Scubapro D400/MK10 for Pony Bottle?

[Locus]

This doesn't make a lot of sense, but it won't hurt anything. To me the ideal pony reg set up would be a MK2 with an old metal case 109 2nd stage. MK2 because it's an unbalanced downstream piston that is dirt simple and almost incapable of not supplying air. There are no dynamic o-rings subject to HP air, which means a HP leak is almost unheard of, and coupled with an unbalanced 2nd stage, will give low-on-air divers some warning before the tank empties. I have read, (but not tested for obvious reasons) that the MK2 is more flood-tolerant than diaphragm or balanced piston 1st stages as well, and it makes sense given the design.

The 109 is perfect as a pony 2nd stage because it's extremely durable and can take a serious beating, has an adjustment knob which allows divers to really crank it down when not in use, preventing an inadvertent free flow. It's a very smooth breathing regulator as well, can go years between rebuilds, and service parts consist of 2 o-rings and a puck seat easily available for pennies.

But your MK10/D400 will be more than sufficient.

My cave set up consists of 2 MK10s, a D300 primary and a 109 alternate. I'm thinking of switching the MK10s out for MK15s, and may do that someday when I'm really bored, there's no decent sports on TV, and I'm trying to avoid doing something productive.

Thanks for the detailed reply. My logic was to take a page from Steve Lewis' book, that your pony reg should be the best reg you own, since it will be on standby for high-demand situations. Your choices seem very well thought out though. Would maintenance costs on a MK2/109 be lower than for a MK10/D400 for someone like me who doesn't do his own servicing? I also hadn't considered how much abuse a pony reg will likely take. Will my D400 get wrecked on a pony?

 

[redacted]

Thanks for the detailed reply. My logic was to take a page from Steve Lewis' book, that your pony reg should be the best reg you own, since it will be on standby for high-demand situations. Your choices seem very well thought out though. Would maintenance costs on a MK2/109 be lower than for a MK10/D400 for someone like me who doesn't do his own servicing? I also hadn't considered how much abuse a pony reg will likely take. Will my D400 get wrecked on a pony?

With Scubapro terminating support for D-series, it may be difficult to find shops that can/will service them.

 

[Locus]

With Scubapro terminating support for D-series, it may be difficult to find shops that can/will service them.

Presently I have a shop that can work on it. They've estimated ~CA$160 parts+labour to overhaul it (first stage and one second stage). Since I got it for nothing, this would be my sum investment in the reg (not including appropriate hoses, mini spg, etc) until I decide it needs service again. Is this more cost effective than purchasing another reg (eg MK2/109) that is already serviced? I can always switch later if I can no longer find a tech.

 

[redacted]

Presently I have a shop that can work on it. They've estimated ~CA$160 parts+labour to overhaul it (first stage and one second stage). Since I got it for nothing, this would be my sum investment in the reg (not including appropriate hoses, mini spg, etc) until I decide it needs service again. Is this more cost effective than purchasing another reg (eg MK2/109) that is already serviced? I can always switch later if I can no longer find a tech.

The point is, unless you go for DIY or find an "unauthorized" source of service, the life of your new regulator may be unnecessarily limited. $160 sounds a bit expensive but it may be the dollarettes thing.

 

[Locus]

The point is, unless you go for DIY or find an "unauthorized" source of service, the life of your new regulator may be unnecessarily limited. $160 sounds a bit expensive but it may be the dollarettes thing.

I live in Vancouver and costs are steep here, so I think it's a fairly typical charge for an unwarrantied reg service. My Mares regs have "parts for life" and they still cost me $130/year. Judging by the cost of the MK2/109 on ebay, if I can get a year or two out of the D400 before reservicing or switching to a more common reg, it should probably be worth it.

 

[halocline]

As you are finding out, the "free" parts for life programs are anything but free. I would suggest you get the MK10/D400 serviced once, then use it as your primary reg for 3-4 years or 100-150 dives at which point you could either sell it or get it serviced again. At least try it, you might really prefer it to the mares.

The idea that your emergency reg should be "the best" is silly. What you want in an emergency reg is reliability, not high performance. The high performance reg you want to take advantage of by using constantly. I certainly would not go out and buy a MK2 and 109 2nd stage unless you can: A) get them at a good price, and I'm afraid the word about the old SP metal case 2nds is getting around and pushing prices up, AND B) learn to service them yourself or find a kind soul to help you. Otherwise I'm sure your mares reg is more than up to the task of pony use.

For reference, I paid $84 for a MK10/D300 in great condition a few years back, and $100 for a bucket of five 2nd stages; three 109s, once of which looked like it was brand new, and two Air1s. So, $20 each ain't bad. It always shocks me that someone would have to spend $160 every year just to keep the o-rings and seats changed in these very simple and very inexpensive regulators.

 

[redacted]

I live in Vancouver and costs are steep here, so I think it's a fairly typical charge for an unwarrantied reg service. My Mares regs have "parts for life" and they still cost me $130/year. Judging by the cost of the MK2/109 on ebay, if I can get a year or two out of the D400 before reservicing or switching to a more common reg, it should probably be worth it.

I would be thinking in terms of 5 years or more. The mechanical spring is quite light so the seat may last quite a long time.

 

[Locus]

I would suggest you get the MK10/D400 serviced once, then use it as your primary reg for 3-4 years or 100-150 dives at which point you could either sell it or get it serviced again. At least try it, you might really prefer it to the mares.

Ok, I'll give it a try. Once it's serviced I'll use the SP 1st stage with the D400 for primary, mares carbon42 as backup, and my mares MR42 1st and proton ice 2nd on the pony. Anything amiss there?

 

[rhwestfall]

nah, forget all that, and just send it to me....

 

[Locus]

I'll get right on that....