soft-start?? RC boat starter problem

[mrnedrub]

Howdy,

Can any one help me with a set up that will help me from breaking my E-starter(arrow shark)? The problem is as l see it is that the dc motor that drives the starter is hitting the fly wheel adapter and then braking it as the torque is to strong at the point where it engages the fly wheel adapter. There is a gap 95% of the time which is about 2mm before it makes contact with the fly wheel adapter and its this gap where the motor is able to start moving and gather speed (all be it very small) when it hits the adapter and "CRACK" there is the first hairline fracture and then another start or two and its off to the spare parts shop(again). So why not make the adapter stronger? Its a good question and one to which l am still waiting for from manufacture!! All thats been said is that "you need to be careful when installing as you might have problems" What the ....? So back to the point, if l had a soft start then the motor would start slowly for first 1-2seconds and then when engaged it would give full power.
l have seen a good idea where you use a relay an resistor but then l need a more power for this set up and its for a RC boat and am limited to power and weight . It has a standard 540 brusher motor which is quite normal for most 1/8 RC trucks etc. l am using a lipo 14.4volt 5000ma battery and this is controlled by a micro switch in-turn controlled by a servo. As l mentioned its a Arrow Shark E-STARTER 2010 model.

So with hands together and on my knees can any body help me?

Thanks Shaun nedrub

 

[SABorn]

I can not see how a soft start can give the torque you require to give the motor the initial kick over it requires.

What you really want is a decompression start, but we know that is not an option.

You could do a mechanical clutch of a sort to allow the electric motor to engage and then travel 1 full revolution before it cranked the motor.

This is done with 2 flat plates on the electric motor drive, one attached to the electric motor and one on the drive gear that engages the flywheel.
The gear drive plate has a bush that allows it to spin on the end of the motor shaft.
Both plates have a pin in them. As the plate on the motor spins it take 1 revolution for the pin to come around and contact the pin in the gear drive plate.
This allows for a soft engage onto the flywheel and the Clunk to take place in the plate clutch and not the drive gear.

A spiral spring is normally placed between the 2 plates so it returns the plates 360 degrees when the drive is disengage the spring also give resistance to allow the drive to engage.

Not quite the answer you were looking for but a system that has been used for over 100 years on equipment that has dog clutches to allow them to engage before the load came onto the shaft.

Pete.

 

[ronv]

The specs I see for that moter show a voltage of 7.2 volts. If you have 2 sets of batteries you coulod run it off of 1 set?

 

[InventionUnlimited]

Would it be possible to build a simple 2 stage, something like 0.25 seconds of low power to engage the clutch, then apply full power when the clutch is engaged. As it is a high torque motor im sure it could start the engine without having to shock start it.

 

[Michaeld1963]

Hi Shaun. Michael here from Townsville Queensland. Mate i had the same problem as you are having and i have smashed 2 flywheel adaptors so i modded the estarter as my cogs didn't look to be perfectly in line. I cut 2 of the tube spacers to get it all in line and i have ordered a CNC Billet Flywheel Adapter Upgrade for Remote Starter from the US $35 US dollars from an Ebay shop called Vapor Trails RC. Hope this will help you out as i got very frustrated with it . I have not tried the adaptor as i am still waiting for it to be delivered to me as i only ordered it about a week ago.

email me for info if you need to.
mdelforc@bigpond.net.au