Topic: 1/3 Scale Bristol F2b Fighter

BTW not much to report as lately we have had company over and so not much time in the shop

The Bristol Fighter is one of those designs which is a magnificent model subject. A straightforward practical layout with scope for massive detail, both internal and external. Over the years I have come to know the f2b in great detail, having photographed three of them in intimate detail (Hendon, Duxford and Old Warden) and having designed a half-built 3.5:1 scale model, started over 20 years ago (raising a family and house renovations getting in the way...).

One thing I have noticed about the F2b is that it shares a characteristic with several other classic aircraft, the fact that in a number of areas it isn't actually the shape that people generally think it is. I would like to share with you one of the F2b's shape quirks, the upper cowling panels:

The upper aluminium cowlings comprise three parts. From the radiator cowl to the front centre-section struts is a parabolic curved cowl which follows the cross-section of the radiator surround, no problems so far. Behind this comes the skin of the gravity petrol tank. At the front the tank has the same cross-section as the cowling ahead of it, but at the rear of the tank the shape has changed considerably. Where the tank connects to the front cockpit fairings the shape has become a sharp curve at the top with straight-tapered sides leading to another sharp curve to straight vertical sides at the bottom. The straight tapered sides continue back to the front cockpit. This was done to improve the forward view for the pilot. The sudden change in cross-section means that the petrol tank sides have substantial compound curves in them.

The photograph below is the Imperial War Museum's F2b at Duxford. This example illustrates the shape change well as the petrol tank is painted a darker shade of grey than the other aluminium panels. It may be seen that the join between the engine cowling and tank is a continuous curve, while the tank to cockpit fairing joint shows the flat sides.

Hopefully this will be of some use to those contemplating building an F2b. Below the Duxford picture I have included a few of my part-built model.

Today my Press Brake arrived from Micro mark will get some photos of it and fittings soon. I have been prepping up some fittings and getting things organized for the next stage of the build so I can do like the first part and keep going without stopping until this phase (the fittings and internal wires) phase is done like I did on the framing phase.

 

Martin..... Jim Lambert here, I remember your models with considerable awe, do you remember the fly-in at Dundee in about 1985, I think you brought the part completed Bristol up to that !! wonderfull... You must get it completed and get flying again soon, it is a masterwork.......
          Best Wishes ... Jim lambert

Martin..... Jim Lambert here, I remember your models with considerable awe, do you remember the fly-in at Dundee in about 1985, I think you brought the part completed Bristol up to that !! wonderfull... You must get it completed and get flying again soon, it is a masterwork.......
          Best Wishes ... Jim lambert

Hi Jim, good to hear from you.

I remember the Dundee trip, I think it is the furthest one-day round trip I have ever done to a flying event...

back then I had the Bristol M1b and 1/3 Gipsy Moth. I didn't start building the F2b until December 1987 - should have finished it years ago but I just don't get the opportunity to get stuck into it.

Martin.

Martin, any chance of some details on the fuselage bracing (maybe in a dedicated thread )?   Some close ups and info on materials used would be much appreciated.   

TIA

Alan

Martin, any chance of some details on the fuselage bracing (maybe in a dedicated thread )?   Some close ups and info on materials used would be much appreciated.   

TIA

Alan

I'll see what I can do - may take a while though. Model will need a good dusting...

lol im getting there guys trying to finish up stewys Pfalz Drawings today so he can get going on that one

Looking absolutely fantastic (wheres the drooling jealous smiley) question from a total ignoramous - how did you join/joint the aluminium tubing for the tail feathers

a friend of mine made a jig and tig welded the tail feathers together. but there is a product out there called metl weld spelled just like that that is an epoxy exspecially made for high stress joining of metals. they use it in the high performance racing boats

here are some not so great pics of my fittings and my brand new metal press from micromark which cost me $29

the fingered part is already laminated with a piece of 3/32 balsa in between the 2 metal parts to give it some thickness.

I put the duro spray glue can in there to give some size ref to some parts

Ok I got my fittings pretty much cleaned up and painted here is a series of pics of the fittings so far. Once they are all on I have to add the 1/32 music wire bracing as the full scale used solid wire rod rather than braided cables. sorry for quality of some pics I wasnt using my tripod and was trying to get some close up shots.

note to steve FB 15 I show double bend lines. it should just have one in the middle and bend it at 90 deg to go down the side and across top.

the screws in the pic are pan head sheet metal screws  #2 x 3/16" I think it should be  the next size smaller which I guess is a #1 screw. the length is perfect.

also not shown on the plan is location of FB 22 they are bent at 90 deg and go on the insides of the 1/4 sq uprights and cross members

Thanks Joe, just a thought but is it worth staining the woodwork before the fittings go on?

Steve

yes its definitely worth it. I wasn't going to really do any staining but in the cockpit area on this one. also if you stain the whole plane don't forget to stain the belly runners before you put them on. I don't have mine in place yet because of a few wire bracings to do. that's something else I haven't drawn on the plans I need to add. I forgot to draw the series of belly runners that run the length of the bottom of the fuse

Hey Prof!,
I have a numpty question but it's buggin me
What does that press thing do? how did you make all those fittings?

