My FE2b reproduction..

[John McKenzie]

[John McKenzie]

[Machinbird]

Wonderful work John.
Did you generally have examples to look at, engineering drawings, or just pictures to start from?
On the Bowden levers, did you hack it out of a piece of flat stock and then machine, or did you weld a piece for the handle onto a circular piece and then shape to suit? (On the latter method I would think you would be fighting weld porosity, but it could be done.) I suppose you could also forge a piece to near net shape using a suitable pattern. Anyway, I'm very interested in your approach to making parts like these.
Sid

[John McKenzie]

Hi Sid , Thanks for that ,..With regard to the " standard " levers , which have the two cables , : For these I had the loan of an original example from the late Philip Kraus , and from this I made some drawings .These three items were made from Mild steel billets , 2 1/2 " X 1" and cut out by my usual antiquated methods, by hand chain and drilling , hack saw and file, with machineing where possible on lathe and (borrowed/use of ) mill...To save on repeating etc ( can't do the "quote bit "yet ), I gave a fuller account on this in " My Be2b Reproduction " thread ,(sorry , haven't sorted out "linking" yet ).....See post #61 to 66 for this .As for the " Ratchet type" ..single pull lever , this was made in the same time honoured way as above ...However , for this one I had very little to go on . There was a description in the spares listings of a Bowden39? (or whatever ) " with circular mounting plate ".., but I couldn't find anything on this ... Of course , RAFmuseum were as helpfull as usual ,(ie...not at all !) .The drawings showed that something fitted to a block on the upper RH longeron , (its position turned out , on drawing up a GA , to be an impossible location ) , and another plan GA of the rear part , to do with the shutters , drew me to conclude that it must be a single pull type , (obviously ) as there was only One cable !....I found an illustration of a ( presumably ) similar type in the partial Bowder catalogue that I had a copy of ,with a ratchet and detent , and used this as a basis from which to make up my working drawings useing the typical internal measurements as on the Std lever ...The " pull " of the cable did , however have to tie in with the travel of the rad. shutter ,and the maximum posible travel in terms of degrees movement , of the ratchet lever from "open " to "closed ".The lever did of course , have, at all times to be "practical " in its opperation and* movements of lever and thumb opperated detent* . Also, it had to* be clear of fouling other things in close proximity ....A bit of a "juggeling " act here !.On disengagement of detent , the lever is assisted and helped in its "opening action" by the air flow against the shutters,( and also springs which are necessary when the machine is stationary on the ground )and is pulled back ,to close by the pilot to any position chosen, where , on re-engagement of the detent , the lever position is held.(against the air preasure )..Thus it is a " One handed opperation ".Best regards John.

[Machinbird]

Thank you for that detailed answer John. I knew that you were chain drilling and then shaping from your other postings, but I was wondering if you had other techniques as well other than raw application of perspiration. I see that you are doing considerable reverse engineering as well. The details on that racheting Bowden lever are far beyond what would be visible in a catalog illustration.

Do you ever have to harden parts? I would imagine that since these are non-flying replicas, durability isn't such a big issue and thus, mild steel is not a problem.
Truly inspired work.
Best Regards,
Sid

[John McKenzie]

Hi Sid , Yes , your observations on the reverse engineering bit would never have been noticed by the accountant types that I had to deal with .Apart from a few small parts that ,to be honest , I can't recall right now ,and springs of course , I don't think there was anything that specified heat treatement ( Ally' castings apart ) of any sort ...On the Be , I did have the axil area where the wheel bearings run (bronze ) HARD Chrome plated, but it wasn't nacessary ...On the FE , I could not get the 90 ton* Ni Ch Steel tube (RAF Spec 43 ) of ,08" wall for the axil , but I did get some ( T60) tube which is not too far off , and just upped the wall thickness....This machine weighs about one Ton (literaly ) if I remember correctly .!Most of the highly stressed parts are in S96 ( Ni Ch ) steel in the normalized condition and fittings are mostly MS or from medium carbon steel without heat treatement ....I did keep as close as it was possible to the original specs. and whether to fly or not made no difference ....my decision entirely ...I remember , in one letter from (D.Lawrence ), RAFM tried to get me to do things like leaving out baffles in petrol tanks on the reasoning that they would not show in order to save money ! ...However I took no notice of such abserdities ...Btw , I was not able to determine the material of the borrowed Bowden lever , but doubt it would have been much better than MS , though undoubtedly a forging ..beyond my capacity for just these three., bearing in mind that I had no knowledge of internet outlets if any ...Regargs ...John

[John McKenzie]

With respect to the condition of the " original nacelle "...as seen in the photos ,;Much to my dis-approval , It was a directive of the RAF museum that no work was to be done on this original (sic) component .... Orders from" On-high "...supposedly in order to preserve the " Patina "..and also , which was nearer to the truth ..They didn't want to spend any more money on it ..(RAFM).....A wholely flawed decision as was inevitably later proved .

Now back to the details.

[John McKenzie]

Air preasure from either mechanical or hand pump , supplies air through 2 selectors and a relief valve , to the main or auxhilary petrol tanks . From here , petrol is sent , via 2 selectors , either directly ,or via the service tank , to the engine carburettor ......See previous posts for a more detailed explanation of the whole system ...JM

[John McKenzie]

[John McKenzie]