'67 Blonde Miss Bardahl 1/10 Shovel

[BHChieftain]

Here's a 1/10 1967 Miss Bardahl shovelnose build.

Hull is a Karelson low profile, carbon fiber, built by Craig Bradshaw from West Coast Custom Boats. I asked Craig to paint her in the Blonde 1967 color scheme, and to install the hardware-- he did an awesome job. She is set up for RHT but can be setup to run LHT by moving the fin to the left side, changing the motor direction and changing props. Decals are on order.

Planning to run a proboat 1500KV motor with an X447, but will also try a proboat 1800kv motor with an x445. Not looking for a speed demon but would like to have it run stable in the mid 40's.

I hear these hulls are not really able to be waterproofed esp. if capsized, so I'm planning to build a waterproof radio/esc/servo box, still thinking about how to design that.

So on my todo list:
-Finish decals
-Build/paint the V12 motor model and driver
-Build rx/esc/servo waterproof box

Any tips on the best way to seal the motor bay?

Chief

[BHChieftain]

Given that these hulls are not designed to stay dry inside, what's the best way to minimize water intrusion? Are auto-bailers on this type of hull a good idea or am I just askin' for trouble with those (I heard they can flood the boat if something blocks them)?

Chief

[BHChieftain]

Decided to skip the bailers and just use some sponges. Planning to use a proboat 60A ESC which comes in a highly water resistant box already-- I'll add some additional liquid electrical tape to it. Will use a Traxxas waterproof RX box.

I lost my source for decals-- anybody have a lead on where I can get some cut?

Chief

[JimClark]

Contact Mike McNight at
http://www.thunderboatgraphics.com/

He has all the graphics you need for that boat

[BHChieftain]

Thanks for the lead,
Chief

[BHChieftain]

I'm looking for a semi-permanant sealing material to seal the prop strut from the inside of the hull-- I don't want a permanant material like epoxy as I want to be able to adjust the strut from time to time.

Silicon? Hot Glue? Silly Putty?

Chief

[westbeach]

Aquarium grade silicone might be the ticket you're looking for.

[lenny]

Hi,
Why are these hulls not designed to stay dry ?
What do you mean by that ?
Mine came with auto- bailers installed in it,
And I made a water proof seal with three thumb nuts for the hatch.

Thanks for any info.

Given that these hulls are not designed to stay dry inside, what's the best way to minimize water intrusion? Are auto-bailers on this type of hull a good idea or am I just askin' for trouble with those (I heard they can flood the boat if something blocks them)?

Chief

[BHChieftain]

Hi,
Why are these hulls not designed to stay dry ?
What do you mean by that ?
Mine came with auto- bailers installed in it,
And I made a water proof seal with three thumb nuts for the hatch.

Thanks for any info.

The open motor bay looks pretty tough to seal -- see pics. I'll try a sponge first as I don't want to drill more holes in the hull for auto bailers-- I can always install later.

Chief
PS I should be able to work on this boat in a few weeks-- got sidetracked prepping a OPC tunnel for a race...

[BHChieftain]

Not much progress, been working on my son's 29' P-spec OPC racing tunnel. Did receive the boatstand, painted to match. I'll add green highlighs to the stand later. Also received the '67 bardahl graphics but have not applied them yet.

Chief

[BHChieftain]

All hardware / watercooling installed.

Took her out for maiden voyage today, tried x447 and m445 prop. Like the x447 better. Motor getting really hot, although the ESC is cool-- I think I had some binding on the driveline-- when I pulled out the motor I noticed it was pulling down on the shaft drive and putting pressure on the bushing.

Here's a video on the 3rd run, with a nice blow over flip. Landed right side up. A few runs later it flipped upside down and flooded, but no damage. I'm still playing around on battery placement-- seems to do better with the lipos as far up in the nose as possible.

Need to finish decals, driver, and model motor.

http://www.youtube.com/watch?v=9qIYBhEYv0A

Chief

[monojeff]

I use silicone on my 1/10 strut and stuffing tube it works well.
What esc are u using and what do u have the timing set at?

[BHChieftain]

Hi,
60A proboat ESC. Timing is set to "low" (not many choices for that esc...). For lubricant I had just used a couple drops of light oil on the bushings. Which silicon do you use?

Also-- for your 1/10, do you place the batteries out towards the sponsons, or do you keep them close together midline? (mine are midline at the moment). Debating if I want faster roll response as the sponsons bounce or do I want to dampen that with weight out towards the edges.

