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Author Topic: options for a 90 degree shift of final shaft..  (Read 5448 times)

rathikrishna

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options for a 90 degree shift of final shaft..
« on: August 05, 2010, 02:22:18 pm »

HELLO...i was using props to all my models, all made out of aluminium sheets..i always uses toy gear boxes for final drive, so the RPM will be lesser.even though the TOURQUE will be suffish.but i am facing a problem of MOTOR BLOWN OUT...after running for a little while, my motor burns out ..why this happening..?...can anybody clear this out..?..i always use 6 volts, 5 amps battery with my models..why this happening to me..?. and what type of prop can be used in a low RPM final shaft..? please help me once...
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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #1 on: August 05, 2010, 03:25:36 pm »

sound to me like to much friction in the shaft (metal on metal contact) causing the shaft to become hot & hard to turn leaving the motor struggling to turn it and eventually 'blowing out' or burning out...

suggestion use a brass prop and grease it well before and after a run also check the coupling to make sure it turn freely .. you should be able to spin the prop with your finger so it moves a turn or two easily before it stops 

also check that the prop is not bent ... that will incur more friction and more force being applied to the motor, also check all gear meshing or belt tension to tight on any of these will not help the motor turn freely to loose and well nothings going to work anyway..

also check the motors max voltage or amp's it can handle and be sure your esc is able to support the motor.
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #2 on: August 06, 2010, 07:07:26 am »

Sir...thanks for the advice...the whole shaft is free and runs on the bearings nicely...there is no jamming.i will show you some motors with me....if i run my model for a long period it will wurns off..i dont know what to do....
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Umi_Ryuzuki

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Re: options for a 90 degree shift of final shaft..
« Reply #3 on: August 06, 2010, 07:20:52 am »

Perhaps a smaller propeller or less pitch, will decrease the load on the motor.

If you want to continue to use the propeller, then a larger motor may be necessary, or one
that doesn't draw as many amps under the same load. If the motor has a high rpm, then you
might consider gearing the  motor down 2 or 3:1 to the propeller.

 :-)
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #4 on: August 06, 2010, 07:48:42 am »

thank you sir....i have many motors with me....EP 400, Rs 380, 580...but when i use these the battery runs out instantly....how can i overcome this prob ..please...once...
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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #5 on: August 06, 2010, 08:44:23 am »

normal running time on the batterys is only a few mins im asuming your running on nicads or lipos?
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #6 on: August 06, 2010, 02:49:13 pm »

yes i have...Ni cds..Lipo s,Ni Mh..but i dont know how to extend time...i have some engines, runs on ETHER, and nitrous oxide,used to make aircraft models...but its too powerfull on boats...so now i have purchased a chain saw, from MAKITA, and dismantelled all things from it, except its 35 cc two stroke engine.i am in my work room to make a good racer with that engine...but still i am sad that i have to extend the timing of my DC motorised models...because i love them, as all it works silently...
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Tug-Kenny RIP

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Re: options for a 90 degree shift of final shaft..
« Reply #7 on: August 06, 2010, 02:53:17 pm »


I see you have a Multimeter.  You could test the 'amps' drawn by the motor and see how long it runs before going flat.   

Is that you finger nails in the picture ? 

Ken


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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #8 on: August 06, 2010, 02:57:01 pm »

no way to increase the time on ni-cads, you could extend the time by running 2 batteries in parallel doubling the time but at the cost of weight.

you may be able to use a motor bike battery's in 12v that would give you extended run time but I'm not sure if the esc or motor could be used in such a way not only that there extremely heavy for a small boat.

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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #9 on: August 06, 2010, 02:57:52 pm »

ok...in free running it drains around 500 ma...but when in water the RPM reduces to a great extent, and it drains more than around 3 amps...motor heats up instantly..and blows off....all with my power transistor used in output stage...all pics are mine, in my profile....
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Tug-Kenny RIP

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Re: options for a 90 degree shift of final shaft..
« Reply #10 on: August 06, 2010, 03:01:17 pm »

ok...in free running it drains around 500 ma...but when in water the RPM reduces to a great extent, and it drains more than around 3 amps...motor heats up instantly..and blows off....all with my power transistor used in output stage...all pics are mine, in my profile....

Can you explain in more detail please. It sounds to me, an unusual speed control design.

Ken

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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #11 on: August 06, 2010, 03:06:03 pm »

if its getting hot that could be the draw of the motor, sound like over powered motor. add a few resistors in its path to lower the draw prehaps down to 1A? in and out of the water seeing how there small motors 6v also see if cooling them .. either water or air cool will help there life
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Umi_Ryuzuki

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Re: options for a 90 degree shift of final shaft..
« Reply #12 on: August 06, 2010, 06:41:50 pm »

Adding resistors would lower the voltage supplied to the motor, but will not reduce the amp draw.

