Standard Beam Approach (SBA) Restoration Project

Looks authentic James

Don’t know if you got my email but we received the Inertia switch for which many thanks 🙂

John

Reproducing QA stamps

Hi

Someone suggested that I simply send a pic to a bespoke ‘stamp’ making company in order to restore authentic marking to equipment I had to paint.

To make it as economical as possible I kept the stamps I needed at the right distance but squeezed other markings onto the same stamp with the intention of just cutting the stamp to sepearte them out again.

Happily the stamp company supply a transparent item with a sticky backing – perfect!

Anyway here are the first trial impressions of the unseperated stamp. Suitably messy!

Cheers
James

Hi Tony

Yes, I have been through VMARS with a fine toothed comb! I’ve even been through the sacrilegious Practical Wireless article attached!

Always open to guidance on the location of anything SBA so thanks.

Cheers
James

James I don’t know if these guys can help out with any gaps you have, they do have loads of manuals already up online

http://www.vmars.org.uk/

may get to that bit James as we work our way through the Vol 3

Hi Andy

That all sounds right. It’s a pity that you can’t get a list of part numbers for the aircraft build itself as that would definitely list the seperate parts I would think. Though that gives me an idea! If you don’t hear from me again on the subject then assume it was a bad idea!

There would probably been a large number of Bowden cable lengths given that the Pilots control unit and the main receiver would have been at different distances in each aircraft. There are about 30 different electrical cables mentioned in the AP for as many different aircraft.

Later SBA kit had fully variable tuning so that type of flexible drive would also have had a number, although it was used on other radio gear.

Cheers
James

James,
I think it is probably reasonable to assume that 5B/1262 is the Stores Ref for the complete cable assembly.

I say this because the copy of Section 5B which I have, kindly provided by Dave ‘radarsdesk’ a while ago, whilst not including an entry for 5B/1262, under a general heading of SBA has a sub-heading “Controls, Remote, for use with Receivers R.1124A, R.1124B, No 28 Assembly”. This then has three entries, 5B/999, No. 2F, 5B/1261 No. 8 Type F, and 5B/1263, No.6F.

If we assume (dangerous, I accept) that these are different cable length assemblies, then 5B/1262 is probably a fourth length.

5X/1322 and 5X/1323 may then refer to the end assemblies without the connecting cables?

Andy

Hi Andy

It can get stranger – the pic attached has completely different numbers!

I can find any numbers for the Bowden parts – it doesn’t seem to figure in the APs

Cheers
James

James,
I associate both 5B and 5X with electrical items, so both rather odd on a mechanical assembly.
5B is Aircraft Wiring Assemblies, and typical things seem to be Conduits, Cable Assemblies and Junction Boxes.
5X is Components of Wiring Assemblies, and includes Plugs and Sockets, Terminal Blocks, Junction Boxes, and tools related to such things.
So strange! Have any of the AP’s for SBA that you’ve studied made reference to the Bowden Cable Assembly?
Andy

Hi Andy

Thinking a bit more about your question: “There are three Stores Reference Numbers there, 5B/1262, 5X/1322 and 5X/1323. Which parts do you believe they each refer”.

It seems that ‘B’ is assigned to cables and so I would guess that this refers to the Bowden ‘cables’. The SX numbers being sequential probably refer to the two mechanical assemblies.

Cheers
James

Hi Eddie

That’s good news, can you give an example of what an aluminium ‘print’ has cost you? The web sites all require you to request a quote. I’m just looking to see if it is going to be something I could consider or if it will require a lottery win!

Cheers
James

James, I believe that Shapeways have a plant in the Netherlands. So not all the way from the US!

As far as the 3D printed materials are concerned, I think the selective laser melted aluminium is probably the most useful for structural use. I’ve also made several patterns with the inexpensive white plastic materials and had them cast.

Hi Eddie

Not sure about getting stuff from the States but that site certainly is an eye opener! Where was I when 3D printing went from white plastic to Titanium and ceramic!? The material you suggest does look like just the job.

I am going to review what is on offer here now as I can think of a few things that would be good in Tintanium – could make new Breeze connectors!

Cheers
James

Hi Andy

Firstly – you have seen this guys site I hope:

http://aircraft-cockpits.com/ww2rafrefno.htm

I can’t help but I might guess that the X might be a ‘mmm, where could we put this thing’ letter so perhaps the code for the Bowden cable? It might be stamped on that part as there is no room on the cable?

Anyway, here’s one to add to your photographic record, not so wow but still part of the whole set! Its 10H/2638 the metal friction lock for the Pilots variable control knobs.

Cheers
James

Shapeways has an “Elasto-Plastic” material that you can get printed – I’d guess that might be a good material to make a rubber stamp out of. (I haven’t used it myself).
https://www.shapeways.com/materials/elasto-plastic

James,
There are three Stores Reference Numbers there, 5B/1262, 5X/1322 and 5X/1323. Which parts do you believe they each refer to, and is one for the complete assembly?
I’m building up a photographic record of items catalogued by Stores Reference, but I’m not sure what to do here!
Andy

Restoring is great but what gets lost often are the original ink ‘stamps’ as you repaint panels etc.. I considered for a millisecond carving another stamp from rubber but I now have a cunning plan……

I can easily transfer the shape of the stamp from a photo to a 3D model of a simple rectangular block. Next I can extrude the shape of the lettering and any graphics from the block. Make a 3D print and hey presto – a stamp! Cunningly all the stamp markings can be reproduced on one block so keeping all the juxtaposition correct. For no extra cost I can extrude guide parts such that the stamp would land in exactly the right place on the item too.

The stamp will be hard plastic and so not give a great print but the real stamps were never precisely done.

I want to try so has anyone out there got the URL of a good 3D printing service please? My first victim for repainting and re-stamping attached!

James

I did get to model the control handle though, just from photos – it even has an insert that fits but sadly it isn’t strong enough to grip the shaft tightly enough – but the real knob actually has a very sophisticated ‘grub’ screw that not only goes through the shaft of the switch but appears to be tapered to expand the split shaft too in order to promote even more grip!

This kit would probably be considered too complex a design today and certainly would be expensive!

Some pics attached

Cheers
Jamnes

Hi John

I’m not drawing the parts but happy to do so when you need them! Probably you may have procured a real one by then – would save you a lot of effort!

Here are a couple of pics of the internal workings to give you an idea of the task. The main issue would be the cast parts I suspect, but if you had a ‘3D Model-to mould-to-casting’ path set up it would be a lot easier.

I had originally planned a home made version using meccano gears since you can’t actually see the parts when fitted but only got a short way into the design before being donated the real thing!

Cheers
James

nice update James

Are you drawing some of these parts up as we’ll need the info to reproduce them for our cockpit?

John