Topic: To build a K Class submarine (Read 57107 times)

Bob K · « **Reply #125 on:** April 06, 2012, 12:40:05 pm »

Andy you are a Star !

I know there are times when you must think I seem to attract problems like a neodymium magnet.

OK. I have a 40Mhz Multiplex Micro-IPD Rx here, got it through Westbourne. My error in not checking dimensions first. Measures 55.3 x 30.3 x 16.2. Just tried it without the case, but it's still too tight even before heat-shrink. Good idea though.

For Reference the 8 channel Sombra Labs Rx is 37 x 20 x 12. I could maybe ‘squeeze’ in 50 x 26 x 12 max.
The Shulze Delta dimensions you quote would be too big, but the 5 channel would (37 x 21.5 x 9). Ideally, with 4 servos + gas ballast + snort I would have liked 6 channels minimum.

The Corona sounds interesting, especially as its synthesised (no Xtal), and 9 channel, plus connector pins are on the end like the Sombra. At 36.0 x 18.7 x 8.2 that would fit nicely. Thanks for the link !
I assume I could use that with either my WFLY Tx or my new Futaba F-14, both are 40 Mhz.

With David’s appreciated explanation of probable interference if using the WFLY Rx as it is in very close proximity to motors and ESC etc, might it be advisable to mount the Corona Rx well forward of the ESC instead to reduce possible interference? There is approx 85mm between the ESC and the gas switch on the next O-ringed bulkhead. Although I do love David’s new ultra-compact electrics layout.

merriman · « **Reply #126 on:** April 06, 2012, 03:06:26 pm »

Bob,

Sorry that the current installation geometry is giving you such a problem with receiver choice and placement. When I designed the system, I only had the Sombra receivers (the SL-6 and SL-8) in mind -- not bothering to think at all that Aroosh had not provided receivers compatible on the more common European bands. Damn!

Give the WFly receiver a shot, but my experience with those things has not been a happy one.

David

Subculture · « **Reply #127 on:** April 06, 2012, 03:11:01 pm »

I didn't know neodymium magnets attract problems, iron filings yes, problems no.

It should be no problem with either of those radios, although I can't say for definate with the WFLY radio, as I don't have one of those. I have used this receiver with my FC16 and my trusty old Fleet Omega 7 and it worked perfectly with both. So your good to go with the F14.

It's best practice to keep the receiver as far away from the ESC and motors as is physically possible- easier said than done in subs though, especially the small ones.

I would set things up as shown, then start tinkering if things aren't behaving well.

Bob K · « **Reply #128 on:** April 06, 2012, 04:59:56 pm »

Thank you both.

No complaints on buying the 40Mhz WFLY system, at only US$89 (£56), it was about the same price as a 2.4Ghz Planet T5 here. Just a pity about the Rx in this application, and that Sombra don't do a 40Mhz version.

I have ordered the Corona that Andy recommended, no point in taking addtional risks over a hap'th of tar, and will wire it up with lead lengths that can mount either in the standard position or flip over to mount close to the forward end of the compartment.

When (and I don't mean 'if') this all works nicely I am sure it will encourage others to go down the SD25 sub-driver route.

Bob K · « **Reply #129 on:** April 10, 2012, 09:16:45 am »

Could be a long delay. Last week I ordered a special LiPo battery and Corona receiver from HobbyKing in Hong Kong. A rapid series of confirming emails about payment received and items being packaged for dispatch. Today they send me a confirmation that the items have been dispatched, but . . .
"YOUR ORDER MAY TAKE UP TO 45 DAYS TO ARRIVE.". !!!!

Whilst I accept the possibility of being held for up to three weeks in Customs, like the US LiPo-Guard recently, I sincerely hope that six and a half weeks max delivery quoted is not typical. I was hoping for just another week to restart building.

