john stones 1 - Moderator Posted February 14, 2014 Share Posted February 14, 2014 I agree, its just the way DB designed it don't mean you cant Tinker with it (sorry about the pun) Quote Link to comment Share on other sites More sharing options...
kc Posted February 14, 2014 Share Posted February 14, 2014 Thanks for your comments.As Danny's advice agrees with my instinct I may reduce the span by one bay or space the ribs closer. Be interesting to know if the Bistormer 60 had the same number of ribs as the 63. For me the idea is to produce a practical model that flys well rather than stick religously to the original plan. Something that looks scalish but does not need the perfection of a scale model.I dont think the Pitts style is appropriate for the Bistormer and certainly not the Barnstormer. More of a Luton Minor look or Westland Wizard style would suit a Barnstormer better.Whilst checking the Westland Wizard details I found the Boddington 60 inch Wizard plan from RCSQ Feb/March93. Guess what rib profile and size it has? Dead ringer for a Richtofen / Bistormer 60 /Barnstormer 63 rib with just different leading edge which is more like the Tyro /Tinker angled 1/4 sq. Which just goes to show how he produced so many designs. Anyone who remembers the Wizard free pull out plan will remember it as the one where they never published the wing plan next month as promised! Probably only the keen types like me wrote away for a copy. Anyway I still have the complete plan and article. Quote Link to comment Share on other sites More sharing options...
kevin b Posted February 14, 2014 Share Posted February 14, 2014 I've also got the Wizard plan and was only looking at it last weekend. It may make an appearance at some stage. If anyone wants a copy of the plan I have it stored digitally. Just pm me your e-mail address. kevinb. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Can any of you barnstormer builders let me see a pic of your fus I am interested in how the doublers are termonated behind the rear cockpit bulkhead its not clear on the Bistormer plan and may be the same on the barnstormer. I could adlib but thats not fair on the novice builders.CheersDanny Quote Link to comment Share on other sites More sharing options...
kc Posted February 15, 2014 Share Posted February 15, 2014 Boddington designs often don't have the doubler extended behind the bulkhead. The Richtofen and also 58 inch Tiger Moth stop at the bulkhead ( both bipes of course)However the Mark One ( a later version of the Barnstormer 63 ) has the 3/16 sides extended back in a triangle way beyond the rear cabane strut even though it's a parasol with no lower wing. Perhaps this later version is the result of experience with breakages on earlier designs? Quote Link to comment Share on other sites More sharing options...
Barnstormer 52 Posted February 15, 2014 Share Posted February 15, 2014 Hi I have plans for 52", a plan out of 63" kit, and 2 sheet plan for 72" and the 1 sheet plan from a 72" kit. None of these have a doubler aft of the rear cockpit bulkhead I'm afraid. I have never had a breakage in that area but it often struck me as a weak point. Maybe the Bi-Stormer has it due to the cut out for the lower wing? I you post a picture of the plan maybe someone could interpret? Regards Geoff Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Hi Geoff, the triangular section is the one I mean it ends at F8, but how? there is no clue. It must get blended in somehow. Must say information on this drawing has been very hit and miss. Not impressed, maybe I am just used to Brian Taylor... You can see the doubler at the top, it isn't reduced to a triangular section yet Cheers Danny Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted February 15, 2014 Share Posted February 15, 2014 Danny are there longerons to be added along the rear section of the same thickness as the doublers? If not then it looks like that simply wants blending down to meet the line of the rear framework. The doublers on the Barnstormer are fitted inside that box section so no way of drawing comparisons there. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Hi Phil, and thanks, there are some longerons along the outside of the rear section, midway down and lower, but no indication that one would abut the end of the the triangular stock. But the drawing leaves a lot to be desired, I will add the other longerons that I do know about and the bulkheads and see what remains. I was going to change quite a lot on the fus, but I think with hind sight I perhaps ought to make it vanilla, ie as DB would have wanted it. This may be more useful to those wishing to build one in the future. Some of the wood I have used is a little thinner, for example the fus doublers should be 6mm or 1/4" I have used 3/16" but I don't think that will make much difference. I have shortened the nose and removed all of the side and down thrust but I am converting it for electric. Cheers Danny Quote Link to comment Share on other sites More sharing options...
kevin b Posted February 15, 2014 Share Posted February 15, 2014 I look at a lot of model plans as part of my hobby (I restore them too). A considerable number of them can be interpreted in different ways, like many things in life (which is why lawyers make so much money !). This is why the experts, such as yourself are invited to take part in the build. So that mere mortals such as myself can benefit from your wisdom and be happy that you are here to stop us making a real mess of things. kevinb. Grovel dept. Quote Link to comment Share on other sites More sharing options...
