Need help with my HPR setup

[TheShaddix]

I can definitely live with that. Thing is though, my blackjack 29 is also a pretty quick boat but it behaves perfectly well at slow speeds and the design is similar, just 16 inches shorter. There seems to be more to it than just the HPR not being made for slow speeds. Also, do you put loctite on any of the nuts and bolts that are on the prop shaft and the nut that holds the prop itself ?

[nata2run]

The HPR is very narrow, and at slow speeds it "wobbles" causing the sponson to dig in the water making it turn to one side, then you counter turn and the opposite happens, until you pull the trigger and get it out of the water. If on a standstill, and you pull the trigger, it will not track off the slightest! It was designed for optimal speeds "almost at any cost" and yes they go well! If there is a bolt to prevent the prop shaft from gliding out, you can use threadlock, you should where possible use a locknut that won't shake loose.

[TheShaddix]

Now that makes sense! It does look like it just cuts the water with the sharp, long sponsons. I'll look into replacing the two prop nuts with the locking ones. How do those look, by the way? They just have some plastic built into them? Also, do you know of any ways to make the hatch be 100% sealed? I use tape but a bit of water sometimes still manages to get in. Is there some kind of a thin foam tape to lay into the groove around the hatch? And what's the best hatch locking solution? I tried using 4 bolts on the corners but that didn't really work out. The nuts on the boat side would just snap loose eventually, the epoxy would not hold them well enough. Looking for something that is quick, clean, and tight, and preferably centers the hatch into the groove so all 4 sides are equally spaced.

[nata2run]

Luck nuts have a nylon washers embedded into the nut, if you ask for one I'm sure that's what you will get. But make sure everything you use is stainless. regarding your hatch, you can have it 100% sealed and still find water in the hull. Every screw hole where mounts or drives are attached is a potential leak. (even your antenna plug) you should have a sponge or some crunched up paper under the stuffing tubes to pickup water that may sneak in (you have wire drive so you may look into some other way) The tape is more or less your water protection, but a "safe hatch" should be screwed to the hull. If you have a bad crash at only 60mph with tape holding it down only you run the risk of ripping it off and sinking the boat.

[ManuelW]

If set-up properly a HPR06 will go nice around corners, also at slow speeds. Just a question of right props, CG and trimm setup. You can play with it to find a suitable combination. My own 06 goes over 100mph with the right props, still perfect handling at slow speeds and quite good cornering. Okay it wont go round the course like a MHZ Mystic which seems to be glued to the surface and running on railroad tracks but looks really nice and scale, no odd behaviour.

Few videos what is possible:

http://www.youtube.com/watch?v=kl-xRfcobbc

http://www.youtube.com/watch?v=P64s8aKVsZg

http://www.youtube.com/watch?v=JX5qOhN7t1k

regards,
Manuel

[TheShaddix]

To be more specific, my boat turns really well at slow speed. The issue I was mentioning was that it seems to have a lot of momentum/inertia when turning. So let's say it's going straight at slow speed, then when I turn it it turns right away and is great, but it doesn't straighten out right away like it should. Maybe it is the center of gravity because I notice it at high speeds. The other day I was running it, around 70-80 mph it jumped up on a small wake and just took a huge dive, disappeared for about 3 seconds under water. The only time that should happen is if the cog is biased towards the nose because it should have just hopped instead of going nose in. Stefan said that at speed it should have just the rear touching water, but my boat touches the whole underside. I'm running 6s 6000 turnigy lipos, they are really heavy. I'm guessing his original battery placement was well forward because he was running 5s 5000 which are way lighter. I'll just play with the setup and see if I can find the perfect medium.

[RaceMechaniX]

Shaddix,

If you are in SoCal if would be worth a trip this weekend to Legg Lake where we are hosting a straight-line speed event. I know several very fast HPR's will be there and it's always helpful to see other's set-ups in person.

TG

[TheShaddix]

I'll be there. What day, saturday or sunday? And what time is it ?

[TheShaddix]

Does anyone know what kind of expandable foam I can use to fill up the bow of my boat? I saw one of the guys at the lake event today had all of his HPR boats (5 or so of them) filled up with foam in the entire bow area which made them very rigid and didn't add much weight, and his boats are the fastest I know of, some hitting 140 mph. He didn't remember the name of the foam he used though. My boat is very flimsy when you press on top of the bow since it's just a regular CF hull, so it would be great to have a solid feel to it. And I also want to get rid of the pool noodles in it because they aren't attached and are just floating freely in there.

[ManuelW]

That must have been Brian out there at the lake, he doesn't only have foam in there but also in combination with two thin CF bulkheads on left/right side. Foaming was done very properly, good craftmanship.

regards,
Manuel

[larryrose11]

Others have used pollyeurathane foam. It is a pour in place, closed cell. 2lbdensity is rigid, but 4 lb density is structural.

http://www.aeromarineproducts.com/boat-foam.htm?gclid=CPap1Pvrm7wCFU9p7AodWzEATg

a cheaper option: this makes 2 cubic feet
http://www.amazon.com/Urethane-Inclu...hane+Pour+Foam

this makes 1 cubic foot,
http://www.amazon.com/Urethane-Inclu...hane+Pour+Foam

[TheShaddix]

That must have been Brian out there at the lake, he doesn't only have foam in there but also in combination with two thin CF bulkheads on left/right side. Foaming was done very properly, good craftmanship.

regards,
Manuel

I don't remember his name, but his boats are all Tommy Bahama, and they are amazing. I also liked all the custom hardware he made for them.

Others have used pollyeurathane foam. It is a pour in place, closed cell. 2lbdensity is rigid, but 4 lb density is structural.

http://www.aeromarineproducts.com/boat-foam.htm?gclid=CPap1Pvrm7wCFU9p7AodWzEATg

a cheaper option: this makes 2 cubic feet
http://www.amazon.com/Urethane-Inclu...hane+Pour+Foam

this makes 1 cubic foot,
http://www.amazon.com/Urethane-Inclu...hane+Pour+Foam

Thanks man, I think I've tried the first option (aeromarine) on my blackjack boat and I noticed it's very hard to get the foam even and perfect. It just kind of goes anywhere it feels like and if I mess up, that's it. Any suggestions as to how to pour it, etc?

[larryrose11]

use a funnel and a straw. clean up your funnel immediately after words with acetone.. Put it in in a few pours. small batches of the stuff works best.

[TheShaddix]

Thanks for the info. Foam ordered. Another issue i have is trying to find the bolts/nuts for the hatch and boat. I have some m6 stainless countersunk bolts, I just need those t nuts that go on the underside of the boat hatch surface and are secured with 2 other smaller bolts on either side. I've looked everywhere, local and online, can you guys tell me where you get yours?

[bracka69]

Here is some links to Hatch Bolt kits. http://keithbradleyboats.com/product...olt-kit-black/ or http://keithbradleyboats.com/product...kit-stainless/