Chief

[monojeff]

You are using a good esc and timing is set correctly so not sure why heat is an issue.
I can leave my hand on the can after runs without a problem of heat I am not sure what exactly temps are but I would say right between warm and hot is about right.

I use 100% silicone from home depot usually.
You can get the bathroom kind its a red and white tube and is smaller so can store it easily in tool box or whatever.

You do not want the sponsons to hop because that will caus handling issues.
I put the batteries on the sides of the boat some people put them on 1 side vs the other depending on what works best and which way your turning.

Also what rudder are you using as this can be a big factor in handling.

For lubricant I use a mixture of chainsaw bar oil and mystery oil then for my strut I use grim grease.

These boats you want to free up the sponsons so they are not running wet but not to much or they will flip so CG can be adjusted according to conditions.
On a good day I will have the CG further back if there isn't that much chop.
Take a look at this for some setup tips.
http://classicthunder.org/SetUp/10comandments.htm

That should help get you in the ball park and can adjust from there.

I run a air damn on mine now that I have it running well in the mid 40s if I don't it will certainly blow over.
Also when I tend to put the batteries to far forward it wants to dive sometimes when letting off the throttle on chop so something to keep an eye on.

The smoother the better with these scale boats dont want any hoping or bouncing.
Have fun nice looking boat I know Jim likes it......

[JimClark]

How's the shaft line up? To seal my strut I mixed some epoxy with some microbaloons to thicken it and load that into a suringe and force some into the gap and make sure I get a nice little bead of epoxy around the strut.

[BHChieftain]

You are using a good esc and timing is set correctly so not sure why heat is an issue.
I can leave my hand on the can after runs without a problem of heat I am not sure what exactly temps are but I would say right between warm and hot is about right.

I use 100% silicone from home depot usually.
You can get the bathroom kind its a red and white tube and is smaller so can store it easily in tool box or whatever.

You do not want the sponsons to hop because that will caus handling issues.
I put the batteries on the sides of the boat some people put them on 1 side vs the other depending on what works best and which way your turning.

Also what rudder are you using as this can be a big factor in handling.

For lubricant I use a mixture of chainsaw bar oil and mystery oil then for my strut I use grim grease.

These boats you want to free up the sponsons so they are not running wet but not to much or they will flip so CG can be adjusted according to conditions.
On a good day I will have the CG further back if there isn't that much chop.
Take a look at this for some setup tips.
http://classicthunder.org/SetUp/10comandments.htm

That should help get you in the ball park and can adjust from there.

I run a air damn on mine now that I have it running well in the mid 40s if I don't it will certainly blow over.
Also when I tend to put the batteries to far forward it wants to dive sometimes when letting off the throttle on chop so something to keep an eye on.

The smoother the better with these scale boats dont want any hoping or bouncing.
Have fun nice looking boat I know Jim likes it......

Hey, thanks a ton for the tips.


I might be a bit confused-- on the silicon-- are you talking about using silicon sealant, or using silicon as a lubricant for the shaft?

The driveline has bushings only, including the strut, so I was only using a drop of oil on each bushing to lube it. Not sure how greasing the shaft would help anything if the friction points are only on the bushings (not like a flex shaft).

I'm using this rudder:
http://www.offshoreelectrics.com/pro...d=ros-mini-rud
Seems kinda small but it is what the builder recommended. Let me know if there is a better option

I'll mess around with the lipo positions. My boat is set up for RHT (rudder is on the left hand side of the transom, and turn fin is on the right side). Do I want the weight biased to the inside sponson (in my case, the right side) or the outside sponson?

I was considering adding an air-dam as well. If you have any pics on how you installed yours that would be great.




Cheers,

Chief

[BHChieftain]

How's the shaft line up? To seal my strut I mixed some epoxy with some microbaloons to thicken it and load that into a suringe and force some into the gap and make sure I get a nice little bead of epoxy around the strut.

Shaft stuffing tube is straight-- I did notice the motor position on the mount was pulling the shaft down, causing friction on the first bushing away from the motor-- I'm thinking that was causing the motor heating. I'll double check my motor position on the next run.

Chief

[JimClark]

yup that can do it Also I don't like to use silicone as that can give you reap problems if you have to repaint. I know there is a product that is supposed to solve this problem but just don't like to use silicone

[BHChieftain]

For sealing the gap where the strut exits the hull, I ended up using shoe goo. I taped wax paper on the outside of the hull around the strut and filled the gap with shoe goo-- let it dry and removed the tape/wax paper. So far so good.


