DF Sniper 45" CC 2028 8s2p

[riptide1]

video of today's run!!

Today I ran at a nice neighborhood pond with ose member mdunham. I worked out the overheating issue by adjusting the stinger angle to neutral with the bottom of the boat, keeping the teflon as a test, and more importantly using a thrust bearing with grooved washers. I ran two different ways 1st with maybe 1/64" spacing between the thrust bearing and stinger ..just enough room to spin the bearing freely. This resulted in the flex shaft running the coolest right at 100 degrees, measured after the run on shore; but all the electronics were about 25% hotter, even the lipos came back warm and I lost about 20% of runtime. The run in the video linked here, was best with a 1/16" gap and the thrust washer still engaging under heavy load. I under-estimated the speed, mdunham's gps read 51mph consistently.

http://www.youtube.com/watch?v=E0dknx_clrk

[m4a1usr]

Looks better! It might just be the speed your running at but the hull looks like its running wet to me. Not terribly. Have you played with moving the COB back a tad? Also are you saying your running with a 1/16" gap between the drive dog and the stinger with a thrust washer in between? I must have missed it in a previous post.

John

[riptide1]

No the thrust bearing itself is wider than 1/16" ...I was trying to be detailed in saying that running both a small gap and thrust bearing fixed the overheating issue. The COG is at 30% or 13.5" from the transom. I have thought of moving it back more, but because of the way I have mounted the esc on top of the batteries in front of the motor, there is nothing I can easily slide backwards. I just received an x460/3 prop and want to wait and try it before redoing my esc mount and moving the batteries out of the center.

Looks better! It might just be the speed your running at but the hull looks like its running wet to me. Not terribly. Have you played with moving the COB back a tad? Also are you saying your running with a 1/16" gap between the drive dog and the stinger with a thrust washer in between? I must have missed it in a previous post.

John

[Punisher 67]

Looks better! It might just be the speed your running at but the hull looks like its running wet to me. Not terribly. Have you played with moving the COB back a tad? Also are you saying your running with a 1/16" gap between the drive dog and the stinger with a thrust washer in between? I must have missed it in a previous post.

John

Actually John I run my COG at about 31.5% on my Sniper but I am a few pounds heavier than Josh also , I noticed the front constantly porpoising . Try 29% like John suggested to see if anything changes then try 31% like I have mine setup and also see what changes

Nice run Josh 60mph is definaitly within reach , My favorite prop on mine is the X460/3 and for longer run times I run the X455/3

[Diesel6401]

Nice Rip... Glad you and Mark where able to get together. Sounds like you guys had some fun today. Sorry couldn't join the festivities today. Hopefully sometime soon we can all get together....

[riptide1]

I did some work on the boat today and am going to get out and run her in the morning ...I installed a capacitor cooler over the two caps on the Etti not in the bank ...these were the hottest. I am going to be running a larger prop without the edges rounded down (the x460/3 pictured on right) and am curious to know what you guys think the resulting change will be. I'm hoping for a bit of lift and more top speed ...

[rearwheelin]

Cool cap coolers !....Definatley a good insurance policy to help delay heat build up. Another thing to consider are your bullet conecters.. Make sure you conecters are rated higher than what your motor will draw, make certain your C rating is getting to the motor in other words, if your c rating doesn't make it to the esc then your motor will suck the life out of your caps ! Good luck with the run !

[riptide1]

I know the connectors look like plastic junk but there are gold 6mm bullets under the shell ..HK says they are good up to 250A ...and while my wire is long it is 8awg. I'm hoping the prop will make the boat run less wet ...the drive side is running with little resistance now ...the tabs are up ...the next thing would be to move the CG back to under 30%

Cool cap coolers !....Definatley a good insurance policy to help delay heat build up. Another thing to consider are your bullet conecters.. Make sure you conecters are rated higher than what your motor will draw, make certain your C rating is getting to the motor in other words, if your c rating doesn't make it to the esc then your motor will suck the life out of your caps ! Good luck with the run !

[rearwheelin]

I know the connectors look like plastic junk but there are gold 6mm bullets under the shell ..HK says they are good up to 250A ...and while my wire is long it is 8awg. I'm hoping the prop will make the boat run less wet ...the drive side is running with little resistance now ...the tabs are up ...the next thing would be to move the CG back to under 30%

I know your solders are good

[riptide1]

I know your solders are good

Yeah thanks to your advice on using a little propane and silver solder

[riptide1]

I just ran with the x460/3 prop and it is perfect. I gained 5mph, heat was the same, except for the new cap cooler, and run time was the same. The boat runs higher out of the water. I'll have to try pre-cooling the system with ice water in my garden sprayer and preheat my lipos some how. Other than that, I'd say this boat is dialed in ....55mph on 8s with 8min run time. New video coming after next run.

[Old Sloppy]

go to 9s & x457/3 if you think the amp draw will be acceptable.

Harry