Experiences with Graupner Jet Drives

[ThunderboltV12]

Well, I have had my Graupner Atlantic Challenger for about 6 months now, and it is definitely one of the coolest boats I have ever owned, and I love the jet drive system, even though most people seem intent on eliminating it in some way or another.

For a boat of its size (over 4 feet long), it maneuvers surprisingly well thanks to the jet drives, and it's got a lot of speed for the motors and voltage that it runs. I have other boats of similar size using Z-drives and direct drives with rudders, and it just is not the same at all. One of my greatest concerns with the jet drives was debris. I figured that these things would suck up anything in sight, and it would clog the drives.

Couldn't be further from the truth. I took my boat to the lake today, and unfortunately, it is a stillwater lake and has a lot of stuff that grows in the lake and kind of migrates around it.This stuff manages to clog up the Octura props on my Villain IV, but the jet drives just ate it, chopped it up, and spit it out, or simply passed it along its grates without ever having ingested it at all. At the end of the day, I found very little plant matter stuck in the drives.

These drives are equipped with the reversing buckets as well. I am quite fond of this feature as I simply run a very powerful forward-only ESC, and when I convert to brushless/lipos, I won't have to worry about the expense of a powerful ESC in order to maintain reversing either.

The lack of exposed props gives excellent maneuvering in very shallow water, and extra safety when handling the boat while it is still powered up.

Overall, I am very satisfied user. I must admit that I love the novelty of the whole thing too. It's a lot different than my prop boats, and very cool. :cool:

[BIGSails_0830]

I have to agree with you on the pros of a jet drive system. Here in Davenport, Iowa, we have a rocky island in the middle of our pond and nearly everyone in the local boat club has gotten hung up on the island by their props and rudders. I wanted something with a smooth hull, no exposed hardware below the hull line, that could go in and get those stuck boats. On my 30" PBR I have 2-28mm KMB drives powered by Johnson 700BB motors. Though the boat is not finished I have run the hull through and over "junk" that wouuld have fouled other boats. The only problem I've had has been with scale logs. Luckily the bend inside the drive prevented the sticks from reaching the impellor. To prevent any future damage, I've installed the "log" guards over the intakes.

On the mechanical side, the onnly trouble I've had is the control wire for the reversing plates. they are epoxied into ball joints. Under the high water prssure, the ball joint seperates from the control wire and the reverse plate is deployed, causing the boat to turn in circles (one drive forward, one drive in reverse).

Since this afternoon is suppose to be crappy and I won't be able to mow the yard :(. :D I'll try and post pics this evening.

Matt

[ThunderboltV12]

Yeah, I need to get some pics up too.

My reversers use the same type of connection that I use for my turning. The joint is threaded internally, and the metal rod goes right in. No problems yet.

I had considered the same problem with sticks getting in, so I grouped my slats close enough that anything small enough to get between the slats will be obliterated by the impellers. ;) I had thought I might lose a little speed with the closer grouping, but no complaints so far.

[ernest2]

i agree! all my electric boats have jet drives (mini-jet from graupner.). what i really like about them is the simplicity of the setup, its like plug n play, lol..

[warren hulbert]

Earn:

I need some help as I am building a sk Daddle from Dumas and I would like to use a Konkronik 600-17 brushless motor and a 80 esc with two seven cell packs that are 4500ma. Will the 40mm Graupner jet drive handle 29,00o rpm's or should I use another prop drive in the back. Any help would be much appreciated. Warren in the Desert

QUOTE=ernest2]i agree! all my electric boats have jet drives (mini-jet from graupner.). what i really like about them is the simplicity of the setup, its like plug n play, lol..[/QUOTE]

[warren hulbert]

I was thinking that a hot cake turner sanded to fit would work to keep junk out what did you use? War

Well, I have had my Graupner Atlantic Challenger for about 6 months now, and it is definitely one of the coolest boats I have ever owned, and I love the jet drive system, even though most people seem intent on eliminating it in some way or another.

For a boat of its size (over 4 feet long), it maneuvers surprisingly well thanks to the jet drives, and it's got a lot of speed for the motors and voltage that it runs. I have other boats of similar size using Z-drives and direct drives with rudders, and it just is not the same at all. One of my greatest concerns with the jet drives was debris. I figured that these things would suck up anything in sight, and it would clog the drives.

Couldn't be further from the truth. I took my boat to the lake today, and unfortunately, it is a stillwater lake and has a lot of stuff that grows in the lake and kind of migrates around it.This stuff manages to clog up the Octura props on my Villain IV, but the jet drives just ate it, chopped it up, and spit it out, or simply passed it along its grates without ever having ingested it at all. At the end of the day, I found very little plant matter stuck in the drives.

These drives are equipped with the reversing buckets as well. I am quite fond of this feature as I simply run a very powerful forward-only ESC, and when I convert to brushless/lipos, I won't have to worry about the expense of a powerful ESC in order to maintain reversing either.

The lack of exposed props gives excellent maneuvering in very shallow water, and extra safety when handling the boat while it is still powered up.

Overall, I am very satisfied user. I must admit that I love the novelty of the whole thing too. It's a lot different than my prop boats, and very cool. :cool: