Topic: 14.4V Brushed ESC for tug (Read 6893 times)

Jon · « **on:** June 05, 2016, 07:56:33 pm »

I know everyone has their preferences, but I'm after peoples experiences on higher voltage 14.4V (12 Cell NiMh) brushed speed controls.
I need bidirectional and instant reverse.
It will be powering a high quality geared 12pole 400 Can sized motor
Power is small only 2-3A Max.
Size is more or less irrelevant, I have lots of space in the tug.
Don't care if it's waterproof or not, I don't intend to sink.

Choice seems to be:
MTroniks
Electronize
eBay Special...

I've had bad experiences with the Mtroniks Viper15 (on 12V) in the past, so am reluctant to go MTroniks (got through 3 in quick succession)
So could people offer opinions of alternatives, or reassure me about a particular model of MTroniks suitable for 14.4V.
People keep talking about MicroGyros, but their web pages are down at present, so cant see if they offer a high voltage version.
All Comments welcome.

Jon

J.beazley · « **Reply #1 on:** June 05, 2016, 08:25:09 pm »

Quick question what tug are you using and what on earth is the motor in it to warrent 14 volts.

I would say Mtroniks 20amp esc as it can take the abuse from chucking the voltage full ahead to full astern with that sort of load running of 2-3amps. Whats the stall rate of the motor in question as that may well be another factor to consider when picking a ESC.

Jay

malcolmfrary · « **Reply #2 on:** June 05, 2016, 09:33:24 pm »

It is a bit of a struggle to see what advantage using 14.4 volts would be over 12 volts, unless there was a supply of free batteries available, say 7.2 volt ones that could be wired in series. Or 4S Lipos, but that would be 14.8 volts.
This https://www.mr-rcworld.co.uk/shop/variable-speed-controller-/ might be what you are looking for. Not excessive current handling, no BEC built in, but capable of high voltage.

Jon · « **Reply #3 on:** June 05, 2016, 09:53:43 pm »

Thanks Malcolm, interesting link, yes Im using salvaged sticks of 3 cells, and due to ballast and positioning I need to use even numbers. I ran on 7.2V today at the pond and it wasn't enough RPM, so next step is 14.4V, This should be fine, but if I need to go above this, then Ill need to change cells, as Its 1.5Kg for 6 cells (F cells) and Id be too heavy with 18 cells.

Jon · « **Reply #4 on:** June 05, 2016, 10:14:17 pm »

Quote from: J.beazley on June 05, 2016, 08:25:09 pm

Quick question what tug are you using and what on earth is the motor in it to warrent 14 volts.

I would say Mtroniks 20amp esc as it can take the abuse from chucking the voltage full ahead to full astern with that sort of load running of 2-3amps. Whats the stall rate of the motor in question as that may well be another factor to consider when picking a ESC.
Jay

The motor and combined planetary gearbox is out of a Sumake 7000 production screwdriver. Ive machined off one of the stages of the gearbox to speed up the shaft. But it still needs the voltage to up the rpm a little for the 2" 4 blade prop it drives. Ill grab a spare motor and check the stall current at 14V.
Ok thats one vote for MTroniks again, thanks.
Jon

Jon · « **Reply #5 on:** June 05, 2016, 11:11:08 pm »

Stall current is 14A at 14V convenient

Jon

malcolmfrary · « **Reply #6 on:** June 06, 2016, 08:34:21 am »

Just remembered a downside of that ESC. It has a soft start and stop. Mostly, thats a good thing, but where I was trying it, the soft stop did not help.
When repurposing batteries, it is OK to hack into the packs and extract the number of cells wanted. The linking tags are accessible enough and make good soldering tags. Two sticks of 5 should be quite possible.

Jon · « **Reply #7 on:** June 06, 2016, 10:23:59 am »

Hi, Yes, I noticed the soft start/stop. I was going to look into that a bit further.
The packs I have unfortunately don't have tags between the cells that I can see, even after removing the shrink.
I don't know how they have been assembled, but it looks like they are directly spot welded to each other.
The packs are made by Saft themselves, not by an after market assembler.