Subculture · « **Reply #130 on:** April 10, 2012, 09:30:31 am »

I've ordered from them lots of time. Never had to wait more than fortnight for the goods to show at this end provided the items were in stock when you ordered them. The fact that they've said your order is dispatched is a good sign.

Bob K · « **Reply #131 on:** April 10, 2012, 09:49:32 am »

Fingers crossed Andy

This is in R&D, but I'm keen to get going.

Bob K · « **Reply #132 on:** April 26, 2012, 07:55:09 pm »

Some progress on this long build saga !

On 10 April I ordered a Corona RP8D1 receiver plus a Turnigy 4000 mAh Lipo battery from Hobbyking in Hong Kong, only to be emailed on dispatch to allow 45 days for delivery. Well, they finally arrived, with a time span more indicative of ocean freight.

Good news is that the Corona Receiver just fits into the very tight space between the servos, motors and ESC. This will be my fifth receiver bought for this build, and the final option remaining to get an Rx that would meet the high spec and noise resistance required. Previous purchases have been the original WFLY, two Robbe/Futaba’s, and a Multiplex Micro-IPD.

The battery is proving to be more challenging. The Turnigy ordered, based on dimensions quoted online, turned out to be too tight a fit for the sub-driver tube. I had allowed for my estimate of the slight corner radius based on other batteries I have, but it came almost square cornered. This LiPo now joins the one I bought from Westbourne that appeared to match the US spec but was far too large. My ‘spares’ shelf is growing. Turnigy single-in-line LiPo’s tend to be too long unless reducing to very small mAh.

Today a club member recommended the Component Shop, saying how good their customer service was when asking unusual questions. Their advice was spot on. A five minute call describing the spec I was seeking, and that it had to fit inside a 60 mm ID tube in a space 130 mm long. He even measured the diagonal for me. I now have a 2800 mAh S1 25C that will fit the space ordered due to arrive within 48 hours.

Best part was they even asked what type of connector I wanted, and it is coming fitted with that.

Bob K · « **Reply #133 on:** April 26, 2012, 08:39:08 pm »

Silly Question?

Going "LiPo" still causes me concerns, especialy for underwater use. Looking online I can get standard 9.6V NiMh packs of almost identical mAh capacity that are almost identical in size to this 11.1V Lipo. In this case why use a LiPo at all? An NiMh can be charged in situ, operated with a magnetic switch obviating lake-side dismantling, and is unlikely to catch fire if it gets wet or upset.

I have a 2800 mAh NiMh running twin motors in my destroyer that happily sails for hours on a charge

Subculture · « **Reply #134 on:** April 26, 2012, 09:11:28 pm »

Sorry to hear the battery was too big. Always worthwhile making a simple cardboard template of the pack and double checking to see it will fit in easily.

Lipo offers greater energy density than NimH, and can generally deliver a lot more current. Also, although the packs may be similar in size, I would expect the NiMH pack to weight a lot more, so this could upset the balance of your boat- note I said could, not will.

Bob K · « **Reply #135 on:** April 26, 2012, 09:36:37 pm »

Thanks Andy. It was my estimate on the corner radii added to the H x W x D dimensions given, I knew it would be a close. Sadly too close to fit. Pity, it is a nice 4,000 mAh pack.

If you recommend I stick with the LiPo then I will do that. I am not sure what the design weight should be, but at least with a slightly smaller pack I can add ballast if necessary. This is all R&D after all. Hopefully starting assembly and wiring very soon, with pictures or course.

salmon · « **Reply #136 on:** April 26, 2012, 11:41:58 pm »

Quote from: Subculture on April 05, 2012, 11:55:34 am

http://hobbyking.com/hobbyking/store/__11612__Turnigy_4000mAh_3S_20C_Lipo_pack_Perfect_for_QRF400_.html

Thanks for the tip on this.......I would love this in my Gato! I will file this for future use (after my current LiPo die off).
Cheers,
Tom

Subculture · « **Reply #137 on:** April 27, 2012, 10:26:27 am »

Unfortunately a bit too chubby for the 2.5" subdriver.

salmon · « **Reply #138 on:** April 27, 2012, 06:46:55 pm »

Oh, I was just looking at the depth (length). Guess I should have looked at all the dimensions! Thanks for the heads up!