Reducing the load is the only way to decrease the amount of amperage the motor will demand.

Rubber timing belts and pulleys make less noise than gears.  ok2
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #13 on: August 07, 2010, 07:01:01 am »

THANK YOU ALL....i use a motor speed controller based on a power transister,means, from a 12 volt, the voltage is reduced by an ic, LM 7805,or 7806,and it can only give around an ampere.so if i use this directly in my circuit, the ic will blows off even with an heavy heat zink.so i fed its output, to a power transistor,as 2N 3055, or MJE 13005,or BD 679,or 2sd 716..etc..a 470 ohms variable control is used between the base and out put of the voltage regulator.so i can simply control the total output vaoltage as my need...and i also tried with PWM,made out of ics like 555, cd 2014..even with those setups still i lose my motors...OHHH GOD...will you suggest any good motor that not burns out..? once i tried with a wiper motor of my car...but with all my craft weighs 7. 9 kilos....surely a mess...please advice me...i have tried with resistors, means 5 ohms, 3 watt,in series..but after a short time resistor start to burn...why these happening..i saw many photographs here is many members are using big motors directly on shafts...is it possible...?..will it work nicely...?  means without a reduction gear box..?
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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #14 on: August 07, 2010, 10:06:39 am »

Try building your own ESC 

Those with an electronics background can build this just from the drawing.

For the "rest of us" here's a simple procedure and photos of a finished controller.  We've built a handful of these, so we'll try to guide you.

If you have no idea how to solder or what a resistor is, and don't care to learn, you might be better off buying your ESC already made...

1) MATERIALS

-Old servo.  One with a broken gear train ("stripped") is ideal for this, as the servo electronics (amplifier board) will often be in good condition.

-Power Amplifier(s).  A power amplifier is basically a transistor.  MOSFETs will work for this purpose also.  The recommended power amplifiers are MJ11032, or 2N6282.  We've been using the latter, they come in a bag with NTE251 on the label.

Get these at your local electronics store (and we don't mean Circuit City!  Look in the Yellow Pages for a store that sells circuit components).  One (1) amplifier (and one resistor) will work; if you need to carry higher current, more amplifiers and resistors can be added (we'll discuss this more later).     For the MOSFETs, IRF530 are reported to work.

-Resistor(s).  500 or 1000 ohm will work.  From the same electronics store, or Radio Shack.

-Wire.  12 or 13 Gauge can handle ten's of Amps easily.  The flexible silicone wire works best.  If the electronics store doesn't have it, try the RC car section of the local hobby shop.

-Solder -Connectors.  Two pairs of whatever connectors you currently use on your batteries and motors: PowerPoles, Deans, etc.     -Optional: Circuit Mounting Board, Heat Sink, Zip ties

2) TOOLS

-Soldering Iron -Knife or wire cutter/stripper    -small Philips screwdriver

3) PROCEDURE

-Use the screwdriver to dis-assemble the servo case.     -Remove the servo gears.    -Cut the wires to, and remove,  the servo motor.    -Leave the circuit board (amplifier) and pot in place.  (The pot [potentiometer, or variable resistor] is the round thing with three terminals on the bottom.  In the servo it's used as a feedback device to determine amount of travel).

-Solder the components as shown in the diagram.  The wires shown in bold need to be the high gauge wire (12 or 13), that's where most of the current is carried.

-On the power amp, the two pins on the underside are closer to one end than the other.  The diagram shows the bottom side of the amp. The pins are labeled in the diagram as B (Base, or Gate), E (Emitter, or Source), and C (Collector, or Drain).   

-One of the servo motor wires is soldered to a resistor.  Wrap the other wire with tape.

-The negative terminal of the battery is connected to the negative wire of the servo connector.  In most modern systems, the arrangement is: yellow (or white) is Signal, then red (or orange) is Positive (the middle wire) then black (or brown) is negative).

Be aware that some older systems had odd conventions (e.g. Airtronics, red outside is positive, black middle is negative, then black (again!) is signal.  If in doubt find a wiring diagram in the radio system manual.

-Plug the servo connector into the throttle channel of the receiver.  This ESC does not have a BEC, which means that you need to plug a separate receiver battery (usually 4 cell NiCd or NiMH) into the battery port of the receiver.

