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View Full Version : Datalog from swordfiish 240....rpm seems low?



kfxguy
01-04-2015, 09:42 PM
Ran my daytona for the first time today. Was pretty dissapointing despite the fact its not tuned in nor did i have a good prop on it. I was in a very small pond also, but i did blip the throttle a few times to full throttle and the log showed that. The highest rpm recorded was 35k. Its got a neu 1521 1860kv on 6s. 443 cnc prop. The prop was running kinda deep in the water which may be a problem, but the top speed was 38mph. Pretty dismal, lol. I'm not really concerned with the speed, as that will get better as i get everything lined out, what concerns me is the low rpm recorded. It did pull a max of 227.9 amps. think its due to the prop being too deep? the strut is set like this: sitting flat on table the bottom of the strut is 1.5mm lower than the lowest part of the rear sponson. I have my rivercat set like this, but the shape of these sponsons are totally different so i expect strut setting to be different too. heres the log, what do you think?

126340

kfxguy
01-04-2015, 10:54 PM
I may have found the problem. I know it showed 100 percent throttle in the datalog, but out of curiosity, I ran another datalog, making sure all parameters were correct. I ran it on 4s just to see. Max throttle was 56%. Then I changed the throttle travel on my transmitter from 100% to 150% (remembering some people had this issue). Then I ran another data log. Current was lower, it got full throttle and max rpm's was 29625rpm . That's right in line with what it's supposed to be. Voltage at that point was 15.8v x 1860kv equals 29,388rpm which is almost right on the money. Hopefully this was the issue.

srislash
01-04-2015, 11:06 PM
Is bet you nailed the problem Travis. A 1521 should have no issue spinning a 443 even fully submerged

kfxguy
01-04-2015, 11:18 PM
Is bet you nailed the problem Travis. A 1521 should have no issue spinning a 443 even fully submerged

i know, the thing that bothers me is the datalog i first pulled when i got home showed 100% a points in the log, but I was unable to duplicate 100% throttle on the bench. I held it wide open for a few seconds (low voltage of course) and the most it recorded was 56%. Changed the travel to 150% and it showed 100% every time i pulled the tigger wide open. Weird i guess. I think the drive dog was hitting the strut too. Something I noticed, I had about a 2mm gap. If i pushed the shaft in, it went in about 1mm, which left about a 1mm gap...and then you have to think about cable shrinkage under load. ( I'm thinking this is the cause of the high amp load) The 1mm travel was because the motor had a spring washer at the rear bearing. It came from neu like this. If I remember correctly, the spring washer is supposed to go in the front of the motor. I moved it to the front, re_shimmed it and the motor even sounds better. I dunno. It'll be a process I'm sure getting this thing where i want it.

rickwess
01-05-2015, 09:10 AM
Since you have the USB Linker software working, update the firmware on the ESC and the throttle issue will be solved without having to change the travel settings on your transmitter.

kfxguy
01-05-2015, 09:22 AM
Since you have the USB Linker software working, update the firmware on the ESC and the throttle issue will be solved without having to change the travel settings on your transmitter.

I'll try that. No idea how to update it tho. Lol

rickwess
01-05-2015, 09:37 AM
I'll try that. No idea how to update it tho. Lol
Tab 5 of the Hifei software.

You can download the latest firmware from HiFei (http://www.hifei.com/#!firmware-upgrade/cdzo).

flraptor07
01-05-2015, 01:38 PM
Travis I had exactly the same problem, no WOT. I solved it with throttle travel

kfxguy
01-05-2015, 01:45 PM
Tab 5 of the Hifei software.

You can download the latest firmware from HiFei (http://www.hifei.com/#!firmware-upgrade/cdzo).

I'll check tonight, thx. I have heard it's hit or miss tho even with the update. I'll see how she runs this weekend. I'm in no hurry nor am I worried about it.

kfxguy
01-05-2015, 11:35 PM
I could not update it. For some reason, maybe I just don't know how to do it. The instructions aren't very clear.

I did figure a few things out tonight.

1) it does not like 0 timing, it stutters and sounds funny. Low timing is OK but auto seems the best.
2) it gets full throttle with the percentage set at 100 or 150...does not matter.
3) I kept reading the same logs or overlaps of the logs. I found that I need to get to the previous page and delete data log data if I wanted a fresh log. Also set the sample rate to 10 because with the default of 3 it took 30 seconds before it started recording. I kept getting an error message till I figured that out.

4) acceleration was set to standard. Just having the motor free spinning the acceleration of the motor was slow and took a few seconds for the rpm to top out. I changed the acceleration to hard and not it sounds and acts like a normal esc. I never tried this before because some other esc when set to hard are like a light switch. This one still retains the gradual low end like it should.

With the last thing being said I now know why it didn't go very fast. I was in a very small pond and the short bursts I gave it weren't long enough for the motor to accelerate to its top rpm. I should have better results next go round.