Re: [electricboats] Thunderstruck

Ø  The ME1616 motor I'm told has max rpm of 1800rpm at 48V although Thunderstruck have unconfirmed feedback from a customer that 2200rpm has been achieved.

 

This low of an RPM for the ME1616 (or most of the others for that matter) does not make sense---unless the motor is not electrically wound for operation at 48v or thereabouts.

Looking at a variety of sites for specs on the ME1616 doesn't reveal much of an answer.  One site noted a 'max RPM' for the motor itself as 6000RPM.

 

So the ME1616 motor itself, if driven with the right voltage certainly is capable of RPM much greater than 2000RPM and perhaps as high as 6000RPM.  Highest efficiencies for sure are at higher voltages as appropriate for the windings.

 

Now, on Thunderstruck's site, there's a dyno data chart for their ME1616 configuration:

http://www.thunderstruck-ev.com/images/companies/1/ME1616%20Dyno.jpg?1515709005012

 

This data is for a nom. constant 72vDC with motor current and load torque ramping up to the right.

For this curve, at max power (8.7kw), current (134amps), torque (22Nm) all for constant 72v and 3800RPM or so.

 

So what if this same motor is used at 48vDC?

Open Loop Speed ~ 2533RPM (3800RPM * 48/72)

Max Torque (@134a) ~ 15Nm

 

The shame is that by using a motor designed for 72vDC, you are giving up 1/3 of its power potential by running it at 48vDC.  Still, if it affordable and achieves the goals, then it's great!  I ran my brush ETEK at 36v for 10 years before running it on a 48v pack. J

 

In case this helps…

 

-Myles Twete

 

 

From: electricboats@groups.io [mailto:electricboats@groups.io] On Behalf Of stewart.reed@free.fr
Sent: Sunday, November 15, 2020 12:43 AM
To: electricboats@groups.io
Subject: Re: [electricboats] Thunderstruck

 

Thanks all for the feedback. I decided to follow the advice and use belt and toothed wheels to give me flexibility. I also have a variable pitch 19" prop so have adjustment there.
The ME1616 motor I'm told has max rpm of 1800rpm at 48V although Thunderstruck have unconfirmed feedback from a customer that 2200rpm has been achieved. Will experiment once installed and happy to share if anyone interested.
I also checked kit elec shop . com - they have very similar kits to Thunderstruck. However I found Thunderstrucks prices better even including shipping, which was incredibly quick.
Now to get the bracket made and install over the winter ready for testing in the spring.