Cookies used in this website are gluten free, wheat free and dairy free. By using this website you agree to our use of cookies. More Info
Guest
Login Below
Join Us On Social Media!
   
Get The Model Boats App!
Apple App Store
Android app on Google Play


Help Support This Website
£
or enter custom amount

(Non Contributor)

Help support this free
website and donate.



£285 a year is needed to keep the website and apps online. Please consider donating £5 or more to help towards these fees.
All donations are securely managed through PayPal. Amounts donated are not published online.

Many thanks for your kind support.

Model Boats Website Team


Donation History
August 2017: 9 people
July 2017: 16 people
June 2017: 8 people
May 2017: 8 people
April 2017: 23 people
March 2017: 9 people
February 2017: 12 people
January 2017: 15 people


Unique Visitors This Month

Website Members

Terms and Conditions
Privacy Policy
Advertising
Contact


Model Boats Website
Active Users (5)
Login or Register
To Remove This Ad

Login or Register
To Remove This Ad
>> Home > Forum > Electrical Related > Motor suppression
Motor suppression
(568 views)
Author Message
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
5th Jun 2017 11:24  
>> Permalink
mdlbt.com/29734

I have just installed an MFA 800 Motor in my launch CAROLINE. but I think it needs suppressing, what rating should I use please. Running on 12volt gell battery with old 40mhz radio and a VIPER MARINE 20amp speed control.
Any info would be welcome. Thanks Colin.


Fair winds and calm waters,
COLIN.
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
5th Jun 2017 11:59  
>> Permalink
mdlbt.com/29738

Hi Colin,
The website has info about this
https://model-boats.com/rc/motors/suppression

Capacitors should be easily available at Radio Spares etc; use only the flat ceramic types. Some model shops carry suppression pack with the 3 capacitors you need. Cheers Doug 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
5th Jun 2017 12:01  
>> Permalink
mdlbt.com/29739

PS: the effect is further improved by earthing the motor can to the propshaft if possible. 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
muddy
(Captain)





Forum Posts: 10
5th Jun 2017 12:08  
>> Permalink
mdlbt.com/29740

Hello Colin.. There was a very good description of motor suppression in the MMI plans handbook a couple of years ago..
Using Disc Capacitors, values were stated at 47 nf across the motor terminals, and 100 nf across each motor connection to the motor can, keeping the Capacitor tails ( wire ) as short as possible at the motor terminal end. As for voltage rating, a general rule of thumb is to double the operating voltage at least, in this instance i would use 50 volt rated capacitors.. Regards Muddy....

RNinMunich
(Fleet Admiral!)





Forum Posts: 639
5th Jun 2017 12:11  
>> Permalink
mdlbt.com/29741

Here you can find some useful cause and effect info! 👍
https://www.pololu.com/docs/0J15/9
Twisting the leads together is a good tip, I do it with my servo leads as well.
Technique is used in profi. telecoms installations, esp. on ships (my speciality for 30+ years!) Cheers Doug 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
5th Jun 2017 17:56  
>> Permalink
mdlbt.com/29769

Thanks guys, I will call at Maplins tomorrow and get the appropriate suppressors. It's good to know that help is so close at hand. The Worcester Model Boat Club open day on Saturday will be the relaunch day, as she hasn't seen water for nearly 20 years. Can't test beforehand as won't fit in bath. Will post pictures when we get home. Best wishes to all, Colin.


Fair winds and calm waters,
COLIN.
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
5th Jun 2017 21:51  
>> Permalink
mdlbt.com/29772

Hi Colin, glad we could help. Since you are using a 12V batt. make sure the capacitors are rated for at least 25V. 40 or 50V to make sure.
ON NO ACCOUNT USE ELECTROLYTIC TYPES WHICH ARE POLARISED (+/-) ON A REVERSIBLE MOTOR! Otherwise they can go off like mini mortar throwers!
Quite spectacular, creates a mini snowstorm. Used to do this deliberately in my test engineer days to scare the knickers off the girls in production dept. 😉😉
Re 'Close at hand'; this is relative these days (apologies to Albert E!), you are in Hereford, I'm in Munich! But still only milliseconds away! 😉
Looking forward to pics of the relaunch. 👍😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
6th Jun 2017 23:22  
>> Permalink
mdlbt.com/29849

Hi guys, after reading all your advice including muddy's pm. I've fitted the suppressors and earthed the motor can to shaft tube, then run the motor for 6 hours starting on 1.5 volts And working up by 1.5 volts every 20 minutes, plus running in reverse at each voltage step. Finally up to 12volts. No arcing and no interference. But while doing this I found another problem, the prop shaft was bent, it took about half an hour to true it up, now super quiet. I used Mitchell Marine Grease in the shaft tube. (Available at all good fishing tackle shops). Tomorrow I will try to do a load test in water if my grandsons paddling pool will take it as I want to know the run time on my SLA and gell batteries. Well that's it for tonight I'm pooped. Good night. Colin.


