Go Back  RCU Forums > RC Boats > Speed - Electric
Reload this Page >

Blast from the past..Dumas Miller American convert to brushless

Speed - Electric For all your electric boating needs.

Blast from the past..Dumas Miller American convert to brushless

Reply

Old 07-02-2019, 08:20 AM
  #1  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Blast from the past..Dumas Miller American convert to brushless

Well hello there! after a long hiatus from all things RC, I now have the time/life to get back into it.
What I am looking for is any info or guidance to convert my Dumas Miller American 1/8 scale to lipo/brushless.
I started the build during a family issue as a distraction, and was going with a CMB greenhead .87 nitro, but now am re-thinking it.
I would be happy and grateful for any input given. Just looking in the past 2 days, I see the word "Leopard" for the motor, (1100 to 1200 watts? needed for this hull/weight), and a big ESC.

Again, any guidance would be of great help. I am in the final stages of detailing the hull getting ready for seal/paint,n and that's when I got the notion to go brushless.

THX

c

Last edited by flycaster2; 07-02-2019 at 08:23 AM.
flycaster2 is offline  
Reply With Quote
Old 07-05-2019, 07:14 AM
  #2  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,742
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Got any pictures of where you're at in the build? You may need to take the bottom off the boat to do the conversion you're looking at.
As for your original plan on using a CMB .67 green head, the boat was never designed for that much power and might cause issues when running. That said, it is very doable to get the boat running with that CMB but, as with all projects, there is a learning curve as well as a lots of testing

Last edited by Hydro Junkie; 07-05-2019 at 08:02 AM.
Hydro Junkie is offline  
Reply With Quote
Old 07-08-2019, 05:53 AM
  #3  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Good Morning Hydro,

Thanks for the response. And I will toss a few images here in the next couple of days. I knew the Dumas boats tend to be "heavy", (I did the sport AVL and a Miller back in the late 80s/early 90';s) so that's why I went with the green head. I did re-enforce the motor bay (side and bottom), the sponson rears, and the transom/bottom plate, just for "stress loading". I have no issues if I have to open the belly to re-do the driveline.
But with the "environmental/"social" aspects" of nitro, I was thinking I would get less grief from onlookers etc., etc., etc...
But I still love the smell of nitro/alcohol/castor as it burns...

Give a day or two and I will have some images up for your perusal....

THX!

Last edited by flycaster2; 07-08-2019 at 07:25 AM.
flycaster2 is offline  
Reply With Quote
Old 08-06-2019, 04:51 AM
  #4  
Bill Diedrich
 
Bill Diedrich's Avatar
 
Join Date: Jul 2006
Location: Ventress, LA
Posts: 1,383
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I am in the planning stage of build my Dumas Atlas Van Lines and doing it as a FE on 6 or 8 cells and looking
at using the Leopard 4092 at either 1390kv on 6 cells or the 4092 1050kv on 8 cells which would get me close
to the 30,000 rpm mark this boat will need to run and perform at. However I will be doing quite a bit of lightening
up of the formers and building side pockets for the batteries. This boat isn't going to be built for completion but
just for running on my local lake and the reason for electric is the noise factor of glow engines and also the headaches
associated with glow engines, tuning, pipe lengths and going lean and blowing the plug and possibly the motor. I
too love the smell of glow fuel but keep that for my model aircraft, boats are all electric. Going electric is definitely
a learning curve and expensive to start out with but once you have your charging equipment and get past the
initial cost of the motor, batteries and ESC, it is a no brainer as far as the boat ever quitting out on the pond or
lake and having to paddle out to retrieve it. Just remember though that the electric scale hydro is going to be quite
a bit heavier than the same as a glow engine boat, but once it is balanced (approx. 1/3rd of length back from the
forward tip of the sponson), the CG will never shift. Good luck with the conversion and keep us informed as to your
progress. When you have decided what you want to install as far as electric power give the guys at OSE a call and
they can guide you towards the best set up for your boat as far as motor, ECS and battery selection.
https://www.offshoreelectrics.com/index.php
Bill Diedrich is offline  
Reply With Quote
Old 08-06-2019, 12:47 PM
  #5  
Got RPM
 
Got RPM's Avatar
 
Join Date: Nov 2006
Location: AZ
Posts: 744
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Cool

You are not making the best power choices here @Bill D, this is a heavy boat with a rather obsolete bottom design. The Dumas AVL will not perform well on 6S, amp draw will be too high; use 8S. Install a 100 mm long motor with a Kv of ~850, more Kv will just eat amps. TP motors are more expensive but much better than Leopards and are available in the correct 100 mm size for this boat - 92 mm is really too short. An ESC with a minimum 150 amp capacity will work well. An x457 prop will give decent performance as long as the overall setup is good.

This is essentially the NAMBA 1/8 scale race setup, which is well-proven and relatively mild yet gives wonderful, realistic performance. If you’ve ever seen them run you will know what I mean. When you need more speed, change the prop.


