Split Axles Current Collection
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Dog Star
Western Thunderer
Want to check that the company will take some to the event?Ill have a couple of metres
I note from the web site that the rod is available in different lengths - any one any preference? (noting that any sent by post is likely to be cut into approx 12" lengths).
regards, Graham
JimG
Western Thunderer
Richard,
If you've got problems getting some rod, I'll be popping down to Al's Hobbies in Bristol to pick some up for myself and could get some for you at the same time
http://alshobbies.com/shop/cat.php?id=1023
Jim.
Steph Dale
Western Thunderer
Jim,
Carbon (fibre) rod wouldn't be fantastically useful for this job as it tends to conduct electricity...
Bristol Kite shop is on Cotham Hill - so it's also on the north side of Bristol. They're the guys I bought my GRP rod from: http://www.kitestore.co.uk/
Steph
JimG
Western Thunderer
That I didn't know. I knew carbon rod does - like in my RSU
- but I somehow considered carbon fibre rod to be an insulator.I know the kite shop well - I had my business premises just down the road some years ago. I will probably have to take grandson into Bristol one of these days in my family taxi driver guise
so could go via Cotham Hill and have a look.Jim.
Steph Dale
Western Thunderer
That I didn't know. I knew carbon rod does - like in my RSU
Jim.
He he - for some reason it's not common knowledge, but effectively carbon fibre is graphite; so yes it's conductive. I've actually got a set of hi-fi cables here made from carbon fibre; out of use though as although they work, they sound b****y awful.
Steph
JimG
Western Thunderer
I'm just trying to imagine my language as I put a meter across a completed axle - as the truth dawned.
Of course, I would never have checked out the carbon fibre with a meter before making an axle. Jim.
adrian
Flying Squad
It might be an apocryphal story, but a good friend of my Dad's use to work at Ciba-Geigy at Duxford where they were early developers of carbon-fibre pre-preg material. Such that I had a day touring the factory in the mid 80's. Amongst the many stories he had was one where they caused an electrical blackout over part of Cambridge. As it was early days the filtration system wasn't brilliant and quite a few stray carbon fibres escaped, quite light they floated in the air like dandelion seeds. Given the number vented to atmosphere more than a few ended up at a local sub-station where due to their conductivity they unfortunately shorted a couple of cables and tripped out the electric for part of Cambridge!
The conductivity of carbon fibre also causes big problems in aerospace, lightning strike protection on carbon fibre composite wings needs a lot more careful design than the traditional aluminium alloy construction.
Dog Star
Western Thunderer
I wonder if Uncle Bernie has considered the interesting effects of racing F1 tubs in a thunderstorm?
daifly
Western Thunderer
Is it any more of a problem than driving your highly conductive motor car? Having been struck by lightning countless times whilst at work over the past 40-odd years, apart from a bit of scorched paint and the odd rivet head burned off, damage has been remarkably small - a testament to the robustness of the design, manufacture and maintenance of modern transport.I wonder if Uncle Bernie has considered the interesting effects of racing F1 tubs in a thunderstorm?
Dikitriki
Flying Squad
Hi Jim
I also thought about my language and the 'mudiness' of your name
Thank you for your offer. Graham is hoping to get some at the kite show. If he can't then perhaps you can swing into action.
Yours
Richard
adrian
Flying Squad
Yes it is much "more of problem" with carbon fibre. Despite the carbon fibre being a good conductor it is embedded in a nice insulator, the resin. So the carbon fibre panels as a whole are poorer conductors, in the case of lightning strikes it can cause much more localised heating, which the resin doesn't like, the current would then try to find the path of least resistance, which in an aircraft wing may be the fuel tank, actuator cables etc.
The composite design often includes a metal gauze built in to provide a conductive path for the lightning strike. At work to test the lighning strike protection they have built a big metal rig to around the the aircraft and fire "lightning" at the wing
daifly
Western Thunderer
No argument with any of that but the original comment which provoked my reply was related to a F1 car which although having a carbon fibre body is surely insulated from the ground by four very substantial rubber tyres rather like a normal car. With the highest point standing about a metre above the ground it hardly presents an easy path of least resistance in comparison to the plethora of alternative paths around the racetrack.
