Barnstormer Boys

[jolliffee]

Posted by Martian on 19/10/2013 17:52:56:

Still undecided as to which Barnstormer pref it will be one the will fly on 3s batts cos thats what i have

I'm going to use two 3S in series to give me a total of 6s that way I still have flexibility and it helps to keep the costs down.

[Dave Miller]

Posted by jolliffee on 01/12/2013 14:42:40:

Posted by Martian on 19/10/2013 17:52:56:

Still undecided as to which Barnstormer pref it will be one the will fly on 3s batts cos thats what i have

I'm going to use two 3S in series to give me a total of 6s that way I still have flexibility and it helps to keep the costs down.

That's what I'm fitting to mine; it also makes the physical installation easier.

[Andy Green]

Just getting all the stuff together to start my 72" build. I'll be adding ailerons, where and how as yet to be decided, but it raises the question as to where to run the servo wires (there will be a servo in each wing half.

I'm thinking I can use the cabane struts, if I cut each in half with a small gap that gives me 4 isolated sections. That's a +ve & -ve feed both servos can share these and 2 signal feeds.

All I'd need to do is wire from the receiver to the cabanes and have a suitable pick up in the wing to pick up the signals and supply to each servo.

Can anyone see a problem with this?

Andy

[Dave Miller]

Posted by Andy Green on 05/12/2013 11:15:34:

Just getting all the stuff together to start my 72" build. I'll be adding ailerons, where and how as yet to be decided, but it raises the question as to where to run the servo wires (there will be a servo in each wing half.

I'm thinking I can use the cabane struts, if I cut each in half with a small gap that gives me 4 isolated sections. That's a +ve & -ve feed both servos can share these and 2 signal feeds.

All I'd need to do is wire from the receiver to the cabanes and have a suitable pick up in the wing to pick up the signals and supply to each servo.

Can anyone see a problem with this?

Andy

There should not be a problem as far as I can see, you obviously have to ensure good connections but that is a mechanical issue.

[Andy Green]

Yes - I'd use proper solder tags for the internal connection, it's the strut to wing connection I'm worried about. Thinking I'll add a large washer to the wing, and a light vaselene grease should keep it clean.

Sounds like a plan. And for anyone not in the know the ailerons work by magic.

Andy

[Phil Winks]

Hi Andy that sounds like ? plan though you would be introducing a weak point by splitting the cabanes so the mounting block needs to be good and firm otherwise I can't see why not

Phil

[kc]

I would think heat shrink the servo extension leads to the cabane structure or even the wing struts would be easier & safer. Just needs a recess to hide the plug & socket in the wing underside.

[jolliffee]

Umm! Interesting but I think I will stay with a wired solution, though I don't want them to be flapping in the breeze so some sort of cover and paint will be needed.. maybe I'll use a single s.bus cable??

Edited By jolliffee on 05/12/2013 14:11:06

[thunderstreak.keith]

Hi barmystormers, Don`t know iff this will help anyone out but I have a copy of RCM+E 1971 with a write up of building a reduced version of D Boddos barney. It was a single job @ 39" span for .049 - .060. I also have the list of balsa etc reqd for that build. I could post it on yer iff that is allowed, (not sure about copyright rules after reading all previous) wont start that again though Let me know pls. not sure iff anyone is building this version. I should have a plan myself somewhere, something I didnt get around to building,

cheers keith

[Phil Winks]

Hi Thunderstreak I can't see any issues with copyright when it comes to posting anything from previous issues of the magazine though posting the plan itself may be one I'm sure a private message to David Ashby would clarify this for you. and I'm sure this info will be of use to those building this size

Phil

[Tony Bennett]

well i am still waiting to order some servo's for mine before i can finish it, but money is tight at the moment.

i expect i won't get it flying till after christmas now.

[thunderstreak.keith]

Thanks phil, havnt actually found the plan yet, but anyway my knowledge of scanning something that size is beyond me, i can go so far as A4 and thats my lot on a computer, can just about post fotos on yer. wasnt intending to do that so thats ok. it was just the article may be useful thats all. tis the size i will be building but not with a push button and escapement th/elev/rudder maybe aileron with mini gear. will have a look when i dig out that plan

keith

[David Davis]

I have been very busy doing up my house recently but I'm giving myself three or four days to build the 39" Baby Barnstormer later in the month. Mine will have rudder elevator and throttle control and be powered by a Mills 75.

[Dave Miller]

I must either get a bigger workshop or make smaller models for I had to take this one into our house to assemble it for the first time and whilst it’s a bit late but I thought that I should post a few more details of my attempt at a Barnstormer.

As I said in an earlier post I increased the span by and extra bay each side which has taken the wing span to 92 ½ inches(2.35m) instead of 88 inches. This was to help counter the extra weight of the power and sound system but I doubt that its effect will be noticeable in flight, the take-off weight is 12lb 11oz (5.75kg). Since the cord is a constant 14 inches the area works out at 1295 sqins less a bit for the wing tip shape, say 1250 which gives a wing loading of about 23.4oz/sqft which is a bit higher than I’m used to but I think OK for this type of model.