Cheers
Mudders

ok there are 2 different slots in the bottom of the press. depending on thickness of metal you flip the square stock around to the slot you need. then you insert your metal fitting. the top peice has a dull V shaped blade on it. you turn the knobs on the top and that drives the "V" blade down onto your part and presses it into the slot causeing the part to bend. the further you press it down the more the angle. so it can go from flat to a sharp V shape depending on how much you turn knob.

I will take some pics of the steps parts

Arr I see 

So all those metal parts, made by hand? Dremel, waterjet/laser thingy

I drew up all the parts and then sent them off to jaime who arranged them and sent them down the street to a waterjet company that cut the sheets for him.


I just did a nice series of pics to make the landing skid bracket will resize and post them shortly

Thanks Prof,
I had visions of you frantically filing and hacksawing
Nice work

Thanks Prof,
I had visions of you frantically filing and hacksawing
Nice work

mmmm who can do this in the uk, i have a number of fittings for the d12 that would benefit from this

Ok here ya go. since I was asked about how the bending machine works I  used the best example I had for a fitting and that is the fitting for the Landing skid as it forms a box.






















PS stewy might check with jaime and see if he has any if not he probably will by the time I am totally done with all the drawings. since it will just be a small thing he could probably just ship it to you in an envelope and you wont need to worry abt all the customs etc stuff  but i am just guessing

Hey guys Well today I been working on my bracing wires. I made those little coiled Ferrules. its a pain I made a little setup and coiled a bunch of wire around a 2-56 pushrod which was a perfect size.
 
So with out further adoo Here is a closeup of one of them I found a pic  that wasnt the greatest but it looked like there were 5 coils to a ferrule thingy so thats what I made them

I am using 1/32 wire for my cross braces. So I found out that if I use a 2-56 rod to coil my wire it will fit in there nice and tight inside the coil
 
I start by chucking up my 2-56 rod and some of that Jewelry wire you get from some place like Michaels or Joann Fabrics. It is copper wire with nickel plating or something.

Next I drill a small hole barely big enough for the rod in a peice of scrap wood and slide it onto the rod
 

Next I fire up the drill and start Coiling. As I coil I keep the board against the coil which keeps it tight together.
 
After I get my coil together I look at it under my magnafying glass light and using my xacto I count off 5 coils and spread it apart at the end of each 5 count. then I just come back and smip them off and throw into a container

1 side done sorta






The way it looks in the pics is just like it looks on the full scale.

Now for the purest out there there is only 1 small variation from the full scale and my model. the bracing wires with the ferrules are on the inside of the fuse framing. those solid wires on the outside are attached with fittings like you see on a ball link end. But the only ones I could find were plastic which looked like Carp. and the way I am doing it here at least was used on the full scale bristol just on the inside of the framework.

Nice work Joe, I'm going to gaze lovingly at this during today. 

still gazing Joe, fine job too.

One thing I am confused about, is won't the brackets and cross braces show through the covering?

You know now that you mention it I can see what you mean. A very interesting and if I might say so an original observation.I am surprised i didnt notice it sooner Ken

I would have thought that the X brace locating brackets would have been on the inside face of the structure, Just a thought now that you have brought it to my attention.Could be wrong of course but there again....................Regards Ken

looks like the full size has the same bracketry but also a piece of combing to fair the covering in.

I can see that now, The combing must run the entire length of the A/C both upper and lower longerons.Of nessesity being deeper in section than the ferrule of the X bracing. The big difference being that on the model the covering is fixed on with adhesive whereas on the full size the covering is laced on and in consequence would not be as taught , certainly not drum tight as is the case with model practice. Ok, I can go with this now it has been explained. My apologies to our Joe for doubting him, but it does show people take notice and only by asking questions do we learn.My regards to you all, Ken 

I can see that now, The combing must run the entire length of the A/C both upper and lower longerons.Of nessesity being deeper in section than the ferrule of the X bracing. The big difference being that on the model the covering is fixed on with adhesive whereas on the full size the covering is laced on and in consequence would not be as taught , certainly not drum tight as is the case with model practice. Ok, I can go with this now it has been explained. My apologies to our Joe for doubting him, but it does show people take notice and only by asking questions do we learn.My regards to you all, Ken 

aye ken, we love and learn...

thanks shaun...

Haha you dare doubt the Looney shame on you guys rofl. Yes there are several short stubby boards fixed to the outside of the longerons and then has what I call a batter board outside of it. the only thing I dont have pics of that I will have to guess on, is how the boards faire into the cockpit section. I assume in that area it is just double boarded as the metal peices  for that area look like they just attached to the longerons. I would assume there are some boards doubling that area so that the metal sections are flush with the rest of the sides

I found my closeup of the ferrule for full size. this is from a Bristol Boxkite that is being built