sportygreg

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I recently got a vintage systems cat with the hydrospeed 606 that uses 2 speed 600 motors but the gears are shot.Anybody know where to get new gears or would I be better off converting to single 700 motor?Also,it has a mechanical speed control for 2 battery packs but I don't know if it is series or parallel? Thanks for any help.

Simon.O.

I am not familiar with the setup you have but I do have a lot of experience with gear drives in a few of my boats.
IF you can get replacement gears then obviously that would be easier.
Otherwise a conversion to a 700 8.4 bb would be the go.
I am about to put a new 700 bb in one of mine after the 9.6 let the majic smoke out.
Twin 600's can be run on up to 10 cells with good cooling otherwise 8 is about it.
The 700 I am lead to believe will happily spin on 10 and 12 lights it up well.
If you have a couple of pics of the boat especially the inside and drive unit maybe I and others here can help.
Gears can be found for kyosho and academy boats at some hobby shops, these may work out to.

Hope this helps.

Nina Roses Dad

I know someone who has a brand-new, spare gearbox for the 606 who might be willing to part with it. I'll let you know.

I doubt the packs are connected in parallel - the minute you connect 2 packs in parallel, the pack with the higher voltage will discharge into the weaker pack and one pack could have a weak cell and if the weak cell should short out, you'd have a runaway discharge of the good pack into the bad one, and the pack could overheat and melt the hull of your boat.

I think the motors in the 606 are rated at 7.2V, so my guess is that they're wired in series (meaning that they run together at 14.4v) and that the controller connects both packs (6 or 7 cell) in series for full speed and just connects one pack for the slower speed. You would still have a separate pair of wires running from the speed control to each battery connector.

Unless of course, you see a big power resistor inside the hull which was another implememtation of a 2-speed electromechanical speed control - for "slow" speed it would switch the resistor in series with the motor to drop the voltage to the motor (generating a lot of waste heat in the process). Either of these setups is junk. So, you'd want an ESC that can handle the voltage of 14 cells or 4S LiPo, say 20 volts maximum. 40-50 amps rating would probably do.

Twice the volts at half the amps, the watts are the same, and less is wasted as heat.

sportygreg

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Thanks for the replies-I am getting rid of the Graupner so don't need gears anymore.It seems the older gears with the brass inserts and gray plastic all fall apart due to the different expansion rates.The brass gets hot and expands thus cracking the plastic gears-I notice that some newer Graupner gearboxes now have white nylon gears which are more flexible than the brittle gray plastic they used before.I had the same problem with an Electro Vee but converted to direct drive with a 700 motor.