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So, I finally got to run my Spartan a few times this past weekend. Overall things went very well, with only a few technical difficulties.
No amazing revelations, most of what I experienced has been documented already.
I was running by myself, so sorry, no videos and only a few boring pics confirming temps etc.
Most of you know my setup from following my threads the past few months, but here is a quick recap of the key modifications for those who are new here.
-Tacon 3674 1700kv motor with upgraded aluminum cooling jacket.
-T180 ESC set at 15* timing advance
-Prather S215 prop, sharpened polished and balanced
-Additional water pick up mounted on Trim Tab Adjuster
- Jeff Wohlt .150 flex cable and upgraded collet.
- MaxAmps 6500mah 3S 150C and Turnigy Nano tech 5000mah 3S 45C batteries
First run:
Water was very smooth and calm, and I started out with batteries full forward, the boat ran extremely stable but top speed according to Eagle Tree GPS was only 47kph (29 mph). I wasn't timing the runs but I'm guessing about 5-6 minutes on Maxamps 6500mah 3S batts before hitting lvc.
I had excellent water streams coming out of both outlets, so the modified rudder,and trim tab adjuster water pick up, work well.
The boat had a lot of torque roll to the right.
On subsequent runs I worked the batteries toward the stern, and also made minor adjustments to the right trim tab to try and correct for the torque roll. I also found the strut had a wee bit of negative trim, even though I thought I had it set neutral. I adjusted it slightly positive.
As I worked the batteries toward the back, the dreaded death wobble reared it's ugly head. My best recorded speed was 64.5kph (40 mph) with the batteries all the way back, but the chine walk was severe enough I wasn't able to run WOT.
I found the best running was with the batteries at the mid point. Only minimal chine walk, and still hitting 62 - 63 kph (38-39mph) at WOT with a good stable ride.
I know I can squeeze more speed out of this configuration, just need to settle down the chine walk first.
The last couple runs I pulled the liner out of the stuffing tube to see if that would help the torque roll, it didn't eliminate it, but seemed to help a bit. Hard to say for certain though, the water conditions were a bit rough on Tuesday and the boat was hopping around a fair bit.
I headed to the lake Friday and spent part of the day running the Spartans and my other boats, then headed back to town for the night. When I left for the lake again Saturday to spend the remainder of the long weekend at the cabin, I somehow managed to leave the eagle tree sitting on the table, therefore I don't have a lot of eagle tree data to evaluate yet. However temps were consistently in the mid 30 *C range (95*F) on the motor, esc and batteries, with the water temp at 10*C (50*F). Amp draw was spiking 120-140, but seemed to average around 50-60 amps.
Quirky LVC
I found the lvc on the T180 a bit quirky.
Originally had lvc set at 3.2v cut off. First two sets of batts came off showing just over 3.7v residual, but only 10-15% charge capacity remaining.
Changed the lvc setting to 3.4v for the next two runs and it was just about perfect, high side of 3.7 volts residual, and about 22-24% charge capacity remaining.
Then the next few runs the lvc (still set at 3.4v) was kicking in after only a minute or two of run time, with 75-80% charge remaining in the batts. I checked everything over thoroughly, but could find nothing that may have been causing the issue, so set the lvc back down to 3.2 volts.
The next few runs were better, but still short. Residual voltage over 3.8v with 50 -55% charge capacity left.
The last couple runs I lowered the lvc to 3.0v. The run times were OK, residual voltage was over 3.7v, and 35-40% charge remaining in the batts.
I plan on leaving the lvc at 3.0v for several runs before lowering it any further to ensure it is stabilized. (unless it starts drawing the batts too low again, in which case I will increase the lvc set point).
I was running all brand new batteries, so that may have had something to do with the erratic lvc behavior until they had a few charge cycles on them??
Next time out
I will be sure to have the Eagle Tree with me.
I will start experimenting more with tweaking the set up and will run a couple different props to see what the results are for amp draw, etc.
Overall it was fun to finally get back on the water after a long winter. The top speeds were a bit disappointing, but with a bit of tweaking and finding the right prop for this setup, I think the Spartan's will provide a lot fun for us this summer.
Kevin
PS my daughter was away on a school trip and not with me at the lake, so we didn't run her boats, but her Spartan is setup identical to mine so i suspect results will be similar.
