ESCs for Small Electric Models
 

Guys,

I have a number of plastic Lindberg ship models of various types. Most of them are the small (about 12" length) models that don't have a lot of extra space inside and can't carry a lot of extra weight. These are single-motor models and were designed for two AA batteries, You just set the rudder, turn on the motor, and let it go. Using modern 2.4 GHz receivers and sub micro servos, it would be easy to control the rudder. Motor control is another story. I've seen some small ESC's for brushed motors, but they are designed for airplanes, so they have no reversing capabilities. I was planning on using two 3.3V LiFe batteries to power the receiver and motor.

Does anyone know of a supplier for small, low current ESCs that have reversing capabilities?

Thanks in advance.

Bob

I share your fascination with plastic ship model R/C conversions and likewise hail Lindberg as one of the main suppliers of worthy conversion models. To date I have the Diesel Tug, Tuna Clipper, Shrimp Boat, North Atlantic Fishing Trawler (complete but de-engined right now), Minesweeper, Coast Guard Tug, Coast Guard Patrol Boat and a few other Lindberg kits I'm sure.

Right now I am looking at the cheap Chinese 10A Brushed ESC which are all over that popular auction site. Have not tested the one I've got but at $10 shipped, it is a very good deal. Here's what I came up with.

Thanks. Do these ESC's have reversing capability. or are they one-direction only?

Bob

P.S., I have the LST, LSU, LSD, LCVP, HMS Hood, Bismarck, Tirpitz, Blue Devil Destroyer, Troop Attack Craft, Shrimp Boat, and the Southern Belle paddle boat. I'm still hoping to find Fulton's Clairmont at a reasonable price. None of these have been "R/Ced" yet, which is why I asked the question about the ESCs.

Oh yeah, I have the LCT (or LSU), LCVP, Blue Devil but I think that's it. The Revell Firefighter is also a good one to get (19" long!) but I want to kitbash it into a freelance or navy tug.

Yes, these ESC have reverse capability but avoid the ones that say "with brake" as I think there's a built in delay between brake and reverse. Just enter "Brushed ESC" into the search on that aforementioned auction site and you should get many, many hits.

With the smaller Lindbergs there is the possibility of just butchering a (standard size) servo for its motor and electronic board, fully proportional forward and reverse, a lack of deadband, but do you sail your boat to look at it sitting there? Limitations are that power is the RX battery, usually 6v max. If running Lithium, a voltage regulator might be needed for the electronics, a voltage warning circuit will almost certainly be needed. The required extra electronics will eat into the weight advantage of Lithium, against the basic simplicity of NiMH.
Also - http://www.mr-rcworld.co.uk/index.php?productID=1010 Small, full function. Relay reverse, 2A, up to 30 volts (so the maker tells me)
The Chinese 10A ESC is good for up to 8.4 volts and has its own BEC. Its off position is heavily offset (probably designed by a Futaba user), the deadband is wider than normal, and seems to give more power in reverse.
If doing one with more than one motor, I would opt for a pair of these - http://www.action-electronics.co.uk/speed.php with one of the same company's mixers. They are a class act and simply work out of the box, but are strictly limited to a regulated 5 volts, or 4 NiMH cells. Works great in my minesweeper off 4 AA.

Maybe one of these? http://www.ebay.com/itm/RC-Submarine...item3f2a5ac0ec I don't know anything about them, but it does have F & R.

Indboat

Or one of these - http://www.ebay.com/itm/RC-10A-ESC-B...item3ccd039bc8
Looks like the same item at about 1/3 the price.

Guys,

I purchased several of the ESCs referenced by HARQUEBUS above. I haven't tried them in a boat as yet, but I did hook them up to a battery, motor, and receiver and they seemed to work nicely. There is a decent dead band around the point where you want the motor to be off so it should be easy to control the boat when "docking". They are very small and light and the price was right as well.

Bob

The downsides to those ESCs are that there is a distinct power bias between forward and reverse (put servo reverse on the TX to rev) and the neutral seems to be designed with Futaba in mind rather than the rest. Nothing major. BUT - don't run the battery too far down. They have a "feature" which cuts the ESC if the voltage drops too far AND DOESN'T RESET UNLESS POWER IS CUT AND RESTORED. Not a problem in a buggy, a major problem in a boat unless you have very long arms. I haven't determined whether it was something causing a high current or just the battery getting low, but I suspect the latter. On recovering the boat and switching off and on, everything worked fine, but its a big lake, so I called it a day.

