Best budget esc for 6 volt 7 amp Decaperm geared motor

[Ian Riddick 1Participant @ianriddick1]

Can anyone help me in choosing the best budget esc for my 6volt 7amp Decaperm geared motor. The Decaperm is installed in a model minesweeper and originally powered from a 6volt lead acid gell battery, via a Bobs models resistance board which has now gone to heaven.

Ian

[Ian Riddick 1Participant @ianriddick1]

The esc is to replace an old 8amp bobs board

[ashley needhamParticipant @ashleyneedham69188]

Ian. I use M’tronics esc’s. A Viper marine 15A one would do you ok.

Not saying they are the best, but they are a reasonable price and small enough.

Ashley

[Colin BishopModerator @colinbishop34627]

The Viper 15 is currently over 30% off at Howes Models. I've just bought one. Came the next day.

**LINK**

Colin

[Ian Riddick 1Participant @ianriddick1]

Ashley, thanks for the reply. I do have an Mtroniks 15 amp speed controller in another boat which I could remove and use. I have also seen one on Modelsport ,the sniper RV-20 made by Mtroniks for modelsport at £16.99. The esc is to power a geared 6 volt Decaperm with a 6 volt lead acid gel battery. All this in a 48inch wooden minesweeper the only change to the original running gear set up will be the speed controller.

I found out on my boat that has the Mtroniks speed controller in it that if I used the BEC connection on the speed controller and the voltage dropped below a certain point the speed controller stopped working. I overcame this by using a separate battery pack for the receiver.

Ian

[Ian Riddick 1Participant @ianriddick1]

Thanks Colin I will look into that.

Ian

[Colin BishopModerator @colinbishop34627]

The Viper 15 instruction sheet stipulates an input between 6v & 12v. so it is possible that a partially discharged 6v gel cell might affect the BEC voltage to the RX. Mine is being used with a 7.2v NiMH pack which has a flatter discharge curve than a lead acid so hopefully it will work OK.

Colin

[ashley needhamParticipant @ashleyneedham69188]

Good call Colin. Bargain at that price.

We have been building….”things” …at the park here using small brushless motors lately and these are really cheap…even from a U.k supplier, a 28mm outrunner and esc can be had for about £12-£16. Downside is they are aircraft esc so forwards only but if that’s OK, you are quids in.

Ashley

[Malcolm FraryParticipant @malcolmfrary95515]

When using anything involving a BEC that the voltage regulator almost always works by losing some voltage, some more than others. When the supply voltage drops too low, different ones react differently. Usually the output voltage drops, sometimes, and it might depend on the load, it cuts off. Some radios can tolerate a bit of voltage drop, some don't and switch themselves off until they get the required voltage back. There are BECs out there that are able to step up from a lower voltage as well as step down, but they are "exotic" and therefore normally expensive, and don't get used in low cost products, or products like RC gear where price is important.

Using a separate battery gets round marginal voltage supply problems as long as the red wire from the ESC to radio is disconnected. A BEC trying to charge a battery normally does neither the battery nor the BEC any favours, some BECs do not respond well to having a higher voltage battery connected to their output.

A 7 Amp motor will only draw 7 Amps under the right load conditions. A resistance controller needs to be well matched to its motor under the assumed load. An ESC is less particular. What will drive a lot will just as well drive a little. While the 7 Amp motor might only rarely actually draw 7 A, it is usual practice to double that figure and pick the next higher rated ESC. So 15A is a good start, but any higher rating will work as well, with the exception of the "320A" ESCs which are widely pushed on t'interweb.

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