Bob K · « **Reply #139 on:** April 28, 2012, 11:15:40 am »

Highly impressed with www.component-shop.co.uk. New LiPo ordered late Thursday. Arrived this morning.
Fits inside the 60 mm ID tube nicely.

Question: I assume the 4 pin Lipo socket on the battery (R/Bu/Y/Bk) is used purely for monitoring whilst charging ?

Subculture · « **Reply #140 on:** April 28, 2012, 11:34:25 am »

It's actually used for the charging. Each cell is charged individually. On some chargers you connect both the balance connector and the main battery connector.

Bob K · « **Reply #141 on:** April 28, 2012, 11:40:39 am »

Thank you for that info. This is all new technology to me

K9 now on the stocks

mountfleet · « **Reply #142 on:** May 20, 2013, 10:25:23 pm »

Hi Bob k,
The K class that was videoed at Barrow is mine, she is K22, is 7ft long with a co2 ballast system.
I am going to be at the Norwich dive on the sunday if you can make it.
I'll sort some pictures out soon.
Adam

Bob K · « **Reply #143 on:** May 20, 2013, 10:59:56 pm »

Hi Adam. I remember that video. Very impressive. I must re-find the dates and info for this years Norwich event.

My own K9 has been on hold for a while, looking for an alternative battery type to Lipo that will still run it and fit in the limited space. In the mean time I have built a WW1 destroyer and a semi-submersible torpedo ram.

Davy1 · « **Reply #144 on:** May 27, 2013, 08:32:07 am »

Hi Adam,

Looking forward to seeing you and your sub again (I took the video at Barrow) - very impressive sub. I seem to remember you carrying it under you arm !

I will be at Norwich both days with the R Class.

See you,

David

UnbuiltEClass · « **Reply #145 on:** September 23, 2014, 10:07:00 pm »

Hi,

Great build, anything First World War is always nice to see.
There are some photos of onboard a K Class on the Imperial War Museum web site. You can grab or download the images. They've added a lot of First World War and Interwar photos recently, worth a look.

http://www.iwm.org.uk/collections/item/object/205318769

raflaunches · « **Reply #146 on:** September 23, 2014, 10:35:07 pm »

Wow, thanks for sharing with us, and welcome to the Mayhem.

With pictures like that I think me and Bob might complete our models!

Bob K · « **Reply #147 on:** September 24, 2014, 09:02:41 am »

That is a really useful photo. Thank you for posting it. Also, welcome aboard

I remain in an intermediate stage on such vessels, having recently achieved submergence (on a semi-submersible), but need to resolve the de-submergence aspects before intentionally heading out into the Gairloch.

TailUK · « **Reply #148 on:** September 24, 2014, 09:48:02 am »

Quote from: UnbuiltEClass on September 23, 2014, 10:07:00 pm

Hi,

Great build, anything First World War is always nice to see.
There are some photos of onboard a K Class on the Imperial War Museum web site. You can grab or download the images. They've added a lot of First World War and Interwar photos recently, worth a look.

http://www.iwm.org.uk/collections/item/object/205318769

Anyone any ideas about the object sticking up between the 2 raised hatches. I might be crazy but it looks like a depth charge thrower. Then again if they're daft enough to build a steam powered submarine they're daft enough for anything.

Bob K · « **Reply #149 on:** September 24, 2014, 10:11:16 am »

That is indeed a depth charge thrower. I think this photo of it is from the Submarine Museum.

They were also crazy enough to mount a 12 inch gun on one, and convert another to a seaplane carrier.

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Author Topic: To build a K Class submarine (Read 57107 times)