No amazing revelations, most of what I experienced has been documented already.
I was running by myself, so sorry, no videos and only a few boring pics confirming temps etc.
Most of you know my setup from following my threads the past few months, but here is a quick recap of the key modifications for those who are new here.
-Tacon 3674 1700kv motor with upgraded aluminum cooling jacket.
-T180 ESC set at 15* timing advance
-Prather S215 prop, sharpened polished and balanced
-Additional water pick up mounted on Trim Tab Adjuster
- Jeff Wohlt .150 flex cable and upgraded collet.
- MaxAmps 6500mah 3S 150C and Turnigy Nano tech 5000mah 3S 45C batteries
First run:
Water was very smooth and calm, and I started out with batteries full forward, the boat ran extremely stable but top speed according to Eagle Tree GPS was only 47kph (29 mph). I wasn't timing the runs but I'm guessing about 5-6 minutes on Maxamps 6500mah 3S batts before hitting lvc.
I had excellent water streams coming out of both outlets, so the modified rudder,and trim tab adjuster water pick up, work well.
The boat had a lot of torque roll to the right.
On subsequent runs I worked the batteries toward the stern, and also made minor adjustments to the right trim tab to try and correct for the torque roll. I also found the strut had a wee bit of negative trim, even though I thought I had it set neutral. I adjusted it slightly positive.
As I worked the batteries toward the back, the dreaded death wobble reared it's ugly head. My best recorded speed was 64.5kph (40 mph) with the batteries all the way back, but the chine walk was severe enough I wasn't able to run WOT.
I found the best running was with the batteries at the mid point. Only minimal chine walk, and still hitting 62 - 63 kph (38-39mph) at WOT with a good stable ride.
I know I can squeeze more speed out of this configuration, just need to settle down the chine walk first.
The last couple runs I pulled the liner out of the stuffing tube to see if that would help the torque roll, it didn't eliminate it, but seemed to help a bit. Hard to say for certain though, the water conditions were a bit rough on Tuesday and the boat was hopping around a fair bit.
I headed to the lake Friday and spent part of the day running the Spartans and my other boats, then headed back to town for the night. When I left for the lake again Saturday to spend the remainder of the long weekend at the cabin, I somehow managed to leave the eagle tree sitting on the table, therefore I don't have a lot of eagle tree data to evaluate yet. However temps were consistently in the mid 30 *C range (95*F) on the motor, esc and batteries, with the water temp at 10*C (50*F). Amp draw was spiking 120-140, but seemed to average around 50-60 amps.
Quirky LVC
I found the lvc on the T180 a bit quirky.
Originally had lvc set at 3.2v cut off. First two sets of batts came off showing just over 3.7v residual, but only 10-15% charge capacity remaining.
Changed the lvc setting to 3.4v for the next two runs and it was just about perfect, high side of 3.7 volts residual, and about 22-24% charge capacity remaining.
Then the next few runs the lvc (still set at 3.4v) was kicking in after only a minute or two of run time, with 75-80% charge remaining in the batts. I checked everything over thoroughly, but could find nothing that may have been causing the issue, so set the lvc back down to 3.2 volts.
The next few runs were better, but still short. Residual voltage over 3.8v with 50 -55% charge capacity left.
The last couple runs I lowered the lvc to 3.0v. The run times were OK, residual voltage was over 3.7v, and 35-40% charge remaining in the batts.
I plan on leaving the lvc at 3.0v for several runs before lowering it any further to ensure it is stabilized. (unless it starts drawing the batts too low again, in which case I will increase the lvc set point).
I was running all brand new batteries, so that may have had something to do with the erratic lvc behavior until they had a few charge cycles on them??
Next time out
I will be sure to have the Eagle Tree with me.
I will start experimenting more with tweaking the set up and will run a couple different props to see what the results are for amp draw, etc.
Overall it was fun to finally get back on the water after a long winter. The top speeds were a bit disappointing, but with a bit of tweaking and finding the right prop for this setup, I think the Spartan's will provide a lot fun for us this summer.
Kevin
PS my daughter was away on a school trip and not with me at the lake, so we didn't run her boats, but her Spartan is setup identical to mine so i suspect results will be similar.
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