Limbo Dancer Alternatives

[GrumpyGnome]

18 hours ago, Steven Hurd said:

The Bill kits touch and go looks a good alternative, I have heard they fly very well. I would like to see a build log, and electric conversion if anybody decides to get one 

 

Steve 

There is a thread (think it's 'Bills Kits anyone") about just that... 🙂

[Piers Bowlan]

I am surprised no-one has mentioned Mike Keay's Basic 3D. Available from Sarik Hobbies as a plan, cnc parts only, or complete short kit. Has been on my build list since was printed as a free plan in RCM&E but I haven't got around to it yet. It is for IC but several builders have electrified theirs. Looks a pretty simple build.

[Don Fry]

I had a Basic 3D when it came out. I think it was a magazine free plan. 
Fine flier, but mine was lost to elevator flutter, so if a did another, I would fit a balance weight. One caveat, when I built it from a plan, if I had a choice of 3 bits of wood to do a job, I pick the lightest, and overcooking the lightness may be a factor. But easy build, cheap. If I built another, ribs, formers would be balsa stiffened Depron. Cheaper, lighter.

[Piers Bowlan]

1 hour ago, Don Fry said:

I had a Basic 3D when it came out. I think it was a magazine free plan. 
Fine flier, but mine was lost to elevator flutter, so if a did another, I would fit a balance weight. One caveat, when I built it from a plan, if I had a choice of 3 bits of wood to do a job, I pick the lightest, and overcooking the lightness may be a factor. But easy build, cheap. If I built another, ribs, formers would be balsa stiffened Depron. Cheaper, lighter.

This was the original article in RCM&E.

[Don Fry]

Cheers Piers, memories return.

I had the clip wing version, Irvine 52, a pipe that helped it go uphill, tuned for torque, not revs. 
Hoot. 
Guilty memory returns, catastrophic failure was in a full power dive.
Thought process. What’s that funny droning noise, bits falling off, hit ground. 
Perhaps earlier observations were misplaced. Over power it, overstress it, it bites. Not surprising. But it was a very nice flier. 

[Piers Bowlan]

Re-reading the article again Don, Mike said he used 'hardwood on the elevator l.e and tail plane t.e.' also 'fabric hinges to spread the load and avoid flutter' (to paraphrase). So perhaps the elevator is a weakness with this design, especially with an irvine 52 up front! Fun though 😁

[Andy Gates]

I loved my Basic 3D which I must add was electrified and considerably lightened.

It was my go to electric model for quite some time, I was actually flying it in the fog when everyone else with their IC models were grounded.

White wings did not help visibility of the model in those conditions but I was able to fly it around at the edge of visibility as the turning circle was amazing for its size and due to the light weight, it flew very slowly.

The only fault it had was that the cheap servos I had fitted were very notchy although it did not seem to affect the handling too much.

Edited October 18, 2022 by Andy Gates
poor typing

[Don Fry]

I have a vague memory, two episodes of flutter. And I installed a tailplane brace? Didn’t work obviously. 

I am REALY thinking here, I want a hack this size. Panics are great, had a few. But one wing is less effort, and a flight envelope less than one mistake high, means it can’t be precious. Hence a Limbo Dancer.
Basic 3 D, nice flier, cheap, and today, a carbon/balsa spar would give stiff. 
Back then I was into Du Bro hinges. Don’t know why the hinge can alter the harmonics of flutter? Nowadays a furry hinge gets glued in for this. 

[Piers Bowlan]

1 hour ago, Andy Gates said:

I loved my Basic 3D which I must add was electrified and considerably lightened.

It was my go to electric model for quite some time, I was actually flying it in the fog when everyone else with their IC models were grounded.

You obviously enjoy a challenge Andy!

Did you use a 3 or 4S LiPo for your electric setup?

[Andy Gates]

3S 2200mAH pack, 12 x 6 APC E prop, and a BL-2826/5 850kV motor.

Never used full throttle and because it flew slowly I never had any flutter issues.

I have a short build here.

 

I must admit Piers that I do love a challenge and especially love exploring the slow flying aspect.

 

I was challenged by a friend to build a lightweight version of the HK rip off of the Wot Trainer for IC - SC52fs engines if I remember correctly. My friend had added clear perspex flaps to his and challenged me to fly slower with my build. It was a very close run contest but the reverse of what you would expect a race to be. I called my machine a "Wot the 'Eck". Pictures can be seen here.

