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I have revotronix 5s packs.
Are you advising to not run the 1750kv on 6s?
Are you advising to not run the 1750kv on 6s?
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IMPBA 20583 -
Not while working the hull out. That's 39,000 unloaded, probably 36,000 loaded up. It would be a good "hot" setup. If you got the 5s packs already, why not put them in parallel and get some good run time.
For comparison, I'm running 5300mah 2s packs, all in series. On my small motor, 4074 1050kv, the datalogger is showing 31,000rpm's. on the bigger motor, 4082 1200kv, I'm getting about 35,000rpm's. that range allows me to prop up without really picking up additional prop torque effects. I'll post more about prop torque in a bit, the boss is wanting something!Comment
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Oh yea, I definitely wouldn't run the 6s until I felt the 5s setup was running at its peak.IMPBA 20583Comment
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Bosses, always wanting you to do something...
IMPBA 20583Comment
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I'm not sure what level of understanding you have with prop torque. Let me explain, if you know this, then I mean no disrespect. Prop torque is a counter force, produced by the resistance of the water being cut by the prop. A CCW rotating prop, our rc standad, wants to pick up the left side of the boat. This in opposition to motor torque, which wants to pick up the right side of the boat. Motor torque really only shows itself when the motor is accelerating, while prop torque is constant. It's the reason we pay a closer attention to it. Now, have you seen a figure skater on tv, that comes in for a spin. They start with the arms out, away from their body. As they spin, they move their arms in, their spin velocity accelerates, up to the max speed with their hands close to their chest. This is a gyroscopic force. I mention it, because you have your batteries in line with the motor. So as the sponsons start to walk (and all hydros have some degree of sponson walk) that weight setup in your boat will promote a very fast side to side sponson walk. I purposely late d my batts out sideways, to distribute this weight out over each sponson. In effect, my boat is in the "hands extended" position. This uses the gyroscopic forces to slow the sponson walk.
Again, I don't want to direct you towards any particular solution Scott. The fun of the sport is learning. I have a long background in Hydro racing, from smaller class boats all the way up to Unlimiteds, with the Pringles boat and my brother, also Scott, was driving. I also had my "tiny boat", 36" nitro hydro boat running. The crew used to kid me about the tiny boat, but it ripped. Anyway, sponson walk is a very bad thing and can produce a violent crash on the water.
Again, one man's opinion, just food for thought!Comment
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Yeah, what's with bosses! Can't they understand I'd rather be running my tiny boat and if I can't run it, I'd rather be talking about it!Comment
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That was a great analogy to explain the torque and sponson walk! I think my 5s packs will be too tall to run horizontal of the keel. I wasn't setting this boat up to get but so fast, my idea was to use it to run with my daughters MG (faster of course), if I can get it to the low 50s with that 1750 motor I would be satisfied.
I have a new mean machine to build next, I bought a TP 4050 1570kv to run 5s in parallel, just looking for fun runs and maybe a 6s run here or there. When they are both up and running, I'll probably only keep one and concentrate on large scale gas again.IMPBA 20583Comment
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I just finished building a mean machine, interior space is pretty tight where the batteries go. Also you have very limited room to mount the strut and rudder. Also water check the hull before building as mine had a pretty good leak at the seams in the rear. Easy fix but would have been easier if I had checked prior to finishingComment
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Looking good!Comment
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Thanks,
as for the Popeye I heard the SSS 4074 2200kv 6 pole that OSE has was very good, I believe it was 785 that ran it and said he felt it performed better then the SSS 4082 2200kv. I have a carbon Fiber Popeye on order if it ever shows up.............Comment
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I really wanted the CF Popeye too! Not sure if they are ever going to be available... I had to settle on a fiberglass DF Vortex 34. It's a bit longer than the Popeye and I'm glad I went that direction. But the carbon boat looks like the nines!Comment
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Kind of feeling that way too. Was suppose to be in stock 3 weeks ago. I have a deposit on one, but if it doesn't show up in another week or so just going to cancel the order. I thought about the DF Vortex also but being a lazy sh*t I don't want to tape the hatch all the time and the CF Popeye has a nice inlaid boarder support all the way around the hatch for a latch kit.Comment
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I got my post wrong... the Popeye is slightly longer, but over 2" narrower that the vortex hydro. After looking at many posts before buying, I came to the conclusion that the width difference makes the Popeye less stable than the vortex. The Popeye is quite a bit lighter, but narrow and light means it will be limited to the degree of rough water it can take. So after considering this, I went with the vortex. I too, hate taping!!! So I came up with a solution. I'll post again with pics to let you see...Comment
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With this, I don't need to tape. The red rubber is from a silicone slab, about an 1/8" thick. It's fairly soft, 40 Shore. I got them from my wife's work. They make rubber parts and these are lab test slabs. I cut and used RTV to attach the strips to the fiberglass rails. I got the cinch screws from Aeromarine Laminates, they are 6-32 thread and they come with the blind nuts. They had O-rings to seal the screw to the deck. I didn't think that would be reliable, so I found some bonded washers that have much more effective area. It takes less than two minutes, and no taping.Comment
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Man, I'm glad you said something about taping! I just searched and found a silicone strip you can buy on the internet. It's 36" long, so no joints! And you can get with a pressure sensitive adhesive on one side. About $12 a strip. I'm going to get some, I don't trust the splices! Here's a link you can see: http://www.equalseal.com/product-p/redsilicone.htm
Here's where you get the bonded washers: fmw fasteners, p/n 2451001, $0.11 eachComment
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