D3 Electric motor

[Chris PearceParticipant @chrispearce30862]

Hi all,

 I have a D3 engine in a sea commander 36" it gets very hot and cuts out, I have a 12 v speed controller and at the same time the batteries get hot, had a 9v 7.2 v and a 6 V lead batteries.

The prop shaft goes around lumpy, takes 5 goes to complete a revolution by hand

Any clues on the D3 engine?

ChrisP

[Paul TParticipant @pault84577]

Hi Chris

It sounds as though you have a problem with the prop shaft sticking..try striping the shaft down and checking the parts for rust / old grease then check the shaft and tube for straightness…re grease or oil the shaft (small amount) and reassemble the whole thing. If all is well this might just sort out the shaft problem and the overheating motor and batteries.

Paul

[ashley needhamParticipant @ashleyneedham69188]

Chris, were you the man at Bushy Park today??  I am the chap with box of bits and the battlecruiser…If so I think we may have sorted you out !

The boat was very tidy and well built, in plank on frame, nothing fancy, just a very nice workable craft.

For the benefit of the other (assuming it was you), our mans motor, battery and speed controller was getting very hot after just a few minutes, or less, running. The D3 motor looked a bit "hot " to me and we suspected that the motor was drawing too much current from the battery, overloading the ESC (current rating not known), and dropping performance after only a very short time. We tried a smaller (45 as opposed to the 50mm X as fitted) three bladed standard plastic prop from my spares box and the performance actually perked up a bit, the engine was heard to be revving much more freely, but still overheating. SLA gel batteries of course can`t put out as much current as NiMh ones, but when we put my 7.2v Ni battery in,. it also got really hot after less than a minutes full throttle! The "lumpy" progression of the prop shaft was actually the fearsome magnets in the motor stepping around. Our regime of action was to dump the D3 and try a , for instance. MFA 540/1 – as they are cheap- with a brass or plastic prop in the 30-40mm range, we thought a brass 35mm might be about right. This would provide a basis for further work, and a modest turn of speed coupled with a reasonable time-on-pond. Ashley

[Chris PearceParticipant @chrispearce30862]

Hi Ashley,

I thought I had seen your shot some where, yes It was me, small world.. I found out the motor is from a high performance car…! The former owner has said to go for a watercooled 550/600 how does that sound to you or fellow readers?

I have dug up a 12V 4 lead battery might see how that goes some when soon, probably fry the ESU.

The pond was terrible today, had to bath the boats when we got back,

so will arm myself with a brass prop and take it from there.

[ashley needhamParticipant @ashleyneedham69188]

Chris. Given that a new ESC is £20-£25, I think you should try to ascertain the current rating of yours first, then buy a motor to match it if you want something fast. Running 12v on your current set up will almost certainly fry the ESC in minutes, considering how hot it got after just one minutes running! I still think as an interim measure a trip to Maplins would be worthwhile for an ordinary 540, you will  have a yardstick for performance then, and a nice long endurance. I will bring my ammeter down next Sunday if you are there and we can have measure. Water cooling is great for high performance motors but I cant remember seeing this on your hull, you would need to get an inlet/outlet and drill and glue it in the hull for this.  Ashley

[Chris PearceParticipant @chrispearce30862]

Morning,

I had a look, there wasn’t any holes, as  for the 12v just a wild thought ! got a Ripmax 6-12V 20Amp Speed controller would that be able to handle the 12v for another project!?

 Will pop onto the maplins and get that engines and source props too.

I should be able to get there sunday morn

 ChrisP

[Penny LeeParticipant @pennylee76979]

Hi Chris,

I thought from the first few posts that there might be a grain of truth to the mis-aligned shaft business.

I now read a salient point from Ashley to which I strongly agree and I add my tuppence.

Ashley said…QUOTE    We tried a smaller (45 as opposed to the 50mm X as fitted) three bladed standard plastic prop from my spares box and the performance actually perked up a bit, the engine was heard to be revving much more freely, but still overheating.       End QUOTE

I say use a 540 or 550………choose your prop using rpm or current draw reading……..up volts 12 volt and water cool if needed. You will need an ESC with thermal cutout.

Lee Penny

[Chris PearceParticipant @chrispearce30862]

Hi Lee,

Any advice is good advice and well received, Ashley has some spare engines and we will take from there, I do like the idea of the water cooled engine, and after sunday may go down that route, the Sea commander does looks good at speed but not to fast, if that makes sense?

 Chris

[Chris PearceParticipant @chrispearce30862]

Hello all,

Update this D3 is a TM65-2 D3 Modified w/ tri-rotor arm blank. so what does that mean? looked on the trinity website, but no luck any ideas?

ChrisP

[60wattParticipant @60watt]

Guess:…….

I think a common motor has been taken it to bits, the number of turns halved by removing then rewinding copper wire in parallel and replaced the brushes.They possibly chrome plated part of it and stuck a fancy label and price tag too.

That would maybe make a 20 amp 3 volt motor from one that drew 10 amp at 6 volt  because the end user is stuck with a 7.2 pack

That means a motor is just run at increased power by changing its characteristic rather than increasing the voltage.

That is not a bad business model if you add re-labelling generic asian made products and advertising by sponsoring some "robot wars" types.

[Chris PearceParticipant @chrispearce30862]

Ok so far,

But what do you think it could be used for, ie in a boat, I will place it in the Sea Commander and see what it does with a 7.2V stick.

CP

[60wattParticipant @60watt]

Buggy racing

[ashley needhamParticipant @ashleyneedham69188]

As above, no boats.

[60wattParticipant @60watt]

Chris,although the modified motor says 7.2 ,the former owner might say it had a gearbox and was rated for two minutes.

I would fit your 550 or 600 and size the prop to give half the no load speed (for maximum thrust) when turning a prop in water.

If you ran a motor un-coupled on 7.2 and follow it by 14.4 with the prop in the water you could use nothing more than your eyeball to match the two speeds.

[Mike DavidsonParticipant @mikedavidson22772]

  Chris PearceTake your motor right out of the boat, then give it a coat of looking at    a minute spyglasss examination, making sure nothong is cought between the motor poles and the magnets, give it a blow through with compressed air/cleaning spray, then try the shaft without the motor  is there a bend in it ?is it free rotating ?was there end play in your shaft? it would help, lastly the prop is it free ?give it some end play stick it back together is it better? I bet it is . good luck, if that doesn’t work, get a bigger hammer

[Chris PearceParticipant @chrispearce30862]

[Author]

Posts