Jump to content

DB Mighty Barnstormer


EarlyBird
 Share

Recommended Posts

Two years ago, I bought the rib set, plans, cabane struts and U/C. Today I ordered the cut parts pack which weren't available two years ago. I am at the planning stage which will lead to a strip wood list then the build can start. My thinking is that this will be my 2024 main build.😊

  • Like 2
Link to comment
Share on other sites

Advert


3 minutes ago, EarlyBird said:

Two years ago, I bought the rib set, plans, cabane struts and U/C. Today I ordered the cut parts pack which weren't available two years ago. I am at the planning stage which will lead to a strip wood list then the build can start. My thinking is that this will be my 2024 main build.😊

 

Powered by ?

Link to comment
Share on other sites

Is this the DB Sport Scale plan and cut parts?   Seems a good buy for the ribs and also cut parts.

 

The Mighty Barnstormer was also published by RC Modeler in USA and is now on Outerzone to download.   the span is slightly different - maybe RCM rounded up and DB rounded down!    But the DB Sport one might be slightly different now as it is various owners could have changed things for production.   Whichever it should be a good model.  

Various other sizes of Barnstormer plans are available too - some on Outerzone (52, 29 &29 ) while others like 63 inch and 72 inch are from DB Sport & Scale.

Link to comment
Share on other sites

One thing I would advise before starting construction is to work out how to fit the wing bolts - from top or from underneath.     I have a Barnstormer 63 ( built by someone else )  and the wing bolts are inserted from underneath which needs a table or stand to get the wing bolts in.   And it's easy to crossthread from an awkward position.   If I had built the model I would have put the wing bolts in from the top and then it would sit on the ground and the bolts inserted downwards - much easier.   I would have tapped the dural cabane struts to take the wingbolt thread.   Once the struts have been drilled clearance size for the bolts it's too late to tap them!  

 

Note that taps are really quite cheap if you just need one size - perhaps M6 or 2BA - and only a taper tap is needed. Tracy Tools are good suppliers - an M6 tap will be hardly any dearer than buying 4 captive nuts which will no longer be needed.

  • Thanks 1
Link to comment
Share on other sites

11 hours ago, EarlyBird said:

Saito FG21 four stroke petrol. IC 😊

 

Steve

Steve, you might consider shortening the nose a little.

 

The original balanced with a 70's style .60 2 stroke engine which were pretty lightweight compared to your Saito FG21. (I averaged the weight of most typical engines from the period by checking reviews at the usual websites)

 

I did the calculations for fitting a Saito FA-100T to my DB short kit and came up with the conclusion that about 20mm reduction in the distance from the CG to the front former would be required to avoid adding lead to the rear end (even after servo's and flight battery moved aft a bit.

 

My rudder and elevators are also built-up (as opposed to sheet) with pull-pull controls so already lighter at the rear end.

 

The Mighty Barnstormer is a great design, best of luck with your build.

 

* Chris *

 

  • Thanks 2
Link to comment
Share on other sites

I did a DB S&S Barnstormer 63 two years ago. Not a difficult build but still ‘fondly’ remember the 33 bits of balsa that went into the built up tailplane!

 I Electrified it, reduced the dihedral (as per instructions) by 50% and added ailerons across the 4 outer bays in each wing.

Very stable, flys smoothly on 1/3 throttle (200W), loops effortlessly on 450W. At 100ft, get the power right, two clicks of aileron and you can put the tx down and have a drink watching it gently fly around in 200ft circles. On a light wind day you can choose which wheel to land it on!

 

Enjoy the build and flying it, it’s sturdy and has presence.

 

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Studying the plan shows I have most wood in stock except the 5/16" square balsa so the good news is that I can't add to my pile of wings from unfinished projects.

I am thinking of making a three-part flat wing. The middle part being across and permanently fixed to the cabane struts.🤔🤔🤔🤔

 

Steve

Link to comment
Share on other sites

4 hours ago, J D 8 said:

A bit like my Bristol, carbon tubes slide into tubes in center sections and wings. A single screw goes through a plate fitted to each wing into a nut on a plate in the center section.