Dave Miller Posted February 15, 2014 Share Posted February 15, 2014 Why are you removing the side and down thrust Danny? Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Hi Kevin, thanks for the vote of confidence mate, but I assure you I am not an expert as my fumbling around on this one shows. I think the reason this one is proviing so difficult is the plan references the parts of the kit. This is not a kit. When it says for example F27 it simply means strip wood 3/16 x 3/8. So if you had a proper plan you would get more info I think. Hi Dave, I find that with electric models the side and down thrust are not needed. I appreciate why they are built into a model, especially a free flight design. Cheers Danny Quote Link to comment Share on other sites More sharing options...
Dave Miller Posted February 15, 2014 Share Posted February 15, 2014 I can't let you get away with that answer Danny. What do you think is causing the different reaction between the ic engine and the electric motor? Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Hi Dave, I am not going to say any more other than I am happy to adjust the trim on my models depending on the speed and throttle settings. Besides which the aeroplane looks silly with the engine pointing at the ground. I can understand why it is built in to many models. Mick Reeves and Brian Taylor don't use any if the full size didn't and that's good enough for me. I may have to eat my words when it flies Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Perhaps we should continue this conversation over on the BiStormer thread? Cheers Danny Quote Link to comment Share on other sites More sharing options...
Dave Miller Posted February 15, 2014 Share Posted February 15, 2014 OK I can accept that, but it was your suggestion that electric power doesn't need thrust off-set whereas by implication ic does that I found confusing. Quote Link to comment Share on other sites More sharing options...
Barnstormer 52 Posted February 15, 2014 Share Posted February 15, 2014 Not casting any aspersions Does the propeller know what motive force is driving it around diesel - electric-glow Regards Geoff Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 Ahhh sorry Dave Quote Link to comment Share on other sites More sharing options...
Dave Miller Posted February 15, 2014 Share Posted February 15, 2014 Posted by Barnstormer 52 on 15/02/2014 19:24:27: Not casting any aspersions Does the propeller know what motive force is driving it around diesel - electric-glow Regards Geoff No it doesn't Geoff but they tend to use different diameters and pitch which may effect the required thrust lines; if that is any are required. Quote Link to comment Share on other sites More sharing options...
Dave Miller Posted February 15, 2014 Share Posted February 15, 2014 Posted by Danny Fenton on 15/02/2014 19:28:26: Ahhh sorry Dave You're forgiven; just this once mind. Quote Link to comment Share on other sites More sharing options...
Barnstormer 52 Posted February 15, 2014 Share Posted February 15, 2014 Purely as a discussion now. some one else with more aerodynamic knowledge than me, please chip in. Different pitch and diameter, - plus different rpm. "for every action there is an equal and opposite reaction" Surely the thrust to overcome the drag in order to fly an airframe is only going to come from the resistance against the blades of the prop, and therefore regardless of pitch or diameter, a certain amount of air has to be pushed backwards. and the force required to do that is going to be the same? Regards Geoff Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted February 15, 2014 Share Posted February 15, 2014 Hi Danny a word of warning on the side and down thrust being electric doesn't mean you can ignore it mate, just look at the tucano from last years build, Nigel hawes 45", that has enormous side thrust and mine flew straight and true with next to no trimming. Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted February 15, 2014 Share Posted February 15, 2014 Posted by Barnstormer 52 on 15/02/2014 20:15:08: Purely as a discussion now. some one else with more aerodynamic knowledge than me, please chip in. Different pitch and diameter, - plus different rpm. "for every action there is an equal and opposite reaction" Surely the thrust to overcome the drag in order to fly an airframe is only going to come from the resistance against the blades of the prop, and therefore regardless of pitch or diameter, a certain amount of air has to be pushed backwards. and the force required to do that is going to be the same? Regards Geoff Pretty much so Geoff however higher pitch props do work better at higher RPM and visa versa for the lower pitch props its all to do with efficiency and stall speeds of the prop, yes a prop can stall, however for a more detailed explanation you'd best look to someone with a tad more knowledge on this subject Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 15, 2014 Share Posted February 15, 2014 I feel that the time when side and down thrust have the most bearing is when the speed you ask the prop to deliver is disproportionate to the speed of the airframe. So when you bang the throttle open at takeoff, max throttle max torque little airspeed. I think good throttle management means that torque doesn't have such an effect. I was told a Puppeteer with a 24" prop turning at just over 2000 rpm wouldn't work, it did. Just my opinion mind you..... Cheers Danny Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted February 15, 2014 Share Posted February 15, 2014 It’s not just about torque ,you also have to consider the effects off spiral slipstream and gyroscopic precession that have varying affects through the various flight phases of speed/power settings Quote Link to comment Share on other sites More sharing options...
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