Covering film is from Hobby King, which whilst selected on cost grounds I am very pleased with; pity their stocks are so low which limited colour choice.

I was guided in motor selection by Purple Power’s recommendation and installed their PPPO-5065-380 which is rated at 1820w and 380kv. The initial flights will be on a JXF 17x10 propeller that I also brought from them. I’ve used 2 x 6000mAh LiPo batteries rather than the 5000 recommended since I was originally going to power the radio and sound system from them but subsequently decided to fit separate batteries to each as I thought I would need more nose weight; hence all the batteries. I have used a XT90 connector plug and socket as a shorting (kill) plug; it can be seen between the two switches in front of the battery packs. The model balances just behind the recommended point but is still in a very conservative position – I hope.

The Model Sounds system that we discussed in an earlier thread works well, it’s very loud indoors but don’t suppose that will be so apparent outside. I am using the SE5a sound file since that is close to the sort of engine that this type of aircraft may have had; alright it’s over the top and I should have used the J3-Cub, but it sounds nice and racy; I'm sure D.B would approve.

[Dave Miller]

I've up-loaded a few pictures to an album HERE. When I find out how I shall add a few more

[thunderstreak.keith]

Right found the plan. These might help a few out, I`m starting to get all my bits together now. This info is for the "barnstormer Baby" 39 " version. David M, Iff you read the first bit one of the originals was a whopping 98" span, could you extend out that far and thereby take the wing loading down a tad? just a thought

[thunderstreak.keith]

Thought the above may be of some help. Dave M, just a thought but you mentioned the W/L on your 92 1/2" span might be a tad high for you. Reading the above article there was a 96" version boddo did. couldn`t you extend that bit further and bring it down a bit more? not telling you how to suck eggs just trying to be helpful.

[jolliffee]

Posted by Dave Miller on 10/12/2013 11:49:58:

I've up-loaded a few pictures to an album HERE. When I find out how I shall add a few more

Great pictures Dave, I hope you don't mind if I ask few questions that will help with my build; I was wondering how the wings were held on, and how have you hidden the servo wires to the wings.

Thanks..

[Dave Miller]

Posted by thunderstreak.keith on 10/12/2013 14:49:07:

Thought the above may be of some help. Dave M, just a thought but you mentioned the W/L on your 92 1/2" span might be a tad high for you. Reading the above article there was a 96" version boddo did. couldn`t you extend that bit further and bring it down a bit more? not telling you how to suck eggs just trying to be helpful.

I could have done but I suspect that the fuselage would also need extending a little too to maintain the models proportions. I'm not saying the wing loading is too high just that it is higher than I'm used to flying.

[Dave Miller]

Posted by jolliffee on 10/12/2013 14:58:54:

Posted by Dave Miller on 10/12/2013 11:49:58:

I've up-loaded a few pictures to an album HERE. When I find out how I shall add a few more

Great pictures Dave, I hope you don't mind if I ask few questions that will help with my build; I was wondering how the wings were held on, and how have you hidden the servo wires to the wings.

Thanks..

I have installed a 36 inch long aluminum tube wing joiner through the center section and into each wing at the main spar point. There is a stub 4mm diameter peg near the trailing edge to stop the wing rotating and two trace wire braces that run from a couple of lugs on the bottom of the fuselage, these can be seen on the first picture laying lose. I have a 3mm threaded point in the underside of each wind to which they attach. Whilst these also will take some flying load their primary purpose is to stop the wing wandering off down the tube during flight.

I have routed each of the two servo cables and the speaker cable up the front of of a cabane strut (one to a strut) and then covered all the struts with foil covered card to hide them from sight, it also gives a rounded edge to the struts. That was one of the reasons the I made a separate fixed centre section rather than the two piece wing shown on the plan.

By-the-way in case any one is interested I brought the wing logos from Model Marking who gave a very good service, and quick delivery at a very good price.

I hope that helps.

Edited By Dave Miller on 10/12/2013 16:02:40

Edited By Dave Miller on 10/12/2013 16:03:48

[Dave Miller]

I’ve finally got around to assembling the beast and running the engine on load for the first time.

With a JXF 17x10 propeller I got 7,150 rpm, I have no idea if that’s good or not but it did seem to be sucking quite well. Now all I need is a warmish dry day for the maiden flight.

[Martian]

lovely model Dave and super finish

[jolliffee]

Looks really great, if mine looks half as good I will be thrilled, and let's hope the weather is kind so you can get a maiden flight in soon. I'm going to use the same electrics as you have so I was wondering if you had measured the Watts and Amps?

[cymaz]

super model.......IT'S A 10 FROM LEN

[Dave Miller]

Posted by jolliffee on 15/12/2013 13:22:39:

Looks really great, if mine looks half as good I will be thrilled, and let's hope the weather is kind so you can get a maiden flight in soon. I'm going to use the same electrics as you have so I was wondering if you had measured the Watts and Amps?

Thanks all.

I didn't measure the current or watts as it started to rain here. I will do that later and post my findings.