1/6 scale Jetsprint boats and 30mm Jet drives

[mickieb49]

Yes you are right about these are designed to run in shallow water, as such they are designed to ride high when they are under power, the problem I have is that there is maybe a little too much power for this hull, all the same, this is not a bad problem....
The trick is to make them run well in all conditions....
I should be starting the plug for the marathon hull very soon, so I will have to go thru all the set ups again ...
Have you got your jet unit yet Mike?
Regards Mick

[gsbuickman]

Hiya Mickie, I wanted to drop you a line because I thought you may be interested in a possible collaboration deal with this dude.
http://forums.offshoreelectrics.com/...-4-scale-hulls

He's thinking of the jet pump from Hobby King for his 1/4 scale aluminum boats, I thought you may be able to offer him a more viable solution. This is the pump he's thinking about .

http://www.hobbyking.com/hobbyking/s...e_X_Large.html
I can get his contact info for you if you like.

Cheers
Jim .....

[mickieb49]

Thanks Jim, i may drop him an email.

[Mike Caruso]

Yes you are right about these are designed to run in shallow water, as such they are designed to ride high when they are under power, the problem I have is that there is maybe a little too much power for this hull, all the same, this is not a bad problem....
The trick is to make them run well in all conditions....
I should be starting the plug for the marathon hull very soon, so I will have to go thru all the set ups again ...
Have you got your jet unit yet Mike?
Regards Mick

Pump got here today very nice now the work starts.

[Mike Caruso]

Hey Mick,
I have a couple of question #1 the pump made from what type of black plastic is there some type of glue that will stick to it? #2 when pump is mounted to floor of hull the Impeller is at downward angle appox 3.5° why? #3 pump housing flange that mounts to the hull could it be made wider? Only need extra width on the flange for mounting screws as no room for error.
TIA
Mike

[mickieb49]

Hi Mike,
The plastic is ABS, if you want to stick something to it, I suggest you give the surface a rough up with sandpaper first then use some epoxy glue.
The impeller needs to have a downward angle to help keep the nose on the water, if it was flat, you will need to have a lot of trim pointing down.
I couldn't make the flange around the too much bigger as then it wouldn't fit on the bottom of the hull, I suggest you start with a smaller drill than necessary, then work your way up, this way you should be able to get the holes in the centre of the bottom flange.
It is a little bit too late to change the flange width as that Is a very costly change to the injection molds.
The new plug has been machined out yesterday, I am hoping to be starting the mold next weekend, then laying the hulls up very soon after.
Regards Mick

[mudboggin3]

What would a complete kit run and when can I get one.

[mickieb49]

What would a complete kit run and when can I get one.

A kit will be $275 AUD plus shipping, you will need to get your own electrics, servo and motor mounts. Mold is done on the new bottoms, I am hoping to get some time and polish up the mold, then lay up a hull next weekend, hopefully run it the week after, providing all goes well then I will start mass production of the hulls. Please be patient as I am a 1 man band, and between working full time, looking after 2 toddlers I do not get the 20+ hours in the shed I need to get everything done..
I have a few kits of the first version ready, they are on ebay at the moment, or you can wait.
Regards Mick

[Darin Jordan]

Mick,

Quick couple of questions... well... actually one request for confirmation and a question...

1) Am I seeing correctly that this jet pump unit has adjustable trim angle as well as nozzle steering?

2) What power range is this unit designed for? P-Ltd style system? What RPM's are recommended, or can it handle?

Thanks,

[mickieb49]

Mick,

Quick couple of questions... well... actually one request for confirmation and a question...

1) Am I seeing correctly that this jet pump unit has adjustable trim angle as well as nozzle steering?

2) What power range is this unit designed for? P-Ltd style system? What RPM's are recommended, or can it handle?

Thanks,

Hi Darin,
You would be correct, it has both steering and trim.
The Max rpm I have tested it to was 28000 rpm, I wouldn't suggest you go over that anyway, as it will start to work against itself by making too much back pressure.

On another note, the first of the new hulls is layed up, I should be pulling it out of the mold tomorrow, then give it a run next week sometime.
Cheers mick

[timjz]

Very nice work!

Quick question, would a true flat bottom (Dumas SK Daddle) hull still need a center skeg with a jet drive?

Also, would the 27" Dumas SK Daddle be better suited to this drive, or the 36"?

Edit: nevermind, just ordered the 27" kit & a jet pump!

[mickieb49]

Hi Tim,
The problem with flat bottoms is the side slippage causing turbulence into the unit on turns, will work just not optimum.

On a side note I have been busy with the new mold, I will upload some pics a little later on , basically the mold is done and I am progress in getting the hulls built as quickly as it will allow.
I have been researching into getting the hulls manufactured in ABS, and it looks like I will be able to provide these hulls at a cheaper rate, so basically initial prices may look more like $200 for a kit.
The marathon hulls are also getting closer, as is the decal kits.
Please let me know what everyone thinks.

[mickieb49]

hi guys,
Just a quick update, just started putting together the first hull with the new bottom ( see pic) also got the hull working much better now, set the COG at 260mm from the transom, and if you do the maths, that is 40%, the reason being is that this unit is slightly too much for the small hull.
Also look at the internal setup , instead of cutting the shaft shorter on the unit, iam going to keep it at 150mm so I only have to put the battery infront of the motor to get the right COG.
Take care20140316_132454.jpginside .jpgnew bottom.jpg

[Mike Caruso]

Hey Mick,

I just finished my hull bottom.

I started with a blemish hull and have learned a lot about how to work with filler.

0.1 Hull strikes filled 2nd.JPG1.2a Transom clamps 1.jpg1.0 strikes sanded off.JPG1.3a carbon floor cover.jpg

Mike

[flraptor07]

Mick, I don't know about anybody else but I would rather pay the extra $ for a Fiberglass hull over ABS any day. Fiberglass is much easier to repair and much stronger, in my opinion I wouldn't bother making a ABS hull. I'd like to hear what any body else thinks about this. When I'm looking at a hull and I see it's ABS I quit looking, I won't even consider buying a ABS hull.