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        Discussion 1/8 scale U-95 Hydro.

#1 785boats Jul 12, 2012 06:21 AM

1/8 scale U-95 Hydro.
8 Attachment(s)
Our club has decided to add 1/8 scale hydros to the calendar next year, so a few of us are starting the builds now.
Back in the early 80's I scratch built a model of the U-95 running a marinised Profi .60 nitro engine. Nice stable boat. So I decided to do another one. Only this time I bought the framing kit from 'ML Boatworks', & the cowling from the 'R/C boat Company'.
The cowling arrived some time ago but the kit arrived Tuesday.
Well I couldn't help myself. I popped out the laser cut bits & started glueing. I've got to say right here that the accuracy of all the pieces is absolutely stunning.
Anyway , before I knew it I had the frame of a hull sitting on the bench.
Here's a couple of pics of the real one & a few of the basic build so far.
Just need to get some 1/4" stringers & she'll be ready for skins & foam.

#2 bill34207 Jul 12, 2012 07:51 AM

Allright Paul. Nice to see another build starting in here.
The framing looks good. Any ideas yet on what you will be powering it with?

I guess it's easier to keep the liquid in the cans for the weight when they are of the non alcohol content. :D

#3 scorpion1 Jul 12, 2012 08:16 AM

I guess I'll have to try my hand at a build kitone day.....................

Looks great...................How long is that hull going to be from tip of sponsons to rear' transom'?

I'd recommend a Neu 2230, Castle 2028 or Leopard 5698(in that order) to get that thing flying. If its real light(mine's 23lbs loaded) then the new Neu 1530 could work, or a 2215.

#4 bostong Jul 12, 2012 12:50 PM

Very nice Paul.

#5 785boats Jul 12, 2012 01:58 PM

Thanks guys.

I've become a fan of the TP Power motors lately. The ones I have run cool & strong. So I was thinking the TP Power 5692 6 pole. Either the 780kv or the 1100kv version, on 8s. Not sure yet. Bear in mind, we aren't allowd to run parallel packs & 2 x 4s packs are the most I can fit in the nose to keep the weight forward. So 8s is it.

Bill, I still managed to drink a few of the weights while I was building it.:D

Scorp. The hull length is 42"

This is actually the first 'Kit' Boat I've built. All my scale boats are scratch built. I must be getting lazy in my old age. But it was a dream to put together.

#6 bostong Jul 12, 2012 02:11 PM

Paul, those TP motors look pretty awesome

#7 785boats Jul 12, 2012 02:22 PM

They are a good motor . I run the 4082 2180kv motor in a mono & a Hydro on 4s .
can't fault them.

#8 bill34207 Jul 12, 2012 05:17 PM

For 8s I'd suggest going with the 1100kv version Paul. I'm running a Neu 1527/1.5y (850kv) in mine on 10s 1p and wishing it was faster. My Miller is a bit on the porky side though. I'm guessing around 20 lbs after adding lead to the nose to get it balanced.

#9 scorpion1 Jul 12, 2012 07:34 PM

Can you run more than 8s for less amp draw and longer runtime since you are limited to 1p???? On 10s you can get the lower kv motor. Why are you limited?

#10 785boats Jul 13, 2012 03:12 AM

Thanks Bill. I was leaning more towards the 1100KV . I do prefer slightly smaller faster reving props over larger props on slower reving motors, that can create all the torque problems.

It's just the AMPBA rules here in Australia. 1P only.
I don't need extra run time. We only need a mill lap, 5 race laps, & a slow down lap. All over in a couple of minutes.
But 2 x 4s packs is all I can comfortably fit in the nose . 5s packs would have to move back further & then so would the motor & ESC. The COG will end up being too far back I think.
Another factor is that I have a lot of 4s packs but no 5s & I don't really want to start laying out a lot of money for more batteries.
Of course all this may change as the build progresses. The class doesn't start until next year.
I am listening to all suggestions (& I do thank you guys for them) as I've not built an electric hydro this big before. It's all new to me.
I really would like to see how efficient that 6 pole TP Power motor is too.

#11 scorpion1 Jul 13, 2012 09:41 AM

OK, but you are going to need at LEAST a 240a speedy for that 1100kv motor on 8s to spin any decent sized prop.

#12 bill34207 Jul 13, 2012 10:50 AM


Originally Posted by scorpion1 (Post 22152684)
OK, but you are going to need at LEAST a 240a speedy for that 1100kv motor on 8s to spin any decent sized prop.

I was thinking maybe it would be a good candidate for one of the new "waterproof" 300's. My hydro tends to get wet on the inside regardless of how well it's taped up.

#13 785boats Jul 13, 2012 12:46 PM

I've got the Swordfish 240A. The 300A is a possibility.
I'm planing on running a nice flat sub hatch that's east to tape down, so there should be no water in the hull. Hopefully.

#14 785boats Jul 22, 2012 02:21 AM

6 Attachment(s)
Well, it was my youngest boys' 18th Birthday party last night. Made for a good chance to cloister myself away down in the workshop & do a bit of work on the hull.
The party went on until about 3.00 in the morning (poor neighbours) but I crashed about midnight. Didn't get much sleep though.
Finished off the stringers that I'd started earlier in the week & sanded it all to shape. Then I added the bottom skin of the main tub.There's a little drop down section in the middle at the front which is quite interesting. Maybe it was to help reduce the lift on the original. And so too the model I suppose.
Anyhow, I took a few snaps & here they are. I'm enjoying this build.

#15 bostong Jul 22, 2012 04:46 AM

Looking good mate, did they drink all your "weights", so you had to find alternatives when epoxy had to cure :D

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