consumption and given my 850mAhr battery, I’m predicting about 15 minutes flight time without lift.

Now awaiting some calm weather to do some more testing.

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
electricwingman 2017
Sussex Model Centre
Advertise With Us
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!