Carbon shocker build

[kfxguy]

I'm

kfxguy: What do you use to outline/imprint your parts (like rudder, strut mount, etc) onto the hull before drilling? I'm trying to find some sort of sticky thin foam to make an imprint of parts on hull before drilling but was wondering if you use anything different.

Dremel for large stuffing tube holes, or regular drill bits?

Have you ever considered using spring steel (2.5mm - 3mm) to use instead of flex cables? Thinking about using them for a cat... but I'm unable to find a good supplier of them, along with 3/16 stubs to use with them.

Tape up area. Position. Mark holes with sharpie. Drill pilot hole. Then drill to size. Only one hole. Drill bit can walk. So I then keep checking by putting a screw in the hardware and go from there. I've also double stick taped hardware to hull and drilled the holes.

I prefer flexes. It's what I know. I'm starting to make my own. My bends are to much for wire anyway.

Stuffing hole. Mask off. Position motor. I have a .187 stub goes in collet. To help mark location. I have a large digital caliper to make sure the hole is in the centerline. I drill the hole within .002 of true center. Drill pilot hole. Remember the masking tape...incase you slip too. Then I have a tapered bit that is marked, I drill to the mark. Two holes. Connect the holes with a Dremel cutoff wheel. Then a small sanding roll on the dremel to finish it off. If it's not perfect don't worry epoxy will cover it. Then I have another .187 rod that goes in collet. Couple piece of brass sleeve that sides over to center everything.

[kfxguy]

Im assuming Travis has a lathe and a tool to cut the groove in the strut for the snap ring

Correct. Don't bother with a drill or drill press unless you have a fixture to make it perfectly straight. I made the snap ring groove tool. Took about an hour to grind a hss blank into shape lol. R156 bearings.

[kfxguy]

Just noticed this one: http://i218.photobucket.com/albums/c...CC1103B81F.jpg

Love the color combo... looks sick.

kfxguy: Btw, are these speedmaster struts? http://s339.photobucket.com/user/tof...pn5do.jpg.html

That's exactly how I'm painting this one except I'm leaving the fightercat head out. That will be a carbon decal. Much easier to do that way.

[kfxguy]

I see your trying a tapered rudder Travis. Just cause?

Well I'm not sure the effects it will cause me. In the pic on speedmasters website it didn't look as tapered. He's making some straight rudder for me anyway. I needed something longer and that's all I could font that fit. We shall see.

[srislash]

Well I'm not sure the effects it will cause me. In the pic on speedmasters website it didn't look as tapered. He's making some straight rudder for me anyway. I needed something longer and that's all I could font that fit. We shall see.

I have both for my 'BlownAway'. I'll be testing the difference as soon as I am used to it. Just figure it falls under the 'good to know' class.
I was just curious if you were doing the same.

[kfxguy]

I have both for my 'BlownAway'. I'll be testing the difference as soon as I am used to it. Just figure it falls under the 'good to know' class.
I was just curious if you were doing the same.

Let me know what you find. My comparison won't be fair as the rudder I had on it is about right for my Rivercat but not this boat.

[kfxguy]

Srislash, I ran the shocker today with that tapered rudder. It was much more stable although it was 10mph slower (much less kv motor swap remember). It stuck to the water. I had to keep giving some positive to the prop to go faster. I shortened it a little before running it but I'm about to take another 1/4" off and see. I made lots of passes and went through two sets of packs. It only went 74.1 on 7s so far but I found some issues that need correcting. The prop was so deep that it was going into a false lvc from time to time if I made a long pass. I'm not sure why but I lowered the lvc to 3.0v (I'll never run it to that because I check the voltage between passes). I pulled a log from it and my average amps under load is around 170-180 with a max (couldn't find the max point in the log though) of 219.1 amps. So I'm plenty safe at this point in going up on prop and voltage. I do like the fact that I can drive it around on 6s and 7s. Getting back to the rudder, I think it's a bit too long as it was bouncing at first. I think the prop is almost neutral right now, I didn't realize how much negative I had in it before in a effort to keep it on the water. I've got some new props coming that aren't even out yet for me to try. This one I have is a Dasboata that my buddy gave me and it's not sharp and the leading edge is pretty thick...had some decent prop walk at low speeds so I know I can sharpen it and get more out of it. It's a process as you know. But I guess I'll take 74mph as not too bad on tuning it in. I never gps my original shocker but this one looks faster already and I was happy with it....but now I'm chasing a number on a gps..... Lol

[srislash]

74 is respectable start Travis. You'll give her the ol' 'nip n tuck' and get her dialed. So my biggest concern with these hulls, how does it handle?
Mine sucked at first but I had one of the first ones and notice the runners different on my new one. Slightly tapered this time.

