The Dauntless.

[785boats]

I've been building the kit of the Dumas Dauntless over the last month or so. Taken a break from building fast boats for a while & have gone back to my first love of scale boats.

I'm not sure if this forum is for full build threads or just photos of finished boats. So I thought I'd just post a few pics of the progress.
But if anyone has any specific questions I will gladly answer them.

She's a nice big boat at 49 and a half inches long.

What it should look like when it's finished.
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The basic frames & keel on the board.
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Adding the rear hull skins.
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The front hull planking being added.
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Adding the sides to the hull.
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[785boats]

More pics.

The planking to the sides at the front of the hull.
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The vertical planking at the bow completes the basic hull.
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The hull was then released from the building board, And the decks were added.
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Then it was on to assembling the cabins. The rear one first.
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The front one next.
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[785boats]

Then it was on to all the fiddly bits for a while. Carpentry in miniature.

I started with making the louvered vents.
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Here's most of the rub rails, vents, hatches, doors, architraves, the helm, rear steps, dinghy etc.
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After much filling & sanding, the hull was given a layer of 2oz glass cloth & epoxy resin, then some coats of primer & a soft grey finish coat on the bottom. Haven't painted the sides yet.
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The cabins were painted with white & the soft grey for the decks.
Today I have started adding the woodwork to the cabins. Fiddly, but satisfying work.
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Another view from the rear. Still a fair bit to add on yet.
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So that's the progress so far.

A happy & safe New Years celebration to all.

[jantagg]

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Here is the Dauntless that I built. It is a great boat and runs like the real thing.

[jevmax]

Tis a sight to behold underway!

[785boats]

Beautiful work man. It is a glorious looking boat.
What did you power yours with? Motors,ESC's, batteries etc.
I guess what I'm asking,does it need much power to get it up on the plane at a scale speed?

[Diegoboy]

She is looking great! How long did it take you from start to present?

[785boats]

Thanks mate.
About 6 or so weeks. But I have also built the hull & superstructure of the Dumas American Enterprise kit at the same time. Another 50" boat.
The thing is, I'm out of work at the moment so I get to spend a bit of time on it during the days. Not just in the evenings.

The American Enterprise.
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[785boats]

Here's a couple of pics from the last few days work.

The main cabin. Fitted the helm, hung the door, & laid the carpet.
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The rear cabin. Added the steps, hung the door, laid the carpet & installed some seats.
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Built & installed the mast. It's removable for storage & handling.
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Added the handrails , vents, running lights, horns etc.
That's when I noticed that I have installed the two hatches on the wrong sides. So I had to swap the vents over too. Stoopid me.
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An overall shot from the rear.
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The captains chair & some seats in the main cabin to tackle next. Need to find some pictures for that.

Do you guys know the philosophy on the venturi at the front of the boat? What it is supposed to do on the full size boat?
I don't like the look of it & am considering putting a capping strip on it.

[bogieboy]

very nice.....i just recently started a Dumas 19' chriscraft racing runabout myself...

https://forums.offshoreelectrics.com/showthread.php?60705-Christmas-came-early-CrisCraftmas-i-should-say

[785boats]

Sweet. I missed that thread.
I like the look of that boat. I'll keep an eye on your build.

[785boats]

I found a pic of part of the captains chair & made one up from a wire coat hanger, a bit of 1/16" ply for the base & some 1/4" balsa for the seats. 1/8" ply for the foot rests.

Chrome spray for the frame & some acrylic paint for the tan leather look on the seats.

The bits.
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All assembled and in position.
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A view through the front window.
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I just finished the bench seats for the main cockpit too, and added them in. Still have to make the padded cushions & seat backs yet.
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[Diegoboy]

Do you guys know the philosophy on the venturi at the front of the boat? What it is supposed to do on the full size boat?
I don't like the look of it & am considering putting a capping strip on it.

I found this post (http://experienceboat.blogspot.com/2015/02/design-621-commuter-yacht-dauntless.html?m=1), which gives a brief history, and also this video (https://youtu.be/1xibOL9FZPE) where the cameraman claims that space to be for seat and anchor storage.

[785boats]

Thanks for all that.
So sad to see a grand old boat in such a sad state. I think she's been completely broken up now.