Dog Star
Western Thunderer
I have been to the Kite do and found the relevant stall. No 1 metre lengths of 2mm dia. GRP rod.... so I have bought a number of 1.5 metre lengths of that material. I intend to cut the stuff into 0.5 metre lengths so a request for 2 metres will be posted as 4 of 0.5 metre pieces.
To those who requested some... please PM your postal address so I can take the packets to the local PO on Wednesday morning.
regards, Graham
To those who requested some... please PM your postal address so I can take the packets to the local PO on Wednesday morning.
regards, Graham
D
D7093
Guest
Don't know if this link is of help, I'm guessing its the same stuff. But if anybody needs some and didn't get any through Graham, Ebay have some.
It is for 5 metres, more than you'll probably ever need, but works out at £5.40 plus £3.50 postage and should be straightforward to purchase.
http://www.ebay.co.uk/itm/370308938...AX:IT&_trksid=p3984.m1438.l2649#ht_1453wt_698
You may have to join this link if broken.
Trevor.
It is for 5 metres, more than you'll probably ever need, but works out at £5.40 plus £3.50 postage and should be straightforward to purchase.
http://www.ebay.co.uk/itm/370308938...AX:IT&_trksid=p3984.m1438.l2649#ht_1453wt_698
You may have to join this link if broken.
Trevor.
Dog Star
Western Thunderer
Returning to the engineering aspects of these spilt axles - please can we have some details of the method of construction, including:-
* drill size (or sizes) for the bore through the axle;
* epoxy brand / specification;
* how to get the epoxy into the axle bore without clagging (a good Wessie term that) the internal screw thread;
* mandrel speed when turning the radial groove.
Cynric - what is the run-out of the axle end after the final manufacturing operation?
regards, Graham
* drill size (or sizes) for the bore through the axle;
* epoxy brand / specification;
* how to get the epoxy into the axle bore without clagging (a good Wessie term that) the internal screw thread;
* mandrel speed when turning the radial groove.
Cynric - what is the run-out of the axle end after the final manufacturing operation?
regards, Graham
Steph Dale
Western Thunderer
Graham,
It's all in the link posted I posted earlier...
But, for your quick reference:
* 2mm
* DevCon 2-ton
* Oil the screws then fit them to the axle whilst the glue cures. Remove screws, re-form thread with plug tap.
* Pass - Cynric, what did you find? Or; use a piercing saw on your workbench.
Run-out? Well if the GRP rod goes in as a running fit and the adhesive bonds around it properly then bu88er-all. I've got a test axle here with two of these sorts of break in it - even with a pair of Slater's 6'6" drivers there's nothing discernable.
Steph
28ten
Guv'nor
For the screws I just ran a plug tap through, i didn't bother with oiling the thread. The axles are held in a collet, the slides are locked, and straight in with a parting off tool, I couldn't tell you what speed, as I just go by the sound and feel. There is no run out, it is a very simple and quick operation with a lathe.
iploffy
OC Blue Brigade
daifly
Western Thunderer
For an example of Path of Least Resistance, take a look at
Watch it several times in full screen mode.
Watch closely at the tail of the plane for the lightning strike.
Then replay it and watch the front landing gear.
You’ll need to watch it a few times; it’s only about 11 seconds.
Three key things/areas to watch – first, watch the tail of the aircraft as the bolt hits the fin.
Then, look just to the left of the nose gear.
That brown square on the ground is a metal plate embedded in the concrete with a small manhole cover.
The strike exits onto the metal plate and sends the manhole cover flying through the air toward the tug on the far left.
Watch it several times in full screen mode.
Watch closely at the tail of the plane for the lightning strike.
Then replay it and watch the front landing gear.
You’ll need to watch it a few times; it’s only about 11 seconds.
Three key things/areas to watch – first, watch the tail of the aircraft as the bolt hits the fin.
Then, look just to the left of the nose gear.
That brown square on the ground is a metal plate embedded in the concrete with a small manhole cover.
The strike exits onto the metal plate and sends the manhole cover flying through the air toward the tug on the far left.