[kfxguy]

74 is respectable start Travis. You'll give her the ol' 'nip n tuck' and get her dialed. So my biggest concern with these hulls, how does it handle?
Mine sucked at first but I had one of the first ones and notice the runners different on my new one. Slightly tapered this time.

It's not too bad once I figured all all the wrong stuff I had with it. I text mr Jim at abc props after I posted that last post and he had me send him the data log. He picked out something in it I didn't notice. It was surging. It did have a bounce to it and the rooster tail was not constant...it was erratic. He told me go check my strut angle and said it's too much negative. He was right. (I kept giving it positive but not knowing my last adjustment was still in the negative) I took a pic and sent to him. The he called me and we talked for over two hours. I think ive got it lined out now to go faster tomorrow. The motor is an issue though. It's supposed to be 1580-1600kv but it checks in at 1460-1480kv. I should be in the 70's on 6s and not at 62 on 6s. It should pick up to about 67 on 6s tomorrow with the changes I've made but I'm unsure. Not sure what I'm going to do with this motor now. I really didn't want to run it on 9s.


You've got to look real close and you can see how much it was still pointing down

[kfxguy]

74 is respectable start Travis. You'll give her the ol' 'nip n tuck' and get her dialed. So my biggest concern with these hulls, how does it handle?
Mine sucked at first but I had one of the first ones and notice the runners different on my new one. Slightly tapered this time.

What are you referring to? The sponsons? Yes these angle up toward the front. All my other boats sit flat. See if you can tell in this pic






Also this longer rudder is what I ran today vs the shorter one shown. It didn't handle too bad but it had to prop walk due to a dull prop. I did shorten the rudder after this pic some

[zooma]

I noticed that your rudder bottoms are tapered more toward the trailing edge. Do you do that or do they come that way? I just round the bottom, but not taper it. What is the best for handling?

[kfxguy]

I went run it again today. Ran much smoother and faster on 6s. Then went slower on 7s. Made some adjustments and seemed to pick up but batts were run down at that point. Tried 8s but it crashed. Not sure why. It didn't blow over. Just rocked one way a tad and went to flipping. Here's The flip

[kfxguy]

Here's a 7s run

[kfxguy]

So I have some thoughts. This crash has been bothering me. I played it back in slow motion many times. It almost seems as it it hit something on the right side and the left side dug in. I dunno. There's no damage. The boat was driving so well and it was stable and turned well. The only other thing I can think of is the carbon extension I made (which was temporary) became flexible. The other piece of carbon was detached when I get the boat in. Could have happened and caused the crash or could have happened because of the crash. I did notice more of a gap between the two pieces but I didn't try to flex it. Teach me a lesson there.... The epoxy didn't let go though....it peeled layers of carbon. I dunno, this has to be the issue. No damage to the hull. I've never had a flip like this.


My next issue. The motor was supposed to be a higher kv. My checker which has been extremely accurate, says its 1450kv. My loaded rpm is only 32k on 7s and on 8s it's not gonna be where I want it. 9s is what it's gonna take but I don't like having to run that much voltage. At that point I feel like I'm just throwing voltage at it. I will say this, looking closely at my logs last night, it's pulling an average of 160-170 amps at full throttle so nothing is breaking a sweat at this point. I predict that 9s won't be that bad either. Should I just accept the fact it's not a 8s setup like I wanted and just move forward how it is or should I call neu and tell them I got the wrong kv, again? I bought a 1440kv tp 4070 to kind of tone it down later on so that was a waste. I'm not sure what I should do at this point.

[srislash]

These things change as we go Travis, just goes like that. I would think the weight/balance would be the bigger issue so adding cells may hurt you.

I would say the flip was the CF separating if no other anomalies were present. Odd though