.
Got RPM is offline  
Reply With Quote
Old 08-06-2019, 02:07 PM
  #6  
Bill Diedrich
 
Bill Diedrich's Avatar
 
Join Date: Jul 2006
Location: Ventress, LA
Posts: 1,383
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Do you have a link to the 100 mm long motor, as I couldn't even find it on the TP Power web site.
Bill Diedrich is offline  
Reply With Quote
Old 08-06-2019, 03:35 PM
  #7  
Got RPM
 
Got RPM's Avatar
 
Join Date: Nov 2006
Location: AZ
Posts: 744
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

TP will build you one, the 5Y is the closest. http://www.tppowerusa.com/motors/bui...series/tp-4070

Another perhaps better option is the HET 700-98-840, these are good quality motors too.
High-End Technology RC, HET-RC

I have run both brands in hard racing, never a problem.
Got RPM is offline  
Reply With Quote
Old 08-06-2019, 05:49 PM
  #8  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,742
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Here are the motors listed in the R/C Unlimited rulebook:
i. NEU 1527 1.5Y 850KV
ii. HET Typhoon 700-98 840KV
iii. Turnigy SK3-3994 850KV
iv. TP 4040 10Y 830KV

As far as ESCs and batter packs:
Electronic Speed Controls (ESC)
a. Any ESC may be used as long as it is rated to a minimum 130 Amps and rated to handle a
minimum of 8s battery configuration.
b. Anti-spark resistors are advised on all speed controllers.
Batteries
a. A maximum capacity of 8S Lithium Polymer (LiPo) batteries are approved. The maximum total
mAH capacity of the battery pack(s) will not exceed 6000 mAH. Only LiPo batteries with a cell
rating of 4.20 or less volts per cell are approved.
b. LiHV batteries with per cell capacities to 4.35 volts or higher are not approved.
c. Manufacturer’s minimum discharge of 30C constant shall be allowed.

These are what are allowed in R/C Unlimiteds. Throw in a hard or flex shaft with a 57mm prop and you're good to go
Hydro Junkie is offline  
Reply With Quote
Old 08-07-2019, 04:29 AM
  #9  
Bill Diedrich
 
Bill Diedrich's Avatar
 
Join Date: Jul 2006
Location: Ventress, LA
Posts: 1,383
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

This boat isn't being built for competition it just to have fun on the river with,
I live 1/2 block from a piece of property on the river that I keep up for a friend
that lives in Florida and it has a pier that I fish from and run one of my other
electric boats from. Have no plans on ever selling the boat so the motor selection
to either NAMBA or IMPBA rules isn't necessary, all I want is to run this boat
and have a little fun with it.
Bill Diedrich is offline  
Reply With Quote
Old 08-07-2019, 08:17 AM
  #10  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

This is what I am looking for, a few different ideas on which to start my research and such.
And I know I do owe Hydro and you guys some images of my 95% completed Miller American. Been busy at work, and even tho every day I see the boat on my bench, I just have to make the time to image outdoors.

But, I really think lipo is the ticket these days....Stay tuned folks, images soon..
flycaster2 is offline  
Reply With Quote
Old 08-07-2019, 03:39 PM
  #11  
Got RPM
 
Got RPM's Avatar
 
Join Date: Nov 2006
Location: AZ
Posts: 744
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Cool

....Have no plans on ever selling the boat so the motor selection to either NAMBA or IMPBA rules isn't necessary, all I want is to run this boat and have a little fun with it.
That is why we recommended the NAMBA setups, they are not normal full-blown race setups, but have limited power to be fun to drive and perform like the real thing. They are well-proven reliable setups, not what joe blow who has never run a big hydro thinks will work. Set it up however you want, but too little power means poor performance - and perhaps it won’t even plane off.


.
Got RPM is offline  
Reply With Quote
Old 08-07-2019, 07:35 PM
  #12  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,742
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Bill Diedrich View Post
This boat isn't being built for competition it just to have fun on the river with,
I live 1/2 block from a piece of property on the river that I keep up for a friend
that lives in Florida and it has a pier that I fish from and run one of my other
electric boats from. Have no plans on ever selling the boat so the motor selection
to either NAMBA or IMPBA rules isn't necessary, all I want is to run this boat
and have a little fun with it.
I posted what the guys racing use in their boats for a reason. IT WORKS!!!!!
That said, you're dealing with a heavier boat than the guys race with. To get it to run, be it in competition or just to fun run, will require more power than the dedicated racing boats will to obtain similar speeds. Equal power will give you a boat that will run but won't have the top end the dedicated race boats do. If you want to try to use lighter stuff, feel free. If that lighter stuff fails due to overloading, what can I say, that's the breaks of R/C boating
Hydro Junkie is offline  
Reply With Quote
Old 08-08-2019, 03:37 AM
  #13  
Bill Diedrich
 
