Durafly Bf163 Komet with optional rocket!

[David Pearce 4]

I'm a bit surprised that there are no comments on the latest HK Durafly release: the Messerschmitt Bf163 Komet. It has an optional rocket motor which should give club safety officers something to think about!

I also think the dropable dolly may have other applications such as pusher props to avoid the hazards of hand launching.

The video is here:

**LINK**

Edited By David Pearce 4 on 12/04/2015 11:06:57

[Dave Hopkin]

Yep Komet owners are going to have many happy hours poking around in the long grass looking for the take off dolly

[David Pearce 4]

True, and a runway littered with pairs of dolly wheels would be a nuisance but I'd be interested in how the dolly works using a servo and magnet.

And I'm still surprised at the lack of interest here in the rocket power option . . .

Edited By David Pearce 4 on 12/04/2015 21:14:39

[Dave Hopkin]

Looking at the HK video its not actually a "rocket" its a low power firework that just streams some smoke

Not quite sure how it would fit with the ANO though.....

[Reno Racer]

I'm very tempted, although suspect if I did get one the fad of using the rocket, I suspect, would wear off fairly quickly. I does look like a cracking model though.

[Bill_B]

Posted by Dave Hopkin on 12/04/2015 21:20:57:

Not quite sure how it would fit with the ANO though.....

Presumably the same as S8 class rocket gliders?

[Frank Skilbeck]

Posted by Bill_B on 12/04/2015 21:35:24:

Posted by Dave Hopkin on 12/04/2015 21:20:57:

Not quite sure how it would fit with the ANO though.....

Presumably the same as S8 class rocket gliders?

I had the Estes rocket powered canard glider for a while, I only used the rocket motor for a few flights and added an electric pusher, as the cost per flight on a rocket motor was expensive but it was good fun.

[Paul Marsh]

I've just ordered one!!!

Also bought a couple of LIpo packs with the order. Where do I get C60 estes rocket motors from?

[steve c]

Ordered mine Friday and also ordered the rockets from model rocket shop got some spare ignitors as well just incase 'make sure you get the correct rockets ,apparently some of them have built in parachutes

6 rockets in a pack for£14.99 and they have a five second burn

[John Payne]

Did anyone else notice that one of the channels on the box was the Rubber? Perhaps to make it bounce better on landing......... John.

[David Pearce 4]

Anyone using rockets with this should watch the latter part of the video carefully. The rocket should NEVER be installed before switching on as it will IGNITE when switching on. Do study the video carefully before considering buying rockets.  

[Paul Marsh]

I'm going to add an arming plug, so there would be no way to ignite it without turning it on. Like on Robot Wars, needed a fool proof method if it being dead until it needed to.

[Dizz]

Ordered mine last Thursday and it arrived on Friday. Built it and tested firing circuit yesterday, did an installed C6-0 rocket test firing in my mates back garden this afternoon and all went well. Going to try a B6-7 on the bench tomorrow with the intention of generating a longer smoke trail. Test flights are planned for Wednesday afternoon after work.

Overall I'm pretty impressed with the scale looks and thought that has gone into this model. The drop-off dolly uses the same release mechanism as the drop tanks on the Avios Sea Fury and they work faultlessly every time in my experience. Off course the dolly doesn't have to be released on the runway right after take of, it can be retained and dropped anywhere convenient/sensible. Slight niggles are the swasitka transfers and the under sized pilot figure, but at least they are provided I suppose.

I carried out comprehensive checks connecting flight pack and rocket ignition in different combinations both after and before tx was switched on. I used a voltmeter on the rc switch output and I did not get the same results as shown in the video: the output stayed 0v at all times until I pushed the button. NB there are 4 fail-safe settings available on the rc switch, so maybe he had the wrong one selected when he generated the flashing LEDS in his test in the video. I am using the recessed push-button (switch "I" )  on my DX18 to fire the rocket, so I haven't bothered with the faff of fitting a late arm switch.

Looking forward to getting this one in the air; certainly going to turn a few heads when the rocket fires

Edited By Dizz on 13/04/2015 19:15:08

[David Pearce 4]

Dizz, you make some interesting points in your posting.

One thing that isn't clear is how much thrust does the rocket provide or is it more for the smoke effect?

Edited By David Pearce 4 on 13/04/2015 20:18:36

[Peter Christy]

That looks great! I had one of the Rojair ones, many moons ago! It was great once you got it airborne, but Dave Wilshere was the only club member with a strong enough lob to get it away! It was also a pig to land, as the slightest uneveness in the ground would send it cartwheeling! This one looks a much better job.