There are also these FWD only models from Hobby King.
How can you beat it for $5?? I have bought and used several of them.
These are rated at 20 amps, the 30 amp model is $8.
http://www.hobbyking.com/hobbyking/s...USHED_ESC.html
Dave

I'll keep the battery voltage problem in mind. I usually try to insure that my batteries are not getting too low before I put the boat in the water again. I use LiFe batteries, and they hold their voltage until the point where they are almost completely discharged. That's good to maximize the power that they can deliver, but not so good if you are far out on the water and they start to go flat. I usually time my excursions so that I have a good idea that the battery still has plenty of juice left when I'm bringing it back to shore. My boats are all smaller and probably don't draw more than an amp when at full throttle, so the batteries last a long time before needing a recharge.

Bob

Yes but NO reverse does not improve confidence; there's times when reverse is a need and not a luxury. No reverse could mean your model not coming back to you in a worst case scenario. :) Guess one should avoid those scenarios at all costs.

Corsair-Fan (and everyone): keep us posted on your experiences with these ESCs. The more the better as an accurate consensus of opinion can be built around these inexpensive little units. Maybe they're not all lackluster in performance like mfr02 has reported. There's got to be some cheap, fully functional ESCs out there to fill the gap. I will also share as much info as I can. :cool:

I will definitely keep everyone posted on my experience with these ESCs. Unfortunately, the weather up here in the Northeast is not conducive to model boating right now, so it may be a few months before I get to put a model in the water to try it out. But when I do, I will let everyone know how I make out.

Bob

As far as butchering servos, most modellers seem to have a surplus or a steady source of old servos with worn out gears or such like that are worthy of converting or hacking. I do not so what would be a good off-the-shelf servo to use for the Lindberg Diesel Tug or the Shrimp Boat (for example)? I am leery of using one of the current glut of cheap Chinese servos (the ones that are ostensibly directly from mainland China) that have no name because of certain unknowns or they might not be up to the task, readily or easily disassembled, etc.

I've heard that a standard servo provides, possibly, the most ideal propulsion motor and one shouldn't go smaller (in servos) than that for the typical 12-17" converted plastic boat but I've heard 1/4 scale servos are sometimes also good. Am I correct in my thinking?

The 1/4 scale servos are pointed at a more restricted market and as a result the pricing suffers to the point where it is probably cheaper to use a "real" ESC and pick the motor you really want. When I started, mini ESCs were virtually non existent, decent quality mini motors likewise. Standard servos started somewhere above £11, but were an economical parts mine, so that's what I used. An alternative for a more powerful motor was to strip the case of a Hitec gold brick to lose the weight, one of my members did just that for his 1:60 PT boat, and hunted down a supplier of N cells (2/3AA, industrial). These problems are reduced with the availability of smaller ESCs and lithium batteries. Cost then was roughly comparable with todays price for a 1/4 scale servo.
My servo supply for years past has been a UK dealer, Howes of Oxford, who have had a "special" of 4 Acoms servos for £16, £ 4 each. Yet to have a problem. I suspect that the no-namers are ones that do not have a badge. I would also guess that the only suspect bits will be the gears and maybe the pot. If the thing is going to be gutted, neither matters - the gears are discarded to the spares box, the pot, once set, is unlikely to be moved, and its movement that causes the wear.

These or on the e-*bay now rated at 20 amps:
http://www.ebay.com/itm/ESC-20A-Brus...3255a6&vxp=mtr
Dave

They are all rather exciting kits. The Blue Devil is a must-have on account of the size (and the whole gimmick of the thing) and despite there being better alternatives currently available (Revell 1/144 Fletcher, only slightly smaller but better details). I'm not too keen on the Lindberg Hood/Bismarck/Tirpitz because of their inherent inaccuracies (too toylike) but the Blue Devil has those in spades so I am admittedly a little hypocritical there; guilty as charged. :o I rather chose the die hard Tamiya Bismarck and Missouri (one of each) for battleships in 1/350 scale.

Anyway, this is not meant to steal your thunder but I've seen a recent conversion of the Lindberg Southern Belle which I thought I would never see. This was seen not long after I became acquainted with the existence of the kit, matter of fact, but it just goes to show that knowing the extent of the entire Lindberg motorized boat kit lineup is, perhaps... unknowable. ;)

** The Troop Attack Craft or LCI is a rare one--you must be quite the collector. Also seek ye out the USS Carronade or "Bobtail Cruiser", another oddball but goodie...;)