One thing I did notice in the video, at 3:41, was that there are some louvered vents in the rear cockpit on the inside of the transom. Looks like I've got to make a couple more for that now.
They're not shown on the drawings that come with the kit. I'm on the hunt for some photos of that area now.

[Doug Smock]

Very nice work as usual!:thumbup1:

[785boats]

Thanks Doug.
It's good to get back to a bit of 'slow boat' building.

Here's a bit of work from yesterday.

Seat cushions for all three cockpits carved from balsa & painted to represent the tan leather. Just sitting loosely in place.
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Fitted to the main bridge area.
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The rear cockpit.
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The front cockpit.
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[bogieboy]

looking very nice!!!

[785boats]

Thankyou bogieboy.

Here's last nights effort.
I soldered up the frame for the canopy & covered it with some white linen.
I'm not sure about the rolled up sides. I don't know if the early version had them.
But later in its life there were some clear plastic sides that were rolled up when she was underway.

The frame.
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The cover.
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Another view.
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[785boats]

The two prop shafts that I had been waiting for arrived the other day, so now there was a good reason the get the drive lines & rudder setup done. Then I can finish painting the hull.

The stuffing tubes had to be cut down & the end bearing popped out of the off cut & pressed into the shortened tube. Nice little flanged ball bearings they are too.
For the skegs I used some shortened 4mm struts with an extra bush pressed in on the prop side for extra longevity. The skegs were just recessed through the hull with a support blocks epoxied each side of them inside the hull.

Motor mounts were made from some 3mm aluminium angle.

The motors are a couple of Turnigy G32 770kv outrunners. They've been in the spare parts box for about 6 years. They should work well on 4s driving the 45mm 3 blade scale props.

The visuals.



I used a long shaft to get the mounts bent to the correct angle & to mark the center of the motors.
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Before cutting the stuffing tubes down I used the full length with the shaft all the way back to the skeg to get the the mounts epoxied into the correct positions.
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The finished installation complete with epoxy putty to support the end of the stuffing tube.
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The basic rudder setup. Also shows the skegs & support blocks.
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The underside.
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[785boats]

Nearly finished now.

The hull sides & the deck are painted.
Made up some exhaust ports, the capstan winch, jack staff, & the davit for the tender, from bits & pieces of rod & tube etc..
Fitted everything in place, along with the anchor, and the chocks & cleats around the deck edges.
I've never liked the look of the exhausts on the original boat. They were too high up on the transom. So I've moved mine down to just above the waterline.
I think they look better.

Looks like I picked the wrong shade of blue. It should be darker
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Chocks, cleats, jack staff added to the deck, & the exhaust ports in the transom.
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The anchor & the capstan, chocks & cleats.
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The davit for the tender. Need to make up a pulley & add some rope yet.
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The maiden isn't far away now.

[jantagg]

On my boat I power with a single motor Turnigy T600 Outrunner for a 600 Heli (880kv), I bought from Hobby King. The ESC is a OSE 150amp.

[785boats]

That's interesting. Haven't seen a Dauntless with just a single motor.
What voltage do you use, & what size prop? I don't suppose you know the current draw by any chance do you?
I'm just trying to gauge what sort of power the hull needs to get up on the plane to a good scale speed.

[jantagg]

I'm using 2 2cell 5000mah lipo packs, in parallel That gives me plenty of run time.

[785boats]

Thanks for the info. But what size prop is she turning?

[785boats]

Just got back home from her sea trials.
Total success.
I initially ran it on 4s lipo but it was way too fast at full throttle. About fast scale cruising speed only took 1/5 of the throttle travel.
I ran the boat for about half an hour on 4s varying from full throttle to cruising to slow maneuvering, finishing with two laps at full throttle to get a gauge on the heat.
Both the motors & the ESC's were barely warm to the touch. No watercooling on anything, so I'm happy with that. Unfortunately the ameter I took to the lake wouldn't work, so no amp reading. I've got another one somewhere so I'll try that one tomorrow.
Both packs still had 68% & 64% capacity left in them.

So I changed down to 3s packs which is what is in the video.
Full throttle is still too fast but cruising speed is now about half throttle travel. Much more user friendly.
Still no temperature to speak of in the motors or ESC's.

