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

Dumas 1/8 Scale Hydro:

Notices
Speed - Electric For all your electric boating needs.

Dumas 1/8 Scale Hydro:

Old 01-11-2020, 07:44 AM
  #1  
Mikel1
Junior Member
Thread Starter
 
Join Date: Jan 2020
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default Dumas 1/8 Scale Hydro:

Building Dumas 1/8 Scale Hydro and thinking I might want to go electric if someone could advise me on motor size, battery's, and esc to use.
Amy information would be greatly apprehended.
Old 01-14-2020, 08:22 AM
  #2  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,929
Likes: 0
Received 3 Likes on 3 Posts
Default

Here is a cut and paste from the R/C Unlimiteds rule book. Everything listed has been used in competition so I know it all works.
Power and drivetrain
a. Approved motors
i. NEU 1527 1.5Y 850KV
ii. HET Typhoon 700-98 840KV
iii. Turnigy SK3-3994 850KV
iv. TP 4040 10Y 830KV
b. Twin motors are not allowed
c. Drive line: either cable or hard shafts may be used, no gear boxes allowed.
d. Any propeller may be used up to maximum of 57MM in diameter.
2. 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.
3. 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.

I'm going to throw a couple of questions at you:
1) Have you already started construction?
2) Is this your first boat?
3) Are you in an area that has other boaters that can help you if needed?
Old 01-15-2020, 01:59 AM
  #3  
Mikel1
Junior Member
Thread Starter
 
Join Date: Jan 2020
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Hydro Junkie View Post
Here is a cut and paste from the R/C Unlimiteds rule book. Everything listed has been used in competition so I know it all works.
Power and drivetrain
a. Approved motors
i. NEU 1527 1.5Y 850KV
ii. HET Typhoon 700-98 840KV
iii. Turnigy SK3-3994 850KV
iv. TP 4040 10Y 830KV
b. Twin motors are not allowed
c. Drive line: either cable or hard shafts may be used, no gear boxes allowed.
d. Any propeller may be used up to maximum of 57MM in diameter.
2. 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.
3. 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.

I'm going to throw a couple of questions at you:
1) Have you already started construction?
2) Is this your first boat?
3) Are you in an area that has other boaters that can help you if needed?
Hydro Junkie: Yes I have started construction. The hull is about 3/4s done with the bottom complete. I have built boats before but much smaller. .21 tunnel, and a .20 rigger. As far as other boaters in the area I would have to drive about 40 miles to get hel0.
Old 01-15-2020, 01:11 PM
  #4  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,929
Likes: 0
Received 3 Likes on 3 Posts
Default

Okay, I just was going to make a few recommendations on your build. If you're interested, let me know but, as someone that's built boats before, you may have already included some of them.
Old 01-16-2020, 12:59 AM
  #5  
Mikel1
Junior Member
Thread Starter
 
Join Date: Jan 2020
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Hydro Junkie View Post
Okay, I just was going to make a few recommendations on your build. If you're interested, let me know but, as someone that's built boats before, you may have already included some of them.
Always interested in recommendations. I have learned in the past with hubby's it is always a good thing to get any help you can. Thanks.
Old 01-16-2020, 07:44 AM
  #6  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,929
Likes: 0
Received 3 Likes on 3 Posts
Default

First off, Dumas boats are seriously overweight. To get it to run, you need to lighten it as much as possible, especially in the back of the boat. Here's a link to a picture of a Dumas sport 20 Pay'N Pak frame where I made some major strides to get it light:
https://www.rcuniverse.com/forum/att...1&d=1492980724
Next, move the weight(i.e. batteries, radio gear, etc) as far forward as you can. This will let the rear of the boat "fly" while keeping the front on the water. You will notice, in the picture linked below, the radio and engine are both at or forward of the sponson transom:
https://www.rcuniverse.com/forum/att...1&d=1492985226
Hope that helps a bit

Last edited by Hydro Junkie; 01-16-2020 at 07:47 AM.

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.