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I just picked up a 42" tunnel yesterday. I will post pics tomorrow. It has an older version Castle 2028 780kv motor and Swordfish 300A esc with the ali case.
Question. Is the motor better used on 8s or 10s for oval racing? It says 30k rpm max on the back. Also what is the best prop size range, the boat has an X457 with it.
Hello Peter,
I have run a 2028 Castle in a similar size cat on both 8S and 10S. Both work well. 8S will require gas size props in the 65mm range. 10S will run 50-60mm props depending on blade count and pitch. I found low lift Octura X series 3 blades work nicely on Aeromarine cats. Very smooth and efficient with minimal bad handling behaviors. I think my preferred prop was a X457/3. If you have both 8S and 10S batteries, try with 8S first and the 457 prop you have to get a baseline and measure temps. Then try 10S.
Here's some pics. Does anyone know what the hull is?
Attachment 170292Attachment 170293Attachment 170294
I found the usb link and cd for the esc too in the boat.
Thanks Tyler. I can do 8s or 10s, but will probably prefer 10s. I have an ABC 2414/4 chopper that I could run on 8s, and a few props for 10s. I could start with a X452/3 and move up to an X455/3 or X460, also Prather props up to P250. Will likely run only 10s 1P unless there is and advantage in using the extra battery weight for balance.Quote:
Originally Posted by RaceMechaniX
Peter,
That looks like an Aeromarine sprintcat. I run 2P in mine for weight and for running offshore classes which require a little more capacity depending on the the course layout.
10S1P will work just fine and as you said start with small props and work your way up.
-Tyler
Cool. Do you have/ can share any pics of your setup? This is currently set up with a center mount rudder. Does that work well or am I better going with an offset rudder for ovals? What about prop height? Asking because this is my first tunnel :unsure:Quote:
Originally Posted by RaceMechaniX
Hi peter a centre mount rudder or sturdder works perfect,irun a sprint cat 36(yours is a sprint cat 42/90)the advantage is it will turn on a dime some say it costs some speed ,but my saw record is 102mph so its ok
By the way this boat likes Prather props
Any idea what is the best CG?
Hi Peter i use CG at30% from boat length and you can play whit the CG by using the batterys depending on the wind and waves and the boat likes a chop.When setup is perfect it will be your best boat and you can not believe how this boat will handle
It is measured from the rear
Here is a view inside mine with the Castle 2028 and a MGM40063.
Attachment 170310
Tyler, what were your speeds with that setup?Quote:
Originally Posted by RaceMechaniX
I think it runs around 65-68 with this motor and a X457/3 prop. It was faster with a 2215 1.5Y and smaller prop but this combo is very safe and reliable. So I can use 20-25C batteries in a 2P set-up for offshore and finish comfortably.
I ran 72-74 I think with the Neu motor and Schulze controller on 10S.
Here is pic of that set-up. One with a 40.160 and the other with a 40.300.
Attachment 170311Attachment 170312
Video of it running with the Neu motor and a small prop.
https://youtu.be/E67v1hUxKA8
Got it all put back together this weekend. On powering up the motor it was noisy. In removing the end caps the shaft end bearing is shot. I have a couple of new ones so they will go in and I hope to be able to give it a run in a couple of weeks. Our club has 2-lap and 100m records that weekend, all done with laser timing gear. For club records we only run one way as our pond doesn't allow for much room to turn left and run from that end...for now!
Good times in Camarillo :thumbup1:
https://www.youtube.com/watch?v=AQCU2ljOIbQ
I miss Camarillo. That was a great pond hidden from the public.
So I got the boat out on the water on Saturday. It is fast. It's main problem is porpoising as it gets up to speed. It takes about 50 meters for it to settle but then runs flat and smooth. By porpoising I mean the bow really bounces.
CG is just forward of 30%. The strut is set fairly high, I have not altered it from where it was. I will have to measure it and take a pic tonight, but it is probably 16-18 mm above the ride pads (centre height).
So at this point, any suggestions as to how to get rid of the porpoise?
For the turns backing off the throttle a little and it corners well, as soon as you go wot it porpoises for half the straight before settling back down.
Do I try propping down and take off some speed to stabilise? I ran an X455/3 and P245, both props have been detongued a bit.
If I move the CG forward it may nose in and hook when cornering, it can do that now with a little too much rudder, dual rate is already at 30%.
Overall I am stoked with the boat having paid NZ$650 for it. Just need to dial it in a bit more. Any good suggestions to try would be great.
Hi Peter i have messured my prop seting it's 13mm centre propshaft above the ride pads.At what angle is the propshaft? is it positiv or level whit the ride pads, you can play whit this
Peter,
On my AM Conquest the prop is quite high in the tunnel, about 10mm above the bottom of the pads. Try shifting the weight forward to hit 33-35% COG. Or try adding a little negative strut angle.
The prop height is quite high, shaft center height is 17mm. The shaft is also pretty level. I am having trouble uploading pics again. I will try dropping the strut height a little and the adjust this one at a time.
Ok so I ran again on Saturday. Leaving the CG at 30% and bringing the strut down 3 mm resulted in a blow over. So I put the strut back up and moved the CG forward to 32%. This sorts the porpoising out quicker and it is much smaller hops. With an X455/3 it ran 94 kph, and with a P250 96 kph. I am sure it has more but I want to set it up to run ovals really, so I will continue playing around with the CG and strut height.
I also ran my DF 35 Pirate with a 6s set up and ran just under 98 kph on a ABC 1816, was happy with that.
Peter,
Try dropping the strut back down 3mm and put some negative angle in the strut. This will help push the nose down and reduce the chance of a blowover.
-Tyler
So I got in another run on Saturday. CG at 33% droppped the strut about 3mm and run a detogued P240. As expected it was a little slower, not much, but it was quite happy going around until a connector melted off. It was one that was done by whoever set the boat up so that is not a big problem to rectify. I had done 8+ laps. Getting it closer to where I want it.
So the boat got it's first club day racing on Sunday. Due to losing a cell on one of my 6s packs I had to change it to 8s. Ran on an X460 detongued and cupped and a P250. The water was rough and I won two heats and second in two heats, but I won the day on points. Not bad. The CG was at 34% even without the 6s packs and worked well in the rough water. I am enjoying this boat.