Dumas 45" Scarab

[srislash]

Alright boys. It took some patience but I think I have a pretty good match on this thing. It needs clear yet.
I still have the cockpit and windshield to do but it’s close

[srislash]

It’s bigger than the 2028 I believe. I’ll go measure.
Yeah I have a scratch built jet boat here too that just needs the gear installed. Built it in 2008 as I recall?? Lol .
Never seen water!!

Wow, that's a blast from the past. And I thought I had projects sitting on the shelf ��. What size is the Proteus motor you've got in there?

[fweasel]

Wow, that's a blast from the past. And I thought I had projects sitting on the shelf 😂. What size is the Proteus motor you've got in there?

[srislash]

Well I have this one down to paint work on the lid. I got a UBEC wired in and wired up a Flier 300 for 12s operation. Stuffing tube in, servo and rod in.

2E8B55D8-B193-4239-AE26-76FC5E583E77.jpgECD6A67F-4E9F-44CE-8C7D-DC1D938BFE42.jpg

Foam in for locating batteries and Rx in. I’ll get a couple more pics. So now I’m waiting on a 1/4 flex and paint and good to go

Oh yeah, built a funky oil reservoir

[srislash]

Well this project made it back on the table. I had another boat started for the winter but my custom parts will be awhile I think.
Winter has also had different things in mind for my time, haha!
I changed my mind on the S bend in the flex and redrilled holes for the more standard straight shot. The motor is mounted! I also picked up a 5” extension rudder for this one and got it mounted. I’ll tidy the steering gear next and then setup batteries based on CG.

78FA8C5F-70CE-4C7F-87E3-3503B737E377.jpg

[rickwess]

It'll be how comfortable you are tightening the screws into the well nuts. The tighter, the less float you'll have.

[srislash]

That makes sense. We'll see how it all fits together. Those rails are about 1/4" thick so they should get a firm grasp.

[rickwess]

I've used well nuts in a non-RC application and the bolt tends to "float" a little. Looking at your pic, I can't see you being able to compress the well nut much either. I'm picturing how much a full size car engine moves under acceleration. This won't move even close to that, but this a big boat with a big motor so you have to expect some movement. Aside from having someone hold boat in place in the water while you hit the throttle, I don't know how you could even observe the movement.

The wear point will be where your flex exists the stuffing tube. Maybe assume some movement and think about how to deal with the wear area.

[srislash]

Are you concerned at all about the flex in the well nuts?

I thought that was a bonus. A little vibration damping. That is all there would be.
Do you think otherwise Rick? Have I misthought ?

[rickwess]

Are you concerned at all about the flex in the well nuts?

[srislash]

That being on hold it is time to move onto the rear of the boat. I dug around and found this old school(Hughey I believe) gear.



That is about where I am at with this one now. I am leaning toward making some kind of cover that looks like an outdrive leg or something just to clean it up back here.

[srislash]

So a little update here, this is the layout I am going with, motor up front laying flat, flex using 'S' bend, batteries on sides, and radio gear in the rear. I am really considering the 12s2p format though 10s may be better. At 630kv I think 12s is not unreasonable. but we'll see. I am just thinking this way because I may buy new batteries for this and the R-42, anyway enough thinking aloud.



So to mount this motor in here I am using 4mm 'well nuts' which I found on a motorcycle site. I located the holes through my empty mount then used a Uni bit and my NEW knuckle gun/drill. That is the 'well nut' on the right in first pic:





These little guys are a great option, but because the mount is 5" exactly and these 'rails' are 5" exactly, I will need to mill some bosses into the mount so it will slip down over the little(1/16") lip that holds these nuts from falling inside.
So out comes this little toy:



But I needed to order a special new piece for it, A milling table.

[fox88gt]

I did some rough mental math of the cost just before Christmas and had a shudder.

I have the same Scarab kit sitting in my basement, brand new, in the box. You're right about these big hulls sitting around for a while before getting built. I put together a bill of materials to build the boat brushless, and also gas as a cost comparison, and got major sticker shock both ways. I've paid less for actual cars before!

That being said, once I can get over the sticker shock, its gonna get built. No way would I sell it

[srislash]

You did get it to fit nicely. First thing that comes mind.... what are you going to do about painting it!?

The as-is windshield does look a bit large.

My airbrush guy said he would be up to the task. And... I am thinking of changing some of the area at the flat edge of the opening and behind windshield. Maybe some straight black or something. I am not a fan of that 'tiger stripe' look.

[flraptor07]

Wow Shawn, that cockpit and side pannels came out nice!! I'm sure you'll get the windshield figured out perfect!!