Oh, by the way, instead of sponges I took a chamois and rolled that up and stuck it at the back of the boat. Does a real nice job soaking up the water that comes in thru the motor bay.

Let me know the best way to lube the shaft/strut given the solid drive + brass bushings--- do I need anything aside from a drop of oil?

Chief

[JimClark]

I just use a teflon based grease I have had for years

[BHChieftain]

I've decided to ditch the brass bushings in the strut and try lead-teflon bushings.

I also found a source for S209 welding rods for replacement drive shafts, so if you need any lemme know... I just posted a thread in the swap shop.

Chief

[BHChieftain]

Shaft stuffing tube is straight-- I did notice the motor position on the mount was pulling the shaft down, causing friction on the first bushing away from the motor-- I'm thinking that was causing the motor heating. I'll double check my motor position on the next run.

Chief

Located the problem. The boat is a CF hull, and the bottom of the boat has a little up/down flex to it. This put pressure on the straight driveshaft against the bushings, and caused excessive friction, and resulting motor temp problems.

To fix it, I could have stiffened the bottom of the boat, but I really did not want to deal with that. Instead, I replaced the straight shaft with a flex drive-- since I build the boat to run RHT (with LHT prop), I had this option available.

The builder put in a large stuffing tube (which had brass bushings at either end to suspend the straight shaft), and I was able to slide in a 1/4" stuffing tube which was a perfect fit. I installed a .150 flexshaft w/ teflon tube, and used lead teflon bushings in the strut. Worked like a dream-- boat is vibration free. I did a test run this morning and it is running great.

The nice thing is I can always pull out the stuffing tube if I want to run it with the shaft per NAMBA 1/10 class regs.

Next stop-- finish decals, build model motor, driver, etc...

Chief

[BHChieftain]

Graphics added,

Chief

[BHChieftain]

Here she is running on an x447, pretty much dialed in



Chief

[BHChieftain]

I've been playing with the COG-- this boat likes the batteries way up front, in the middle of the boat (as opposed to out towards the sponsons), slightly offset to the side with the turn fin. Having the packs that far forward makes it kinda difficult to insert/remove. The hull is CF and is very light, so I plan to add some lead weight up in the nose so I can bring the lipos back just a tad. Once I figure out the optimal balance point I'll replace the velcro strips holding down the packs with CF lipo trays.

I'm also planning to add a stuffing tube support mount, and later, some CF rails to stiffen the bottom.

Chief

[monojeff]

Finally think I just found a good CG for my boat after 6 months of tinkering.
GPSd it at 46mph with a modified prop.
My previous best heat racing top speed was 39.
Amazing what prop mods will do to increase speed.
My boat is just under 6 pounds and I think it might have a little more in it if I were running a different motor.
At moment I am running sv27 motor and it's getting toasty at this speed.
Not sure I can push it much further. Maybe a little bit.

[JimClark]

You could make a plate to attach the batteries to and then slide them up in the nose and have the plate attach with velcro in an area where it is easy to get the plate removed

I've been playing with the COG-- this boat likes the batteries way up front, in the middle of the boat (as opposed to out towards the sponsons), slightly offset to the side with the turn fin. Having the packs that far forward makes it kinda difficult to insert/remove. The hull is CF and is very light, so I plan to add some lead weight up in the nose so I can bring the lipos back just a tad. Once I figure out the optimal balance point I'll replace the velcro strips holding down the packs with CF lipo trays.

I'm also planning to add a stuffing tube support mount, and later, some CF rails to stiffen the bottom.

Chief

[BHChieftain]

I added 6oz of lead in the nose, biased to the turn fin side (right side on my boat), and this allowed me to bring the packs back a bit, and still keep the COG right behind the turn fin. The extra weight plus the airdam now keeps the hull on the water-- prior to this the boat wanted to lift especially entering the turns and I had to back off a bit on the throttle-- I can now run full throttle with the boat stuck to the water. She is handling really nice now.

Chief

[monojeff]

Good to hear you got it running better.
What does the boat weight rtr?
Sounds like you have your CG close to what I have mine at.

I'd be interested to know your prop weight.

[BHChieftain]

Next time I get her set up to run I'll weight the boat, and also check the prop weight.
Chief