Again, cruised around with slow speed & full speed for around half an hour
Packs were at 72% & 74% remaining.

The only disappointment is the whine of the motors. Never heard motors like that before. But I can live with it.

Here's a few pics from the lake, & a short video
The first little part is what I think is scale cruising speed, with a full throttle pass, out the back, at the end.

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https://www.youtube.com/watch?v=UZ8_JxG3xc8

[785boats]

Had another little test run today, but it was rained out before I could try any timing changes. I wanted to try and reduce the noise of those motors.

The current draw is as follows.
On 4s lipo (14.8v),at full throttle, each motor pulls 29 amps. But the boat is way too fast for scale.
On 3s lipo (11.1V), at full throttle, each motor pulls 21amps. Total power 466 watts.
Still a bit too fast but much more manageable with throttle control.
At a fast scale speed ( about 3/4 throttle)the motors pull 18A each. Total power 400 watts.
Pretty economical for a 50" boat, I reckon.

Cheers.

[bhorowitz]

That's a beauty.

[vvviivvv]

I’m also refitting my large scale twin and trying to figure if I should water cool it or not... it’s a rare Hull and I don’t want to drill it,

Seeing your run times and temps gives me hope... it’s a 1.3m twin I’ll run on 2x 1521 1y and 3s lipo (because I have lying around) esc will be swordfish 220

Had thought about running 10k mah / side for long run times, it’s twin jets with plastic 35mm impellers....


I had thought up a internal cooling system using a gas fuel tank and mhz pump but might not need...

[785boats]

That's a beauty.

Thankyou. Scale boats were my first passion before I was bitten by the FE bug.

[785boats]

I’m also refitting my large scale twin and trying to figure if I should water cool it or not... it’s a rare Hull and I don’t want to drill it,

Seeing your run times and temps gives me hope... it’s a 1.3m twin I’ll run on 2x 1521 1y and 3s lipo (because I have lying around) esc will be swordfish 220

Had thought about running 10k mah / side for long run times, it’s twin jets with plastic 35mm impellers....


I had thought up a internal cooling system using a gas fuel tank and mhz pump but might not need...

A 35mm pump at only 17000 revs won't pull a lot of amps. Not enough to trouble those motors & ESC's without cooling. Heaps of headroom there.
But as with most scale boats we don't run flat out all the time. so cruising speed will be an even lower amp draw.
Just do what I did & hook up an amp meter for some readings on the load.

What boat are you working on?

The American enterprise that I'm also building has 3 26mm jet pumps with 1350kv outrunners on them ESC's will be 120A car type with a fan on them. No water cooling needed in this boat either. It's also a 50" long boat.

The three pumps & motors.
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[vvviivvv]

That?s what I thought,

I did like the ?project? of internal cooling...

Boat in question is my Atlantic challenger... had it I?d say 15 years originally it was 700bb turbos 12v lead acid... then went brushless but blew the reduction belts so now direct drive as it?s impossibleto get replacement belts

Sorry for the high jack but here she is on the bedroom floor

[785boats]

Beautiful boat.
Direct drive is always better in my opinion.
That's some expensive motors & ESC's you are using. But Hey If they are just lying around they might as well be put to good use.

No Hijack involved here mate. It's all about sharing information & ideas.

Cheers.

[785boats]

A little developement on the Dauntless.
If you go back to post #25 on page 1 of this thread, you will hear the whining of the G32 outrunner motors in the video. I thought I would get used to it, but I couldn't. It bugged the hell out of me.
I ordered a couple of D3548 790kv motors from Banggood. Just to see if a different outrunner would create less noise. They are a bit smaller but have similar power & kv ratings.

https://www.banggood.com/Flash-Hobby-D3548-790KV-900KV-1100KV-3-5S-Brushless-Motor-For-RC-Airplane-p-1628283.html?rmmds=myorder&ID=47988&cur_warehouse=CN

Well, I'm glad to say that these motors are much quieter. Worth every penny.
Here's a test video shot today at the club. Just a faint little high pitch noise at about 1/4 throttle, but at higher speed they were nice and quiet.
Just thought I'd share.

https://www.youtube.com/watch?v=wy7pJyIJnmk