Bill Diedrich's Avatar
 
Join Date: Jul 2006
Location: Ventress, LA
Posts: 1,383
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Hydro Junkie View Post
I posted what the guys racing use in their boats for a reason. IT WORKS!!!!!
That said, you're dealing with a heavier boat than the guys race with. To get it to run, be it in competition or just to fun run, will require more power than the dedicated racing boats will to obtain similar speeds. Equal power will give you a boat that will run but won't have the top end the dedicated race boats do. If you want to try to use lighter stuff, feel free. If that lighter stuff fails due to overloading, what can I say, that's the breaks of R/C boating
I am taking into consideration what you have suggested, as well as what my old racing friend on the east coast ( Don Ferrette) has suggested.
Like I have stated, I don't need a rocket just a boat that will get up on plane and throw up a rooster tail, if the boat only does 40 mph that's fine
for what I have intended it to do. Several years ago I set this exact boat up for a club member in stock built form with a K&B 67 nitro motor, very
heavy boat but with the nitro motor would run in the low 50 mph range on 65% nitro, but I am no longer into nitro boats, the reason being I am
looking to go electric. There is no longer a lot of the racing sites here in Louisiana and Texas that I used to run hydro's & mono's on so I will have
to have my fun at the local lake. I think under the circumstances electric is a more viable power source due to the advancement of brushless motors.
plus I don't have to worry about the noise factor to nitro related running.

Last edited by Bill Diedrich; 08-08-2019 at 03:46 AM. Reason: addition info
Bill Diedrich is offline  
Reply With Quote
Old 08-08-2019, 04:18 AM
  #14  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,742
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I'm sure that, between me, RPM and Don, you have some good options. When you get the boat done, be sure to post some pictures as I'd love to see them.
Happy Boating
Hydro Junkie is offline  
Reply With Quote
Old 08-08-2019, 08:19 AM
  #15  
Bill Diedrich
 
Bill Diedrich's Avatar
 
Join Date: Jul 2006
Location: Ventress, LA
Posts: 1,383
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Just dusted off an old box up on the top ridge shelf in my shop and came across 3 old cowl sets,
one of them is the AVL with the wings I got from Dick Caspari many moons ago, so that will be
used in place of the wooden parts in this kit. The other 2 I'm not sure what boat they are for, I
think one is for the Hawaii Kai, the other I'm not to sure of as I got them from Troy McIntyre,
close to 15 years ago.

BTW, Hydro Junkie do you know if anyone ended up with Troy's molds after his passing?
Bill Diedrich is offline  
Reply With Quote
Old 08-08-2019, 09:32 AM
  #16  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,742
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Rumor was that his molds sat in a storage shed at his mother's house for several years before someone in Texas agreed to meet the price the family wanted. I haven't heard of any parts being made using them since, if the rumor is true
Hydro Junkie is offline  
Reply With Quote
Old 09-09-2019, 07:07 AM
  #17  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Hydro Junkie View Post
Got any pictures of where you're at in the build? You may need to take the bottom off the boat to do the conversion you're looking at.
As for your original plan on using a CMB .67 green head, the boat was never designed for that much power and might cause issues when running. That said, it is very doable to get the boat running with that CMB but, as with all projects, there is a learning curve as well as a lots of testing
Ok Hydro, trying to toss some images here, but it looks like there is a point system I need to acheive 10, count 'em ten, so I think might bring be to 4...
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:08 AM
  #18  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

So i have a few images of the whole boat (Before final detailing), engine bay with the Green Head.....
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:19 AM
  #19  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

With the remote needle between the 10 oz.. tank in the nose.....
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:20 AM
  #20  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

All Acutech hardware, with a slip yoke I made for the drive line connection....
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:21 AM
  #21  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

All water proof servos, the rudder servo has the torque almost twice as much and the "quarter scale" servo they recommend for this hull...
I love tech advances...
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:24 AM
  #22  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

So I am looking for some input to flip this hull to elec/LiPo, and looking for any help with guidance. I think I can stuff in a 6S 5K mah with out any real mods to the nose, or may have to go 4s2p....
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:24 AM
  #23  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

OK, one more then I'm done "stuffing" my counts, sorry for the hassle you guys...
flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:42 AM
  #24  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Well let's see how this goes:





flycaster2 is offline  
Reply With Quote
Old 09-09-2019, 07:47 AM
  #25  
flycaster2
Thread Starter
 
Join Date: Sep 2010
Location: Moraga, CA
Posts: 16
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Hydro Junkie View Post
Got any pictures of where you're at in the build? You may need to take the bottom off the boat to do the conversion you're looking at.
As for your original plan on using a CMB .67 green head, the boat was never designed for that much power and might cause issues when running. That said, it is very doable to get the boat running with that CMB but, as with all projects, there is a learning curve as well as a lots of testing
Hey Hydro, here are some images.

C
flycaster2 is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service