Old member....new build....scale build...

[ScarabChris]

Lightning fast shipping from OSE. I ordered the motor mounts and other parts on Friday and the USPS delivered on Sunday...hell Monday would have been fast.

Modified two mounts to make one dual mount for 5" rails. This is going to work so much better. So easy to pull the motors if needed.

[ScarabChris]

Some updates. Motor mounts in...came out nice.

[ScarabChris]

Graupner outdrives filled with real marine gear lube. Took the lower units off and filled them from the top. Then topped off the drives from the top fill.The oil lever is only filled to cover half the upper horizontal shaft leaving room pressure increases.

[Beaux]

Cool, that motor mount came out good. I like those quick change mounts.

[ScarabChris]

Float test.....CG looks good but I can play with it with moving the main battery. I have the LiPo, ESC's, servo, RX battery and battery tray just placed in to see how she floats. No leaks and floats nice. If it performs half as good as it looks I'll be happy.

[srislash]

Looks great Chris, nice job on the mounts.

[ScarabChris]

Hanging out in the shop last night, enjoying a few cold beers and did some work.

Steering servo mounted....I know it's a little tilted and it's driving me crazy. The beers had nothing to do with it, it's from leaning in the hull with my head upside down. LOL. I may remount it straight..
Got a little creative with the water cooling. Used some aluminum tubing to make it a little cleaner looking. The outer scale exhaust pipes will be for the ESC's. I want everything coming out those 4 pipes. I run in salt water mostly and flushing with fresh water is easier this way. I have a rig with 4 hoses that slip over those transom pipes and back flushes with the fresh water hose on the dock. Fresh water pushed in the transom and out the bottom.

[fweasel]

what did you use to seal the aluminum pipe against the cooling can elbows? The setup looks great.

[ScarabChris]

what did you use to seal the aluminum pipe against the cooling can elbows? The setup looks great.

It's a really tight fit. Had to ream out the tubing a little and grind down the barb on the nipple just to get the tubing on there. Once I could muscle it on and off I used a little 5 minute epoxy to secure it. Also epoxied the tube to the mount right where the screw holds the mount in to give it a little extra holding power.

And I'm always 2nd guessing myself. On the port side motor I should have plugged the lower inlet on the water jacket and relocated it to the inside so it looks uniform with the other motor. Both water intake tubes between the motors.

[ScarabChris]

It's ready for a test run. I got it powered up at about 11pm last night and out it in the pool just to check it out. Pool not big enough....LOL.

Still have to mount the RX and route wiring, also waiting on an "InvisiSwitch" to arrive to finish the wiring. But it's ready for an actual test run. I'll toss it in the canal behind my house today.

[ScarabChris]

Making some progress. I did a few test runs and this boat is WAY faster than I ever expected. Like crazy fast considering it has geared outdrives.

I was only able to see this speed for a few seconds because on the first run I blew the gears in one of the drives. The gear mesh has to be absolutely 100% perfect for them to hold up. But I think I got them just right.
Then the 2nd run I lost an ESC, my water cooling mod leaked and filled one ESC with saltwater and that was the end of that. Smoke and came in one one motor. Lucky I had 4 of these SeaKing 180's. Three of the 4 were good so I made the repairs and now I have two working ESC's. If I blow another I'm going to bite the bullet and buy another Hydra 240 and use those (I have one already new in the box)

The gears....I found some gears on ebay, they need some slight modification to work but they work and are cheap enough. But the way this thing screams I can see gear replacements being a regular thing. I will likely look for some better quality scale drives in the future. The Arrow Shark drives are way to big and the TFL drives are to small but I think MHZ has a drive that is similar in size to these Graupner 820's. If only I could find some stainless steel gears for these drives.

I'll get some video on the next test run. After I get it dialed in I'm going to break it down and sand and smooth out and put a new coat of paint inside and I have MonoJeff working on a wrap for the outside.

[srislash]

What do the gears look like? If you hunt around you may find some hardened ones. I found all kinds when looking for my ERevo

[ScarabChris]

What do the gears look like? If you hunt around you may find some hardened ones. I found all kinds when looking for my ERevo

Pretty standard 90 degree miter gears. You can see a picture of the gears on post #2 in this thread.

[srislash]

So those are brass with a 5mm shaft? I was thinking of hardening those but if brass perhaps not.
I know how it goes with that kind of replacement/maintenance and it is a PITA. Best to avoid it for sure.