 

Just recently I was presented with a pair of wings and tailplane for a Seagull E-Pioneer trainer. I knew the length of the fuselage required because that dimension was on the box. So once again I have built a lightweight but strong balsa fuselage, modified the ailerons & added flaps. The completed plane is just over 20% lighter than standard. With the flaps down (90 degree deflection near enough) and next to no power applied it approaches the strip on finals slower than most of our members walk.

Edited October 18, 2022 by Andy Gates
spelling & added link

[Don Fry]

Such is the joy of not adding weight.

[Andy Gates]

I was taught a very valuable outlook when I came back into RC planes in the early days of electric powered flight.

 

Build in lightness, and build to fly not to crash.

 

Works for me!

[Piers Bowlan]

I think I now know what I want to build next! Better finish the current project(s) first!

To use the immortal words of the late, great, Derek Woodward; 'Simplificate and add more lightness!'

[Don Fry]

My experience, they all break when they hit the ground.

[Andy Gates]

Agreed Don, but here is where reducing weight really does make a difference.

 

Let us say we have a 4.5lb trainer which cruises at 30mph.

 

E=mc2

 

Energy of plane is 4050

 

Let us remove 0.5lb of weigh and assume we loose 5mph off the cruise.

 

Energy is now 2500

 

So the simple 0.5lb reduction has almost reduced the energy of the plane by half which means less risk of damage in landings and slower flight incidents. I know it does not make so much difference in a terminal dive into terra firma but it is an example of what can happen.

 

Going the other way, let us say the above machine was modified to make it stronger requiring a heavier power train so we gain 0.5lb and 5mph on the cruise.

 

Energy is now 6125

 

I know I am not using SI units so it is not quite as above but this example shows the sort of proportions.

[Keith Billinge]

2 hours ago, Andy Gates said:

Agreed Don, but here is where reducing weight really does make a difference.

 

Let us say we have a 4.5lb trainer which cruises at 30mph.

 

E=mc2

 

 

Let me stop you there Andy....This is a formula for things approaching the speed of light like electrons etc....... Maybe some good old fashioned, simple, Newtonian physics would work better maybe just F=mA?

Where the force of a given impact with the ground is proportional to it's mass?  

Or

Kinectic Energy K=1/2 mv2  

where the more massive and object is; the more kinetic energy it has to give up, when it smashes into that tree.

 

Glad to help, because I know none of your designs go anywhere near the speed of light! 🤣

 

You're welcome

 

KB

 

[Andy Gates]

You are right, wrong one, need more sleep!

 

Of course it should be 1/2mv2

 

So the figures would be 2025, 1250 and 3063. Still shows the same pattern.

 

F=ma would not be much help as we don't need to know how hard it hits but the energy it carries into the tree.

 

My machines flying fast.....how dare you🤬😉

[GrumpyGnome]

Have you seen the price of Limbo Dancer now? Currently listed at over £140 - was well under £100 before they disappeared off the website for a while.

 

Deffo looking for an alternative at that price.

 

Balsa Cabin Touch n Go looks favourite a the mo'......

Edited October 19, 2022 by GrumpyGnome
typos!

[Don Fry]

Outer zone, plan, depron, doculam covering, £30 - £40? A Limbo dancer kit is a simple thing to produce, 

[EarlyBird]

11 hours ago, GrumpyGnome said:

Have you seen the price of Limbo Dancer now? Currently listed at over £140 - was well under £100 before they disappeared off the website for a while.

 

Deffo looking for an alternative at that price.

Basic 3D cut parts and plan £30 from SLEC.

 

If they have not sold out.

[Piers Bowlan]

2 hours ago, EarlyBird said:

Basic 3D cut parts and plan £30 from SLEC.

 

If they have not sold out.

Are you sure Steve, the Basic 3D laser cut parts are £99 from Sarik Hobbies.

[EarlyBird]

31 minutes ago, Piers Bowlan said:

Are you sure Steve

Yes, I bought one.

 

[EarlyBird]

Here is a link to the full list of what they had.

 

 

[Keith Billinge]

Try the Swizzle Stick on SARIK HOBBIES I recommend the big-nose mod here. The Short kit set is still cheap at Sarik and you can get the rest of the balsa sheet from your spares box.  Wood pack and plans are currently £66 on sarik Hobbies HERE

 

[Engine Doctor]

Surprised nobody has mentioned the Cougar 2000 by Weston UK ? It's a fun fly  it cones ARTF .Very light and agile. Only ever had IC versions but electric are available.