Fair winds and calm waters,
COLIN.
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
7th Jun 2017 05:46  
>> Permalink
mdlbt.com/29853

Mornin' Colin, glad it worked out 😊
Hang on tight during the load test 😉😎
Apropos fishing tackle shops; for the load testing on my Sea Scout, which is about to receive a brushless, I intend to tether it with a fisherman's spring balance so I can also see what thrust the motor/prop combination produces. Might help me to optimise the prop size. Cheers Doug


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
7th Jun 2017 08:19  
>> Permalink
mdlbt.com/29859

Morning Doug, will try my scales as I'm running a 75mm 4 blade prop. Thanks Colin.


Fair winds and calm waters,
COLIN.
muddy
(Captain)





Forum Posts: 10
7th Jun 2017 08:44  
>> Permalink
mdlbt.com/29860

Colin, the "pm" had me puzzled for a while, but now i have found the reason why, so apologies to all, this was not meant to happen, am still trying to find my way around the site... Please post it if you like, with apologies to all.. Regards Muddy....

RNinMunich
(Fleet Admiral!)





Forum Posts: 639
7th Jun 2017 08:54  
>> Permalink
mdlbt.com/29861

Wow! Big prop Colin. How big is the boat ??


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
7th Jun 2017 09:40  
>> Permalink
mdlbt.com/29864

Hi Colin, Don't worry, just found her on the site. Very nice looking boat 👍
Have lots of fun, Cheers Doug 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
7th Jun 2017 09:49  
>> Permalink
mdlbt.com/29867

Hi Colin, just had a look at the MFA RE800 motor spec.
I note the stall current is 25.9A!! 'Stall Current RE 800 at 12v = 25.9A'.
To protect your 20A ESC ensure that you have a 20A fuse in the motor positive supply lead!! Cheers Doug 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
7th Jun 2017 09:56  
>> Permalink
mdlbt.com/29868

Hi Doug, the prop looks a bit small, but the boat is 5 foot long, and 1.5 foot beam. Weight? Not sure yet, first sailing in 22 years. As been used for display at vintage shows for last fifteen. So family is excited to see how dads old boat goes, as none of my sisters ever saw it. Fingers crossed. By for now Colin.


Fair winds and calm waters,
COLIN.
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
7th Jun 2017 10:03  
>> Permalink
mdlbt.com/29869

Looking forward to the video!!👍
I'm in a similar situation with my old Sea Scout (at 24" mini compared to Caroline!) Built by Dad circa 1963, last sailed about 25 years ago, now being refurbed with brushless! Ciao Doug 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
7th Jun 2017 11:35  
>> Permalink
mdlbt.com/29872

Fused at15amps, as recommended by model shop that sold me the set up. Thanks Colin.


Fair winds and calm waters,
COLIN.
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
7th Jun 2017 12:19  
>> Permalink
mdlbt.com/29873

Good show👍 A rare beast these days - a competent model shop - esp. here in Germany 🤔
😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
8th Jun 2017 15:23  
>> Permalink
mdlbt.com/29941

Hi all, have just finished testing the Caroline. Dry weight including battery was 13.2 Kilos. placed in paddling pool and she sits nice and level, I attached a set of fishing scales to the transome and tethered them to bench at end of pool. Slowly increased power and at full throttle gave a reading of 7kgs on the scale, at half throttle still showed 5kgs and water was lifting over poolside. Although pool is only 1ft longer than boat enough power to lift bow, in fact she tried to climb out. So well pleased with results👍. Battery lasted 1.25 hours at half throttle.
So looking forward to her maiden voyage on Worcester Model Boat club open day, I feel like a 5 year old looking forward to xmas😊. My son is going to help me on the day as she's such a big lump, should realy have a slipway launch.
Hope some of you will be there to watch. Going shopping now, fire boat needs a new battery for fire fighting pump. Best wishes Colin. (photo WITH BLUE BACKGROUND was before refurb)


Attached Files - Click To View Large


Fair winds and calm waters,
COLIN.
RNinMunich
(Fleet Admiral!)





Forum Posts: 639
8th Jun 2017 17:16  
>> Permalink
mdlbt.com/29944

Hi Colin, Great 👍 reading that made me feel like a little boy again as well 😉 Glad you picked up on the fishing scales 👍 Gives me a datum for the the test with my Sea Scout -Jessica.
Looking forward to the video. Cheers Doug 😎


"Retirement is when you stop living at work -
and start working at living/boat modeling!" 舰队的海军上将 😉 Doug
colinhubbard
(Fleet Admiral!)





Forum Posts: 159
11th Jun 2017 09:28  
>> Permalink
mdlbt.com/30052

Well Doug, relaunch went well and first trip round lake showed I needed to re-balast,as she ploughed through the water. So after consulting others at lakeside I added another 12v 7ah battery (ballast only) and moved the drive battery back by a foot. Placing them side by side amidships. Now she sailed properly. Even pushed the dinghy with 1 man aboard up the lake. So all in all it was a great day will try and get pictures posted and video. Problem being it's all on wife's camera and haven't figured out how to put on PC yet. By for now got to go help grandson. Colin.


Fair winds and calm waters,
COLIN.