Advise sought

[ronin4740]

I participated in the EF-1 Race in Davis and am curious if another Castle Creations user might take a look at the logs from my ICE 75 and let me know if the RPM and battery voltage look typical or if there might be room for improvement.

Using a HK NTM EF-1 motor, ICE 75 on High Timing and China Hobby Line 40C 2700mAh 4S packs.

Thanks!

Static image of data from heat 1

[splatt]

I tried high timing once, first heat of last years NATS, big mistake. Man it was slowww. I would try it again on stock timing. I heard a noticeable difference changing it back. Cooling is key too. Find Jim Katz's articles on RC groups for ideas to keep the speed up in the later laps. Cycling or using the battery before hand seemed to make a difference as well, the first run of the day on a pack seemed slower to me.

After that, I' try another battery pack. I have one of those in-line amp/watt checker things, and I was seeing upper 50's to 60 amps with a Castle 75 and an OS motor with LifePower lite 4S 2500-2600? batt. Your batteries have to be able to dump current when asked and a motor/cooling combination that can shed the heat created.

[ronin4740]

Thanks. I'll give stock timing a try. The Nemesis I ran has plenty of cooling - I even went as far as to buy a vented Tru Turn spinner for it...

If you happen to have the link to the thread Jim commented in or the article could you drop it in here? Also if you happen to have a link to the batteries you're using... I don't mind spending a bit more $$$ to get the speed to the point where the airframe is competitive. Just trying to avoid spending what Thunderpower wants for G8 packs....

[splatt]

Jim's Nemesis thread shows what I love to be able to do. I did open the firewall and outlets on my Proud bird and made a balsa ramp to funnel air from the chin inlet upward to the opening of motor. It's a long winter up here, gotta do something to satisfy the BS that floats thru my head.

Lookie-here >> http://www.rcgroups.com/forums/showthread.php?t=1980364

[ronin4740]

Thanks! I'm subscribed to the thread but had forgotten that Jim was the thread starter. His work on the Nemesis is outstanding! Always worth another read through!

`

[tomdooly]

I compared your data with data I collected with my CC Edge Lite 75, OS motor and two different Nano-Tech 2650mah 35-70C batteries in my Proud Bird. My data was static data (not in the air) taken to compare my two batteries. WDR data is your data from the Woodlands-Davis Race, and Bat1 and Bat2 are from my two battery measurements. "O" time is at low throttle, and numbers are the averages of ten data points that are collected every second at full throttle.

Volts Amps kRPM
Time sec WDR Bat1 Bat2 WDR Bat1 Bat2 WDR Bat1 Bat2
0 16.54 16.54 16.69 0 0 0 0 0 0
10 13.93 14.81 14.66 53.27 59.93 58.05 14.031 14.831 14.853
20 13.49 14.44 14.3 47.23 56.66 55.06 13.956 14.461 14.468
30 13.58 14.35 14.22 47.15 55.86 54.42 13.962 14.354 14.354
40 13.76 14.23 14.22 47.14 55.06 54.5 14.029 14.29 14.29
50 13.71 14.19 14.2 47.8 54.66 53.94 14.023 14.207 14.207
60 13.7 14.19 14.02 47.64 54.02 53.62 14.029 14.145 14.145

Your data shows 0.3-0.9 volts lower than mine, along with correspondingly less current to the motor. This might be caused by a slight voltage drop across the battery-ESC connector. What type of connector are you using? I am using the HXT 4-mm bullet connectors in the red shell.
I have this data plotted on an Xcel spreadsheet, but am not sure how to attach it. Let me know if you have any questions or comments.
Tom

[tomdooly]

Sorry about the table format.....
Here is the Xcel spreadsheet...

[ronin4740]

Thanks for the reply. I tested again with Dynogy 65C packs and saw the same or really close to the same voltage levels. I think I'm going to swap the Turnigy NTM motor out for a Brodak or GP EF-1 motor and see if the numbers come back up.

I'm using Deans connectors but am thinking about swapping them out for XT60's or XT90's. I have a bunch of XT60 connectors but would have to order the XT90's. I believe I read somewhere that the voltage drop across the XT60's is lower than it is across Deans.