I am in the process of completing a Robbe Happy Hunter. I tested the main drive motors today and they make a weird variable frequency noise (best way to descibe it but it may be known or called something else) at the lowest end of the speed range. It also vibrates when in the water at slow speeds. I am using a Model Control Devices SC480 controller with a pair of Robbe 755/40 drive motors that are set up for direct drive per the Robbe plans. I set everything up per the contoller instructions and have tried both 6 and 12 volt power systems but the noise persists. It is fairly loud and I need to be able to operate at the lower speeds for a scale tug speed. The noise almost drowns out my sound system. Any ideas are greatly appreciated.

MCD and Vantec do that...

They just do... Not a lot that can be done about it.
At least nothing I have heard about..[]

Hi Knight Star,

The only way around the wining of the ESC, audible in the motorwindings, is using an ESC that has a variable frequency range; high in the low rpm's, so the motors run silently and lower in the higher rpm range, in order not to compromise efficiency.

These guys have a few:
http://modellbau-regler.de/xtcommerc...mj3jqou7of1387

You can mail them in English, if you want more information, as the site is only in German.

Regards, Jan.

I have an esc mcd 480 also, it wines when set on high and the motors make a knocking noise when it is set on low frequency, so I ran my 3 12v 700 Graupners on 3, 40$ Pro boats, on 12 volts. I am also running 2 12v Graupners on "one" 40$ pro boat esc, and it only gets a little hot, I will sell the mcd 480 to anyone for $90.

The whining is down to the way that ESCs work. The vibration is probably down to alignment of motor and propshaft.

Thanks for the help to this point. I have tried several ESC's since then and here is what I have found. All of these ESC's performed the same way whether the motors were in or out of the boat. This helped rule out the motor/drive shaft alignment issues. Also, these ESC's may work in other applications but below is how they worked in my boat and motors with a 12 volt supply battery.

Model Control Devices SC480 - I am still scratching my head why this will not work like I have heard. I sent the controller back to Dan at MCD and he has been more than helpful. He is going to do some work on the ESC and see if he can improve the performance.

Novak Super Duty XR - Controlled the motors very smoothly at both low and high speeds. You can make the motors crawl at very low speeds and hardly any whining from the controller. The only annoying feature is how Novak has the "brake" in this ESC which can not be disabled. You have to stop in neutral before advancing into reverse so that the motors sense they have no load on them and then it will allow you to use reverse. A little tricky for docking applications but it could be done.

Pro Boat Blue ESC - Not sure of the model number but it is anodized blue aluminum. It was only $40 so I thought I would try it out. This would not control very well at low speeds. Not good very attempting to make slow maneuvers. I will not be using this one.

Mtroniks Viper 40 - This ESC had great high and low speed control but the whining from the motors was just about intolerable. I was very disappointed with this one as I had heard great things from a lot of sources. This will not be one of my options.

Anybody have experience with the VanTec or the bigger Robbe line of controllers? I may try one of them next. After all is said and done I will have a few ESC's I will need to sell.
Thanks again.

I encountered the same problem with the Van Tec Speed controler. I called and spoke to the owner and he told me thats the way they are. He wouldn't do any thing for me except charge me a 20% restocking fee. They don't say anything about making noise in their ads. I guess you learned the hard way like I did and I hope it helps others to avoid this pitfall. I use Astro Flite Model 208D speed controls and they are great. Excellent low speed control and no noise what so ever. You can watch the prop turn on my large tug at slow speed. They can handle 30 Amps. and you can go to 24 Volts if you want. Many of my boat club members are also using them. Some of the guys use the proboat controlers on 6 Volts and get good low speed control but not on 12 Volts. I hope this helps Captain Bill

Thanks for all the information. As it turns out I purchased the Astroflight that Captain Bill recommended and that ESC worked just great. Great low speed controll and no noise. Onto the rest of the build completion.

Noise is subjective, it means different things to different people. What some people find objectionable may not be all that objectionable to me. Considering my hearing, that isn't saying much!
I haven't found any ESC yet that didn't make some noise, not too much, but still does make a sound. I've also never experienced a 'full sized' boat that didn't make some noise either. Unless it's really, really noisy and it really 'bothers' you, just tell people that's how it's supposed to sound. It's that super-duper fuel efficient unbelievable gas mileage motor in the thing! NO, you can't see it, it's secret!
- 'Doc

Hey Captain Bill, who sells the Astro Flite Model 208D? Very soon I'll be in the market for a speed control and that one seems to be a good candidate based on your evaluation. Also, what kind of tug is it and what motor are you using? (just doing a little research). Thanks

Ken

Ken,
I purchased my 208D from Tower Hobbies.

Ken, I purchased mine from Tower Hobbies also. I think that I have about 12 of them now and they all work great. I will try to post a picture of one of my tugs that I use the 208D in. It's a 53" tug with an Astro Flite 40 with 2:1 gear turning a 4" wheel. If the pictures don't show up you can go to my boat club web site (www.waveblasters.org) and check out the pictures in the gallery. I hope this helps you. Captain Bill