But yes I take your point, I could rebuild the packs even with some complication, but there not really a problem using 14.4V, and the ballast is about right.
I was just interested in getting peoples views on compatible controllers, as it's been some years and time may have gone on from Electronisze/MTroniks.
Always worth looking at the new options on the block.
Thanks for the reply.
Jon

aln101boat · « **Reply #8 on:** June 06, 2016, 03:37:22 pm »

Quote from: Jon on June 05, 2016, 09:53:43 pm

Thanks Malcolm, interesting link, yes Im using salvaged sticks of 3 cells, and due to ballast and positioning I need to use even numbers. I ran on 7.2V today at the pond and it wasn't enough RPM, so next step is 14.4V, This should be fine, but if I need to go above this, then Ill need to change cells, as Its 1.5Kg for 6 cells (F cells) and Id be too heavy with 18 cells.

I think you'll get a shock at how much difference each extra cell makes. doubling the voltage is likely to more than quadruple the motor revs

. I certainly wouldn't jump from 7.2 to 14.4. Halfway would make quite a difference.
Even numbers? Cant be a cat cause you only mentioned one motor. If you have to spread them out, put one stick in each side aft, and a third in the center forward? Whatever you do, I suggest you forget 14.4v.
Alan

Jon · « **Reply #9 on:** June 06, 2016, 04:00:08 pm »

The motor RPM changes very linearly with revs, so it will just about double. The revs don't drop under water load either, with the prop I have.
The Hull is not a cat no, but in essence I have two locations to nicely put the cells.
I'll upload a photo later.

J.beazley · « **Reply #10 on:** June 06, 2016, 04:49:48 pm »

Forgetting about voltage 14amps stalled is a lot for any 15amp esc.

A good 20amp plus esc would be recommended, if your not a fan of the Mtroniks check out the action range of Esc on componentshops website tried and tested hardware that pleases a lot on the forum.

Jay

Jon · « **Reply #11 on:** June 06, 2016, 08:43:25 pm »

Thanks Jay, yes 20A min would be good.
I had forgotten about component shop. I'll give them a look.
I do prefer non potted things, as if they do fail. I have some hope of repairing them.
I've just double checked my RPM and I get 750RPM at 7.2V, 1550 RPM at 14.4V, so I really am still taking low RPM due to the two stages of planetary box in the way.
Jon

Jon · « **Reply #12 on:** June 06, 2016, 09:02:23 pm »

Quote from: J.beazley on June 05, 2016, 08:25:09 pm

Quick question what tug are you using
Jay

Jay forgot to answer "what tug", this is a 1/8th scale motorflote.
Jon

Jon · « **Reply #13 on:** June 06, 2016, 09:23:51 pm »

Six cells in the port side of the Motorflote:

Subculture · « **Reply #14 on:** June 06, 2016, 10:14:31 pm »

Microgyros FR40. Good up to 28 volts, but run a separate receiver pack or switch mode BEC, becuase linear regulators are heavily pushed above 12 volts.

Jon · « **Reply #15 on:** June 06, 2016, 10:17:29 pm »

Where can you get details of the Microgyros FR40, or buy them for that matter? Microgyros.com seems to be out of action for a year, or they have the date wrong.
I run switch mode UBECs on everything, but thanks for the advice.
Rgds
Jon

Shipmate60 · « **Reply #16 on:** June 07, 2016, 07:53:01 am »

Give Mike a phone.
His number is: 0141 416 2001.

Bob

jarvo · « **Reply #17 on:** November 12, 2016, 07:24:59 pm »

Hi Mate, i use the Electronize ESC on 24volts, works very well, recommended with over 10 years use in many different models

Mark

Stavros · « **Reply #18 on:** November 12, 2016, 08:05:26 pm »

Have a look at the ACTion range of esc's

Dave

Subculture · « **Reply #19 on:** November 13, 2016, 12:19:10 pm »

Microgyros website has been down for a while, but mike is still actively making ESC's, and they are and always have been suitable for higher voltages.

He usually has a small stand at the international Model Boat show held this weekend, so you might catch him there this year? Failing that, pick up the telephone and speak to him.

https://web.archive.org/web/20130613063831/http://microgyros.com/

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Author Topic: 14.4V Brushed ESC for tug (Read 6893 times)

Stavros