Castings Vs Forgings

Forget casting, as mentioned above…..more problems than it’s worth.
A hand forging is a good way forward, at least you will get some of the grainflow going in the right directions.
If you have them hogged out from solid billet, you may want a stress engineer to do some calculations for you, as the dimensions may need beefing up a bit to take account of the grain being wrong. They will be slightly heavier but I don’t suppose that matters to you.
And, somebody somewhere must already be making this stuff.
Send me the part numbers and I will ask my local Spitfire builder (No joke)

Thanks Phantom…Now to see the bank manager to see whats in the kitty..
cheers

Talking undercarriage QldSpitty dont know whether this would be of any use to you

http://www.skysportengineering.co.uk/for_sale.htm

Skysport have Spitfire undercarriage up locks for sale at the moment “probably servicable”. Unsure what that would mean but…………………..may or may not be of int.

Trivia time…….

http://www.thefreedictionary.com/pintle

Middle English pintel,

penis, (from Old English)

So now you know 😉

Thanks for posting those drawings. My Spitfire knowledge is lacking but I love an engineering problem.

Next silly question…..what is the ‘pintle’ for? Is it the pivot at the top of the undercarriage leg around which it retracts?

It looks hollow from the drawing, to save weight no doubt, but is that the only reason? The suggestion that you could ‘put a plug of aluminium inside to strengthen them’ must mean you could machine a stronger one that was not hollow (if weight wasn’t an issue).

Shims maybe..That rings a bell…Pintles and landing locks are a rare commodity here in Auss I think.Ones who have them hang onto them for dear life.

The mkV pintles were much the same as mkI’s, but the journal size increased by 1/8″, making them stronger; I was under the impression that the angle remained the same, (through out marks I to XVI) and the increase in rake was achieved by angled plates, of course I could be wrong….

Cheers guys

Food for thought.Thank you for your wisdom as usual all….being a MkV the pintle would be an early one.Not sure where they changed the angle,either at the forging,the block or the wing structure.More homework needed there but I think the lock mechanism stayed the same.
The wing centre section stub spars we are machining out of solid and that only leaves smaller castings (I hope!!!).Bellcranks will have to be machined out of solid as well or cast.
Here are the items..

What do ‘pintles’ and ‘landing leg locks’ look like? I’d love to see a drawing or a photo.

If you are only ground running an aircraft the loads on critical undercarriage components will surely only be a fraction of the design loads (plus a safety factor) of, say, a heavy landing. Components, machined-from-solid, in a good modern high strength steel should be more than adequate.

Cast anything isn’t going to be as strong as forged, if your Spit is going to be a ground runner, then putting inferior cast components on the under carriage, is at the very least false economy, as has been seen recently, these A/C are prone to ground handling problems, and the last thing you want is to lose all of your prop blades with an U/C collapse.

Pintles that are no longer airworthy do come up, and if you are concerned with using them (even after NDT) you could always put a “plug” of aluminium inside to help strengthen them, the locks are less easily aquired, (especially the wing mounted part), I would suggest an “over engineered” replacement, from a less exotic type of metal, would be the way to go.

Go with the original design. In the case of the pintle you would not get the grain flow unless you use a forging. We have had new ones machined from hand forged billets that worked very well and were not that expensive. The drawings are available. The cost is in the machining but there are solutions to that.

Looking back on manufacturing processes during the war and metalurgy that the British had during the war.Would todays metals and processes be equilivent if you changed the technique used.With the Spit there are a considerable amount of forgings used on a the larger structures,pintles,landing leg locks etc and was wondering if newer metals used in castings or from being milled out of a solid lump being just as strong,if not stronger.Just looking for options at the moment for our project.

castings are a tricky business, especailly aluminium, all sorts of probllems can arise, from porsity, cold Lap, Lamiler indications, Heat sinking,

it would be better to get it milled out of new stock, but i would say it certainly would want Ultrasnic NDT before and after the item is made, also a flourescent DPI test,;)