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View Full Version : A lot of money but for what benefit?



BTS
22-01-2013, 04:02 PM
ap classic rebreather derilin handset covers | eBay (http://www.ebay.co.uk/itm/ap-classic-rebreather-derilin-handset-covers-/160960914867?pt=UK_SportingGoods_Scuba_Snorkelling Equipment_SM&hash=item257a04a5b3)

At fifty quid for the pair I might had given them consideration but 240.... not a chance...

Not so long back on 'the other place what wont be named no more right' someone made the same thing in ali, posted and too the feedback that maybe the point was being missed, I am assuming this is MKII...

steve6690
22-01-2013, 05:13 PM
Really can't see what a delrin cover achieves. Looks nicer I suppose. Now if you could get a DSS-style rubber mount with bungees for the Vision handset I would be tempted.

BTS
22-01-2013, 05:17 PM
Really can't see what a delrin cover achieves. Looks nicer I suppose. Now if you could get a DSS-style rubber mount with bungees for the Vision handset I would be tempted.

I think it is supposed to ad support around the weak point where the cable and handset meet, this is the point at which the inner cases crack, maybe it makes them less prone to being trodden on too but... keep them clipped up so they don't get trodden on, free of charge, the inner cases cracking was more to do with the gland being overtightened in house at AP so I here than anything else and that seems to have been, in the main, rectified... and if a case did crack it is less than 240 for a new one. Nice idea, priced itself out of the market though...

steve6690
22-01-2013, 05:29 PM
I think it is supposed to ad support around the weak point where the cable and handset meet, this is the point at which the inner cases crack, maybe it makes them less prone to being trodden on too but... keep them clipped up so they don't get trodden on, free of charge, the inner cases cracking was more to do with the gland being overtightened in house at AP so I here than anything else and that seems to have been, in the main, rectified... and if a case did crack it is less than 240 for a new one. Nice idea, priced itself out of the market though...

I agree. I think for 240 I'd rather just remember to clip it up out of the way.

Graham Smith
22-01-2013, 05:40 PM
Made from "Derilin"...????

240 quid for something in a material that doesn't even exist???

G

Oh, He means "Delrin" Hope his machining is better than his spelling.... ;)

Craig107
22-01-2013, 05:41 PM
240 for a set of shark wackers..........Bargain.

bubbleless
22-01-2013, 06:43 PM
Ditch-able weight s just need some quick releases on them....

matt
27-01-2013, 06:04 PM
I think it is supposed to ad support around the weak point where the cable and handset meet, this is the point at which the inner cases crack,

Most common point of micro-crack is in the screws on the end cap. I've never seem them anywhere else.

240. 5% the cost of a new unit, that's where I'd be looking :-)

Matt.

BTS
27-01-2013, 06:17 PM
End cap? Where do you mean?

matt
27-01-2013, 06:45 PM
If you remove the faceplate and then push out the plastic case from the outer housing you'll see 10 or 12 small screws holding the end-cap on. IMHO these are the weak-point, but as you say, the neck is also vulnerable as the case is hard.

Matt.

BTS
27-01-2013, 08:04 PM
OK, I get you now.... but unless these were over tightened during assembly stress fractures wouldn't occur sometime down the line would they?

Tunicates
27-01-2013, 08:32 PM
Small hole in thin plastic = stress riser. As the plastic ages and dehydrates then it's more likely to get cracks around holes, increasingly so with a hole with a very small radius. It needn't be a case of overtightening....

matt
27-01-2013, 08:41 PM
OK, I get you now.... but unless these were over tightened during assembly stress fractures wouldn't occur sometime down the line would they?

So you would think. Take a look at yours and see if they appear to have hairline cracks right where the screws go in - AFAIK the case is a service item, so I'd always recommend frequent (18 months?) service to make sure this doesn't catch you by surprise. My best guess for how the cracks here develop is due to impact which is impossible to eradicate on boats etc.

Matt.

BTS
27-01-2013, 08:50 PM
So I guess a preventative measure that comes in a lot under 240 would be a blob of aquarium sealant on and around each screw head?

matt
27-01-2013, 09:03 PM
So I guess a preventative measure that comes in a lot under 240 would be a blob of aquarium sealant on and around each screw head?

I've heard of people doing that, yes. I had about 3 cracked handsets in 10 years, never missed a dive, but worth knowing the symptoms and catching it early. It's the Achilles' heel of the Classic.

Matt.

Tunicates
27-01-2013, 09:12 PM
You'd almost think it was worth making a rubber boot out of something. Rubber maybe.
Silicon rubber even.


https://www.youtube.com/watch?feature=fvwp&v=DFgcVI_eG6Q&NR=1

jamesp
28-01-2013, 06:37 AM
ap classic rebreather derilin handset covers | eBay (http://www.ebay.co.uk/itm/ap-classic-rebreather-derilin-handset-covers-/160960914867?pt=UK_SportingGoods_Scuba_Snorkelling Equipment_SM&hash=item257a04a5b3)

At fifty quid for the pair I might had given them consideration but 240.... not a chance...

Not so long back on 'the other place what wont be named no more right' someone made the same thing in ali, posted and too the feedback that maybe the point was being missed, I am assuming this is MKII...

Looks nicely made. I never have the spare time to bugger around making stuff like this, always tuck in the day job.

A pair of handsets is probably starting out with around 40 quids worth of Material, then you machine about 80% away.
Judging by the step over marks they are using about a 10mm cutter to take the inside out, so its not done in one pass to depth, its not covered in burnt in swarf, so its not made by Halcyon; but someone who knows a bit about what they are doing.
There are at least four operations in each pair, looks like it would have been done with fixture tooling for some of the ops rather than viced.
Probably about an hour and a half to two hours actual machining time in each handset and at least six hours to get to the first one. Plus fixture costs and tooling (10 carbide range from 12~30 dependant on length, a 16 diameter, which would do the periphary is closer 60. high rake HSS would be 40). The allen key is about 30p and the screws about 4~5p each.

If its coming out of a commercial enterprise, they are charging for the costs. Most of those will be running at ~30~ 45 per hour depending upon usual market sector.

They would probably cost the same in aluminium. I reckon you would need to make at least ten sets to be able to do anything with the price, at that point ali would be cheaper.

Problem with the public, they want it all for sod all, think plastic is "cheap (delrin is probably dearer than ali); but will pay over the odds for badly made scrap if its got the right name(like the Halcyon back up torches I saw a while back that had melted swarf welded into the surface, scrap in any self respecting machine shop. On the shelf at full price in the UK).

BTS
28-01-2013, 09:29 AM
Problem with the public, they want it all for sod all.

Maybe the problem isn't with the public but is with the product being over priced for the benifits it offers.

nickb
28-01-2013, 10:24 AM
Maybe the problem isn't with the public but is with the product being over priced for the benifits it offers.Didn't you used to say that about helium?

BTS
28-01-2013, 11:46 AM
Didn't you used to say that about helium?

Me? No...

nickb
28-01-2013, 12:11 PM
Me? No...Oh right.....


OC trimix was, to me, an extravagance, it was expensive both kit and gas wise and wasteful. And why would I bother with the time and expenseMust have been somebody else ;)

BTS
28-01-2013, 02:14 PM
OC trimix is an extravagance and wasteful, helium, if used in a rebreather doesn't need to be extravagant or wateful...

I stick by the above but it has no relevence to this thread....