Precedent Stampe 1/4 Scale

[Martin McIntosh]

I bought my kit from Ali Mac who had a pile of old kits at the time and what he thought was a Laser 100 but it turned out to be an 80 so took it back and went to see Jon for a 100. He said that it would be inadequate but had one of the new 155 long strokes available so I got that. Later swapped for a 180 which takes it round loops better on the same 18x8 prop. I cut the exhaust stub down to save removing it if I needed to get the cowl off.

Throw away the die crunched 1/16th ribs and make new ones from light 1/8th; also fit 1/8th birch ply dihedral braces. (you can bend the ply a bit for the sweep back and taper the spars to fit). The wing tips were particularly tricky because the supplied ribs would not fit and there are a lot of ply parts to fit together.

Pay particular attention to the tail incidence because I believe that there were two versions of the plan and guess who got the duff one. I have to fly mine with a huge amount of down elevator trim but this does not affect loops and bunts.

Before you even start on it think carefully about where the tank is to go, remembering that the model was designed for a short two stroke so you won`t be able to fit a 16oz one. Put the u/c elsewhere. My retro solution with a 9oz feeding a 6oz works very well whichever way up the model is and is shown somewhere way back on here.

[Martyn K]

Thanks Martin

 

I have been warned about the upper wing bracing. I am also planning to ditch the awful kit supplied ribs as well. I'll get SLEC to cut me another set.. from my CAD drawings just in case there have been any changes.

 

I like the idea of the piggy back fuel tanks, something I haven't tried. One of the benefits of the pumped OS is that the tank could go anywhere but I do need to look at the plan.

[Nick Somerville]

There is a brand new Laser 180 on BMFA today, which as mentioned is a perfect choice. I have one in mine but made a scale UC which mitigated the fuel tank position problem associated with the stock UC wire positioning. As much as I love Lasers, I do have a pumped OS 120 mk ll and it is a superb engine with a lot of power. Runs like a swiss watch. If you build light them it will be fine, albeit not the same unique sound as the Laser

[Martin McIntosh]

MK, why bother with SLEC since you can select your idea of light balsa and not rely on them. All of the main ribs can simply be made the same using the block method. I just cut a couple of ply ribs from one of the kit upper ones to use as templates and made them in four batches which took no more than an hour to do. I use four aileron servos so the wiring holes can be cut out at the same time, much easier than messing with interplane linkages and each can then be adjusted individually.

Got mine down to 6.25kg with the 155.

[Paul De Tourtoulon]

I have seen a few  planes use 3mm depron for ribs, easy to cut out with a hot wire, is it worth a try ?.

[Jake Bullit]

Following a Stampe  being buddied @ Southport Model Aero Club

 

[Martyn K]

Thanks all and thanks for the lead on the laser.   As I want to use this model for Scale Comps I think the 120FS would probably be OK. I am allowed to dive to make a loop. I have however put in a bid for the laser as it will deffo come in handy in the future if I don't use it on this....

 

Fair point on making ribs Martin. I am trying to be lazy TBH 🙂 

 

I have tried Depron ribs in the past. OK but I would not want to risk using them at 1/4 scale. This model needs to last and I want to avoid rework..

 

That's a great video, thank you..

 

Martyn

[Paul De Tourtoulon]

12 minutes ago, Martyn K said:

 

Fair point on making ribs Martin. I am trying to be lazy TBH 🙂 

 

I have tried Depron ribs in the past. OK but I would not want to risk using them at 1/4 scale.

A friend built his ultralight using foam for ribs, and yes it did past it's test and fly with a pilot in it.

 

 there are a few planes being built on french forums twin's included with depron everywhere.

Edited October 4, 2022 by Paul De Tourtoulon

[Don Fry]

Balsa is over engineering for ribs. Sure, build heavy, but at the weight of that one, they don’t bounce. They just have enough energy to keep going, so you can idly walk along the debris field picking up good bits. Loose weight, drill holes. Or loose more weight, use depron. Light planes fly better. 
Back in the day, we used cross cut balsa for ribs. A wood will similar properties end to end, top to bottom. Depron is by definition cross cut. 

[William Macleod]

I was up at Strubby at the caravan and visited the local club who made me feel very welcome. A member had his Stampe fitted with a zenoah 38. Flew very well

[bert baker]

Hmm I’ve been naughty again 

[bert baker]

Just now, bert baker said:

Hmm I’ve been naughty again 

Nice cowl but for some strange reason it won’t allow the G38 magneto to fit inside

 

 

[bert baker]

So I’m converting it to electronic ignition 

I really should be fitting a DLE 35RA

but the engine is new and it’s gonna have a massive trumpet 

[bert baker]

Next on the hit list is this one

[Martyn K]

I'll have a rethink on Depron wing ribs. I actually used them on a Classic Aerobatic model a few years but used balsa cap strips. I found that 6mm Depron was about the same weight as 1/16 balsa. Quite impressed. The wing has shown no sign of failure and has been fairly regularly flown.

 

 

[cymaz]

I think Bert is going to have to change his avatar

[bert baker]

To this 

[bert baker]

It’s a shadow of my mate landing in the full size Stampe

[Martin McIntosh]

MK, does that not give you problems glueing them to balsa or do you use latex?

[bert baker]

[Alan Hilton]

Hi Bert how many stamps have you got now ?

[Peter Jenkins]

Enough to post a first class letter?

[bert baker]

1 hour ago, Alan Hilton said:

Hi Bert how many stamps have you got now ?

I’ve got a original die crushed kit and one new machined kit both new in box’s for a rainy day 

 

Ive also got three that are built,there is a fourth one that my son Owns

[GrumpyGnome]

Deffo a Stampe Collector......

[Rc Danny]

Hi Bert thanks for the link I’m on my way to joining you with the stampe. Got a bit to do but hopefully it will look good and fly great when it’s done.