tony nijhuis Nijhuis Lancaster 1/9 scale

[cymaz]

I’ll go and get some wood ......

[cymaz]

Rudimentary frame made up. The engines will be tested inverted as that’s how they’ll live. The timber behind will serve as a fixing base and somewhere to put tanks, radio etc.

 

 

Edited August 21, 2022 by cymaz

[cymaz]

 

Making progress. End points on the throttle ( for trial running purposes only. Everything changes on the real airframe! ) are now done. Just the 4 tanks to do on Monday.

 

Edited August 28, 2022 by cymaz

[cymaz]

[Paul De Tourtoulon]

Is that where the expression of a flying plank comes from ?.

 

So all up and running.

[cymaz]

Not quite! Plumbing the tanks on Monday👍 

[cymaz]

Well, the test stand is finished. I have a large (4’x3’) saw horse I’m going to bolt it to and stake it to the ground.....I’m not having this careering towards me at speed 🏃‍♂️.

For those wishing detail.

SC 46a with 12x5 apc props, 5%

I will try and run it weekend after next.

 

Edited August 29, 2022 by cymaz

[Paul De Tourtoulon]

A video with sound would be nice.🥳

[cymaz]

Ummmm, I have a confession. I fired them up this afternoon. I wanted to make sure all was well before filming. I detest YouTube vids when all you see is someone flicking over an engine for the first half.

 

I knew I’d have a syphoning issue, which I did. The tanks are 1 1/2” above the carbs. When they all ran I was juggling back and forth keeping the engines going by adjusting the needles. Hardly the stuff of riveting viewing. Also I need 4 new plugs. When hitting the carb sweet-spot ( before the syphoning took over ) they all took it turns to idle nicely and pick up well.

 

But the concept worked despite the drawbacks. Once the tank height is sorted in the build all will be better. 

 

 

Sorry to ruin your fun. The video will come 📽️

[cymaz]

I’ve decided to lower the tanks by cutting holes in the plank or slinging them underneath. Buying  new glow plugs would be a wise move as well.

Edited August 31, 2022 by cymaz

[Paul De Tourtoulon]

Your silencers will be sticking out of the cowlings, wouldn't it be easier to install them sideways with the exhaust at the bottom that would lift the tanks up and keep the plane a bit cleaner and make the engines easier to start with less chance of them flooding.

[cymaz]

I had wondered about that but all the servos and linkage would have to move and be all set up again. I’ll see how easy it is to lower a tank first. There’s always plans B and C !

[Manish Chandrayan]

How about something in between ? Mount the engines with head at 7 'O' clock? 

Edited August 31, 2022 by Manish Chandrayan

[Paul De Tourtoulon]

Maybe that would wake up the neighbours so early in the morning.

[Martin McIntosh]

Cannot remember now how I fitted the 52s in mine. Even though it seems to be a very large model, there is very little room in the cowls (grp in my case). I think that I still have the not so good female mould so if you tell me the H x W x W I can check it. May be useful before you commit yourself.

[cymaz]

17 minutes ago, Martin McIntosh said:

Cannot remember now how I fitted the 52s in mine. Even though it seems to be a very large model, there is very little room in the cowls (grp in my case). I think that I still have the not so good female mould so if you tell me the H x W x W I can check it. May be useful before you commit yourself.

Thanks all. I'm going inverted as the cowls are small, nice to have them neat and inside. It will make baffles easier! .....Watch this space 

[cymaz]

Well 1/2 hour later.....repositioned the tanks under base board, drilled a multitude of holes and reused the cable ties. Filled up a couple of tanks and primed the carbs. No syphoning and no fuel run back into the tank. Here’s hoping🥺

 

Only took a couple of pictures but I’m sure you’ve got the idea. It’s not a pictures but the tank stopper is half a gnat’s dodah under the carb spray bar

 

Edited August 31, 2022 by cymaz

[Paul De Tourtoulon]

i can hear them running already.🥳

[Nigel R]

eagerly awaiting video of the four beasties on the go

 

[alan p]

Hope the plank isn't bolted to the bike 😈 this should be interesting 

[cymaz]

Don’t worry,

 

Engine run mush better this evening. I’ve ordered some new glow plugs as the others were all gash.

Once it’s all sorted...the video will come x

[cymaz]

Ok, I’ve put the new plugs in. OS number 8. I’ve also placed the engines sideways. And put the tanks in their original place. The engines are running much more consistently. There is still more work to do. I’m thinking of placing PTFE tape around all the needle threads to stop air leaking in.

Video posted now as promised 

 

 

 

[Paul De Tourtoulon]

I put a piece of 2mm x 5mm silicone tube on my needle valves it stops them turning and reduces air leaks.

[Martin McIntosh]

PTFE is unlikely to work. Even OS fitted tubing on their 26fs.

[cymaz]

I’ve not been idle. Still working on the test stand, now modified again! I figure it’s easier to experiment with this and then build in what works into the airframe.

I’ve dropped the tank about an 1” and installed a uniflow tank set up. There is little or no syphoning from the tank into the carb and the engine seems more even in the runs. I will do it with another tank/ engine just to see if I can repeat the results....