Matt, Very nice work on your Abrams (nice website also).
On the EV amperage. The Cromwell is running 24v and I only have one 60A fuse in the circuit (in front of the controller). I've never stalled a motor or blown a fuse. I attribute that to two facts, my controller is current limiting and I have belts on my first stage reduction acting as a mechanical fuse. When building these things it's important to avoid high amperage conditions caused by a motor stall using techniques most appropriate for your mechanical and electronics mix. Steve Tyng On Nov 4, 2:26 am, "Chris. b" <[EMAIL PROTECTED]> wrote: > If you run the evs at 24v you will have a hard time stalling them on a > 9:1 ratio, your more likely to break your tracks or chains somewhere. > If you install belts you will never stall the evs under normal use. I > used to run evs 12v 9:1 with 60amp fuses, never blew one of them and I > didnt exactly take it easy on my tank. > > Chris. b > > On Nov 4, 9:43 am, "Derek Engelhaupt" <[EMAIL PROTECTED]> wrote: > > > Wire > > Gauge > > 00 awg 400 amps > > 0 awg 325 amps > > 1 awg 250 amps > > 2 awg 200 amps > > 4 awg 125 amps > > 6 awg 80 amps > > 8 awg 50 amps > > 10 awg 30 amps > > 12 awg 20 amps > > 14 awg 15 amps > > 16 awg 7.5 amps > > > These are the recommended maximum fuse ratings for the corresponding > > wire size. Using a smaller fuse than what's recommended here will be > > perfectly safe. > > > I got this chart off of an electronics website. These maximums are > > designed to keep the wire from burning up (ie: starting on fire). > > According to this chart, my fuses are too big for my wire size. The > > M-01 motors Joe sells have blown 30 amp fuses in a stall. I'm > > thinking I need to put some smaller fuses in my tank. Yes you EV's > > will have a higher stall current at 24V, but they should also draw > > less amps at 24V under the same load at 12V. > > > Derek > > > On Mon, Nov 3, 2008 at 3:37 PM, Matt <[EMAIL PROTECTED]> wrote: > > > > Well I thought that the speed controllers would be able to handle the > > > current more readily at 12 volts. As you can see, the tank is very > > > long and narrow, so it doesn´t do turns very well. at 24 volts, the > > > stall current is close to 200 amps. the speed controllers are only > > > rated at 120 amps continuous, and 200 amps for 2 seconds. The increase > > > in power would make the motors less likely to stall out, but to begin > > > with I just wanted a good, solid system to move the tank. > > > > But, in case I do want to upgrade the voltage, what fuses would I use? > > > I was thinking 120 amp, but I am no expert on this stuff. Its > > > definitely at the top of the list of upgrades, along with a suspension > > > system. > > > > Thanks for all of the imput, > > > -Matt > > > > On Nov 3, 11:59 am, "Derek Engelhaupt" <[EMAIL PROTECTED]> wrote: > > >> Great looking tank Matt. Just a few questions. What was the > > >> reasoning behind gearing the EV's so low? Just curious since most of > > >> the EV folks use a 9:1 ratio on them. Secondly, did you have a reason > > >> for going with 12V instead of 24V? I'm asking since the motors are > > >> more efficient at 24V. I would think that if you ran them on 24V with > > >> a 9:1 ratio, you would still be able to make your climbing goals... :) > > > >> Derek > > > >> On Mon, Nov 3, 2008 at 1:44 PM, Chris Malton <[EMAIL PROTECTED]> wrote: > > > >> > I have to say, I think it probably deserves its designation, even if it > > >> > wasn't ready for it. > > > >> > That is pretty cool. Well done Matt. > > > >> > Chris > > > >> > On 03/11/2008 15:55, Matt wrote: > > >> >> I think my Tank is finally ready for a designation number. You can go > > >> >> to my website atwww.freewebs.com/shootermiketocheckout the videos > > >> >> of it moving. > > >> >> Thanks > > >> >> -Matt- Hide quoted text - > > > >> - Show quoted text -- Hide quoted text - > > > - Show quoted text - > > --~--~---------~--~----~------------~-------~--~----~ You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [EMAIL PROTECTED] Visit the group at http://groups.google.com/group/rctankcombat -~----------~----~----~----~------~----~------~--~---