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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #15 on: August 08, 2010, 12:36:23 pm »

OHHH..MY...MY...MY..god....Sir..i dont know how to thank you....i was searching for a circuit like this for years.....OHHHHH........i am going to buy these components from town....OOOOOOOhhhhhhhh........HI....Hi.....i will inform you after making this circuit....indeed........a million thanks again......
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #16 on: August 09, 2010, 08:32:15 am »

Good morning  Sir..and may i ask you one more doubt...?..i was wandering all over my towns for the mentioned transistors,and FETs...but as my native is not much advaced in electronics..so i can get only some popular numbers are..2N 3055 power transistor, 2SD 716, BD 679, CT 1061, MJE 13005, MJE 3055, and for mosfets are BUZ 11, and IFRZ411, and 471...can i use any of these here...?  if no, how can i make one....nheeeee....i am sad...please give me an advice...its a request again...oh..one more..can i use this diagram with all servo terminals..?means, i have two systems of radio as basic all 4 channel, from FUTABA, as YFM 4. and two from airtronics..SC6000..and one from DUPLEX...while examining all terminals are same in pattern..so i am asking that is internal diagram will copwith the same circuit...please give me a guidance..after that i have to make a good working model and runs for hours....
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #17 on: August 11, 2010, 09:53:25 am »

Good morning once again...and i compleated my speed controller..with a 2N 3055 power transister...and its working nicely...but one doubt..sir...if i am using it with lite motors, it runs smoothly...but when i use some motors like ,that you can see in my photos, big one...the power transistor heats up , up to a great degree..is it a malfunction...?  will it burns off...?   please....it works nicely except this phenomena....
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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #18 on: August 11, 2010, 01:25:23 pm »

heating up of the esc is normal just be cautious how hot it gets normally you are able to cool esc's you maybe able to mount a fan over the top and blow cool air over it to reduce the heat build up
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Shipmate60

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Re: options for a 90 degree shift of final shaft..
« Reply #19 on: August 11, 2010, 02:09:08 pm »

The last pic shows a 540 size motor, these will easily draw 5 amps.
What capacity is your speed controller?
On load this draw can increase to 7+ amps, will your speed controller be OK on this load?

Bob
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #20 on: August 12, 2010, 08:12:46 am »

Good morning and thanks once again...Sir  its 7 Amps..?  !!....HOO...i lost my power transistor while trying with this one...so i changed my motors again in to smaller, found in bobbin winders and car door locking mechanisms...it working nicely...I AM TOO THANK FULL TO ONE SCOLAR ,WHO TOLD AND GAVE ME ABOUT THE SIMPLEST CIRCUIT HERE, IS WORKING WELL....WELL...and i will add some videos in you tube, but i need one assistance to hold camera.so i am waiting for my brother once to take pics and videos...i am too happy after signing in to model boat mayhem...its a great community...of veterans..indeed..
                    And one more doubt...to you all what is the exact running time, for your cratfs, with a 6 volts 5 Ah battery, droping 1.8 amps around..?..any guidance...?  i got a motor, from a car fan, rated at 12 volts, and drops 1.4 Ah. it works well..but will it works with a 3 feet long craft..?  help...
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Shipmate60

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Re: options for a 90 degree shift of final shaft..
« Reply #21 on: August 12, 2010, 09:20:18 am »

If your boats require a 540 size motor you will need to have a higher power Speed Controller. or if electronics a problem even a resistance type controller.
The type that model cars used before going electronic.
They are simple and can be extremely cheap!!

Bob
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Prophet

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Re: options for a 90 degree shift of final shaft..
« Reply #22 on: August 12, 2010, 10:15:11 am »

i get around 15 mins on a large craft with similar battery setup , however i run twin 12v in parallel for extra run time
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rathikrishna

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Re: options for a 90 degree shift of final shaft..
« Reply #23 on: August 13, 2010, 12:27:51 pm »

thank you all...again..i am looking for a speed controller, as mentioned above...
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doorframe

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Re: options for a 90 degree shift of final shaft..
« Reply #24 on: October 27, 2010, 02:22:34 am »

Hi rathikrishna

Quote
thank you all...again..i am looking for a speed controller, as mentioned above...

Do you mean you need to be be able to handle more current? If so you can 'parallel' 2 identical transisters which will divide the current equally between them. I made some dodgy speed controllers for RC cars years ago (with 540 motor) but my control methods were unreliable. The method in the diagram above is far better than my attemps. As I was a television engineer I had easy access to power transisters. I used 2 X 8A transisters with insulated cases (which made it easier to bolt to the heatsync without shorting) fitted to 2 seperate heatsyncs. Drawback for me was no reverse!

By the way, your models are brilliant...especially your Puffer.

Regards,

Roy.
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