[ScarabChris]

Yup brass and pretty sure it's a 5mm shaft.

I found these on ebay, just need the shaft hole bored out a little and grind the overall diameter of the gear points down a little. They will work, I have 8 of them and haven't needed to use them yet but I will soon. LOL.

https://www.ebay.com/itm/BOSTON-GEAR...53.m2749.l2649

[srislash]

Just a thought but may be worth an email: http://www.rushgears.com/services/replacement-parts
Or:
https://us.misumi-ec.com/vona2/mech/...iAAEgJQS_D_BwE

[ScarabChris]

Ok so I got the mesh on the gears just right....runs awesome. But I can tell by the wear the gears will not last. So I was able to obtain these AMPS drives from a member here. Pretty much brand new never mounted. These are like a time capsule from the 1980's, like brand new and I can tell these things are beefy yet lighter than the Graupner drives. Amazingly these drives have nearly identical dimensions to the Graupner drives with regard to size, distance between input shaft and prop shaft, prop shaft size, etc so I souldn't have to do much work to get them on. I'm going to work the skegs to get rid of that hideous long rectangle look and make them look more like a Merc drive. Stay tuned.....

[srislash]

Nice score

[ScarabChris]

Did some work over the Thanksgiving holiday. We actually took the RV camping and I set up shop at the campground. Nice stuff.....cooler weather, cold beer and tinkering with RC boats.

I threw in the picture of the bacon on the hot plate just because....LOL

[ScarabChris]

The one big thing that had to be done was making stand offs for the mounting bracket. The bracket is at an angle which would put the input shaft pointing down in the hull. So I mixed up some casting resin and colored it with black die. Once cured I shaped and sanded it. Came out great. Once painted they look like one piece.

[ScarabChris]

Reshaped lower units and skegs and brackets mounted...

[ScarabChris]

Drives on, waiting on some prop adapters and prop retainers and some other stuff from OSC to do the steering. Have to remount the motors too.

[ScarabChris]

Steering. Tried to replicate what the real deal looks like. I'll add some detail to the point where they go into the transom. These are flex cable prop shafts, I drilled and tapped the spring loaded ball rod ends from 440 to the size of the prop shaft. There will be a standard servo on each side of the boat (push/pull). The drives turn really smooth and there is the flexibility for adjusting the trim on the drives which I will likely do with the 3rd channel, trim on the fly.

[Beaux]

Lotsa work looks great.

[785boats]

Some nice engineering going into this build. Love it.

[ScarabChris]

Thanks!!

It's coming along. I had it pretty much wrapped up with the Graupner drives, the boat ran sweet with them. But the gears just will not last. When I came across these AMPS drives I had to do it. They are built to take the power and RPM of big nitro and gas weed wacker engines so they should hold up much better. And while the overall dimensions of the AMPS drives are nearly identical to the Graupner drives, I really did have to do the entire build again. The only thing I didn't have to alter was the ESC and battery mount.

I'm at a stand still right now, waiting on some parts. I should have it in the water by Sunday for some testing.

[ScarabChris]

Ugggggggg!

God I really HATE the USPS. I placed an order with OSE for some parts to wrap this up last Saturday (9/25) and paid for the fastest shipping hoping to have the parts by Wednesday or Thursday. OSE shipped on Monday the 27th as I expected they would. For some reason the USPS just doesn't want me to have these parts. All week it said Friday (12/1) delivery and I still do not have the parts. Last time I ordered from OSE with the expedited shipping I had the package in 48 hours...no joke.

Now the USPS tracking is stuck with this message...."The item is currently in transit to the destination as of December 1, 2017 at 9:10 am"....In my experience with the USPS that's code for "We have no clue where your package is and we have no clue when you will get it and we really don't give a crap"

Uggggggg...OK rant over. Carry on.....

[fweasel]

That sucks. Only consolation is that during the holiday rush, USPS still delivers on Saturday and Sunday, so maybe it will still make the weekend.

[jaike5]

great build, love the bacon!
Cheers, Jay.

[Peter A]

I ordered Monday as well. It was sent and has taken 5 days to get to NY. It still has to come all the way to NZ. It is usually faster but it is the silly season and carriers are swamped with packages. I just am hoping it gets here within the next two weeks before I go away on holiday. BTW, I like your build.... and bacon!