That's exactly how I thought.

Will no dihedral (flat wing) cause a problem, second thoughts creeping in?

 

Steve

Link to comment
Share on other sites

Steve,

I'd advise building the wing as it was designed by David Boddington. A flat wing will not only look less pretty it will have no lateral stability. It simply won't fly as nicely, tending to wallow all the time and needing constant aileron (and rudder) correction.

When completed, If the cg is a bit forward, it will add to pitch stability which will help with the easy flying characteristics, you may just need a little more 'up' elevator range.

Looking forward to seeing this one.......     

  • Thanks 1
Link to comment
Share on other sites

3 hours ago, John Rickett 102 said:

Steve,

I'd advise building the wing as it was designed by David Boddington. A flat wing will not only look less pretty it will have no lateral stability. It simply won't fly as nicely, tending to wallow all the time and needing constant aileron (and rudder) correction.

When completed, If the cg is a bit forward, it will add to pitch stability which will help with the easy flying characteristics, you may just need a little more 'up' elevator range.

Looking forward to seeing this one.......     

Thanks John,

I was being lazy and looking for quick assembly at the field.

I am in favour of easy flying that's why this topic is in Trainer kits. 

 

I need to order some four-foot lengths of wood just to cut down on the number of splice joints, not that I am lazy BTW🤣

 

 

Edited by EarlyBird
Link to comment
Share on other sites

After studying the plans, I have ordered some wood. This exercise brought some questions in my mind, so I searched online for some previous builds, unfortunately this only increased the number of questions. No rush though as I am 'crossing bridges' that are miles away.

 

I have to finish Rhapsody, Peggy Sue II and keep ahead of @bodgerep (John) with The Ohmen.

 

Plenty to do!

 

Steve

 

 

Link to comment
Share on other sites

Steve, you'll find that many of DB's designs followed the same style of construction. I recently completed a DB Sea Stormer (see below), which is basically a low wing version of the 72" Barnstormer modified to look like a Schneider Trophy aircraft of the early 30's, and I would imagine the Mighty Barnstormer is very similar in terms of its major construction points. Ask away if you have any questions.

 

It is also interesting to note that the rear fuselage construction of the DB Auster is very similar, as shown by Danny Fenton's build log a couple of years ago, and I would expect other parts of the model to be similarly-designed.

 

 

PXL_20230908_102114048.jpg

  • Like 3
Link to comment
Share on other sites

16 hours ago, Nick Cripps said:

Steve, you'll find that many of DB's designs followed the same style of construction.

I had the sane thought Nick while I was looking at the fuselage it's a bigger version of the Mini Super. Which made me check the wing incidence and downthrust. Incidence I calculated to +3.8 degrees and downthrust 3.5 degrees.

 

If I changed downthrust to 0 and incidence to +0.3, or any combination, what would be the effect and why?

 

Steve

Link to comment
Share on other sites

3 hours ago, EarlyBird said:

I had the sane thought Nick while I was looking at the fuselage it's a bigger version of the Mini Super. Which made me check the wing incidence and downthrust. Incidence I calculated to +3.8 degrees and downthrust 3.5 degrees.

 

If I changed downthrust to 0 and incidence to +0.3, or any combination, what would be the effect and why?

 

Steve

Why would you want to do that? As has been said many times, DB's designs fly very well. Deviate from the plan, expect poor results...

Link to comment
Share on other sites

If you change the incidence the model will adopt a different 'sit' in the air to achieve the correct angle of attack for the flying speed - decrease incidence and the model will sit tail down.

With the wing being quite a bit higher than the thrust line on this design there is a strong drag/thrust couple ie, an up pitch tendency due to the drag of the wing. 

Mr Boddington knew what he was doing!

Edited by John Rickett 102
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...