Better start saving my pennies.......

--

Pete

[Bill_B]

What's the issue with swastika decals Dizz? Aren't any provided?

Edited By Bill_B on 13/04/2015 22:08:39

[ted hughes]

Posted by Bill_B on 13/04/2015 22:08:20:

What's the issue with swastika decals Dizz? Aren't any provided?

Edited By Bill_B on 13/04/2015 22:08:39

I do know for a fact that some model airplane foamie manufacturers no longer produce the swastika as a decal, they use a small version of the black cross used on the wings and fuselage in its place.

This may be due to the fact that Nazi symbols are banned in Germany and Austria. This does mean the models are no longer historically accurate, and in fact the swastika is an old middle east peace symbol, so it does not really makes sense.

[Dizz]

Posted by David Pearce 4 on 13/04/2015 20:16:33:

Dizz, you make some interesting points in your posting.

One thing that isn't clear is how much thrust does the rocket provide or is it more for the smoke effect?

Edited By David Pearce 4 on 13/04/2015 20:18:36

According to the Estes specs the C6 motor peaks at 14N (~1.4kg) thrust on ignition (I suspect due to the inreased surface area of the domed recess the igniter sits in) but then gives a steady 4.5N (~0.46kg) for the remainder of the burn. Overall burn is 1.8 seconds. I held the model yesterday during that test and you can feel the punch, but I really don't think it will make any difference in flight because it is such a short duration. Definitely for the "wow" effect.

[Dizz]

Posted by Bill_B on 13/04/2015 22:08:20:

What's the issue with swastika decals Dizz? Aren't any provided?

Edited By Bill_B on 13/04/2015 22:08:39

They get around the sensitivities by splitting it top and bottom and it isn't easy to line up without leaving a gap/over lap. The transfers seem to be a cross between sticky vinyl and dry rub. They are nice and thin, but somewhat fragile. They do "grab" and when I tried to re-position one to line up properly it tore. The photo makes it look worse than it is, but it still annoys me.

Edited By Pete B - Moderator on 14/04/2015 19:33:02

[Paul Marsh]

Well, mine came today, at work. Quite impressed with the speed it came, considering I only ordered in Sunday night and was off into the post by mid morning on Monday.

Also, regarding the Swasticas, I suppose it was to get round the sensitivities of having such a logo present, but still suppling it and upto the end use weather to use them or not and how they are arranged - quite cunning!

[Dizz]

Forgot to say that I did the rocket motor with delay test this evening. It was a spare C6-3 rather than the B6-7 I mentioned yesterday.

Firing circuit worked as advertised/expected again.

Tracking smoke was weak and IMO wouldn't be very visible in the turbulent wake when flying.

With the open end capped with epoxy, the delay charge (used to pop the parachute in a rocket) is far more explosive than anticipated and blew the ceramic nozzle clean out the back of the motor tube. It didn't damage the model, but it was v loud and surprised us plus the neighbors. I won't be trying that again and will be sticking with the recommended C6-0 motors.

What the nozzle should have looked like:

 

What it actually looked like:

 

But at least the epoxy plug stayed in place and protected the model:

Edited By Dizz on 14/04/2015 22:00:12

[Paul Marsh]

[Chris Jones 7]

Test flying mine today after it arrived yesterday.

On first inspection I was really impressed but as the "build" progressed there were a few niggles. The aileron push rods were too thin to actually secure in the screw on clevises, I adjusted and epoxied in place. The dolly drop mechanism did not have the magnets in, fortunately I had some so it was just a case of trimming to fit in the rotating slot and hey presto. And suprisingly for Durafly there is no mechanism included for securing the battery, I hate relying just on Velcro on a flat surface so once the CG has been established I will probably fashion a ply plate with a strap.

Such a shame that QC issues have soured what should be a great experience with what I think is a great looking model.

[Paul Marsh]

I've got mine finished. Using the DX6 and voice, so a Spektrum AR610C rx is fitted and will have all 6 channels used up. Fitted the rocket ignition switch, but need some rockets.

On the voice, "Ignition" literally means ignition, and throttle cut and Gear down - or off!

[Chris Jones 7]

Flew mine today and I think the CG in the manual is Wrong!

First flight I had the CG set to where the manual stated. To do this my battery was approx an inch maybe inch and a half further forward than the position that is shown in the the product video by Stuart. The model didn't want to launch and when it did it quickly rolled left and went into a series of high speed stalls resulting in a crash and some minor damage.

After repairs I set the battery to the position shown in the product video which resulted in the CG being way aft of the stated position in the manual. Flew lovely! Guess the manual is wrong.