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

RM Aerobat

Another electrified 1980s design

All Topics | Latest Posts

Search for:  in Thread Title in  
Piers Bowlan12/01/2019 15:43:03
avatar
1559 forum posts
41 photos

'Redesign her', David? With a new wing structure, tailplane position, leccy conversion plus the latest bulkhead modifications, the model looks redesigned wink 2. All Nigel needs to do now is fly her, when the weather Gods allow!

David Mellor12/01/2019 16:38:48
avatar
1188 forum posts
599 photos
Posted by Piers Bowlan on 12/01/2019 15:43:03:

'Redesign her', David? With a new wing structure, tailplane position, leccy conversion plus the latest bulkhead modifications, the model looks redesigned wink 2. All Nigel needs to do now is fly her, when the weather Gods allow!

I know.....you're right, of course!

It is just that now he's built one, he knows how to build a better one and it seems a shame to lose all that knowledge..........

Nigel R13/01/2019 12:02:06
avatar
2108 forum posts
381 photos
Ha yes I'm with Piers on that one! I simply don't have the time to build a second fuselage.

Servos are now set up, lead is glued in place - all that remains is to offer a sacrificial chicken.

Roast tonight

Edited By Nigel R on 13/01/2019 12:02:50

Nigel R15/01/2019 13:52:18
avatar
2108 forum posts
381 photos
Battery hatch left on the bench at home.
 
Cowl not attached - didn't get time last night to trim the ply ballast cover.
 
Spinner not fitted
 
Despite all that, aviation was committed.
 
First thing observed, the prop was horribly out of balance. As yet, I have not put RTV on the wing saddle or canopy and the latter vibrated loudly in sympathy. With the missing hatch, a resonant effect at any speed made the noise even worse. During the second flight, the balsa chunk at the rear of the lipo came unglued.
 
Let's ignore the noise for now. As for flight itself, she goes very nicely. Take off was a piece of cake, plenty of go, and up she went. Very well behaved at low speed, as a plank wing should be. A nice moderate approach speed, with no real tendancy to drop a wing unless provoked. Smooth, surprisingly so, and very neutral. A few goes at the dive test show that a couple of degrees down thrust is about right, ditto for stall turns, showing no particular leaning to go one way over the other.
 
Could use a little more aileron, and a little more rudder. Knife edge is nearly there, but needs the extra few degrees movement that I didn't have. A slight pull to canopy was observed which I think may mean the CG could have gone a bit further back (!). The extra rudder will help initiate a snap cleanly. As will a few degrees more of aileron.
 
All that said, she is good, very good. I believe this will be a go-to model. Everything fits in the boot - no messing around putting seats down - and just two plugs and two bolts to assemble. Great aerobatic performance is icing on the cake.
 
A few snags to correct now, but, happy with that. Looking forward to a proper session with everything sorted out.
Nigel R15/01/2019 14:02:19
avatar
2108 forum posts
381 photos

Couple of quick stats from the shop log, if anyone is interested

Total build time; 120 hours.

Fuselage took approx 40 hours, the wing 35, tail end 8, covering and rigging about 25, the remainder was sorting the CG and some other small jobs like soldering the electrics.

Overall cost, 150 pounds. I already had RX & servos, everything else was bought for this project.

David Mellor15/01/2019 16:58:40
avatar
1188 forum posts
599 photos

Woohoo...... congratulations, Nigel. You've got a winner there. Well done, mate. I'm impressed.

Very, helpful of you to give the shop-log stats too, so thank you for doing that.

Nigel R15/01/2019 17:19:45
avatar
2108 forum posts
381 photos

Many thanks Dave

Engineering habits die hard!

The actual shop log is 143 entries in a spreadsheet, each being a different small (sub 2 hour) job. To make it even worse I also list them out ahead of time and estimate total required time for the project, as things go along the spreadsheet can be used to predict roughly when I'll finish the job - I knew almost for certain when I started back in May that this one was unlikely to fly before Christmas!

It sounds like way more bookkeeping effort than it actually is. A couple of minutes to update after every session in the shop. An hour or three up front to figure out the job list, and at the same time I'll run up a bill of materials and keep tabs on spending. Any notes on the design, structure, or whatnot get another tab in the spreadsheet.

Hmm, now, should I have admitted that all in public, or not!?

David Mellor15/01/2019 18:52:16
avatar
1188 forum posts
599 photos
Posted by Nigel R on 15/01/2019 17:19:45:

 

Hmm, now, should I have admitted that all in public, or not!?

 

Worth mentioning, I think. If you can't measure it, you can't manage it.

Edited By David Mellor on 15/01/2019 18:52:43

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

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

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Gliders Distribution
electricwingman 2017
Wings & Wheels 2018
Slec
Motion RC
CML
Overlander
Airtek Hobbies
Revoc
Advertise With Us
Sarik
Latest "For Sale" Ads
Which part of building a new traditional balsa aeroplane do you enjoy the most?
Q: Which part of building a new traditional balsa aeroplane do you enjoy the most?

 Research & choosing the model
 Building the fuselage
 Installing the engine and radio systems
 Building the flying surfaces
 Covering/painting/finishing
 All of it!
 None of it. I'd rather someone else did it!
 Other

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us