Model Boat Mayhem
Technical, Techniques, Hints, and Tips => DC Motors (Brushed) and Speed Controllers => Topic started by: SailorGreg on May 28, 2019, 06:48:38 pm
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I ask the following question with some trepidation as it seems the sort of thing I should know, or be able to work out for myself, but I can't. So here we go -
Last year I built myself a Springer tug. Standard size and hull shape. I fitted a Speed 600 motor and a 20A Mtroniks Viper, because I had them to hand. The prop is a 40mm kort operating in a steerable nozzle (because I had never used a kort nozzle and fancied giving it a go). 6V SLA to provide the oomph. It soon became clear that after running for a while things got rather warm. The motor was too hot to touch comfortably, and the ESC warm to the touch. However, everything worked fine so I didn't worry. Later, though, I started getting brief losses of power (1-2 seconds), which I couldn't replicate out of the water on the bench. I assumed there was some mismatch which was causing the ESC to trip out (too hot?). Some brief research led me to a table on the Model Boats website which suggested the Speed 600 was really for planing boats (clue in the name I guess) and something like a 540 would be more appropriate. I bought a 540 from e-bay, fitted it and gave it a run. Same problem, perhaps even worse.
So - is my propeller too big and simply overloading the power train? Is the motor and ESC mismatched in some way? What do others use in a bog standard Springer?
Help!
Greg
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Your 540 could be one of several specifications. Many of them are very power hungry but unless you have a data sheet for it you won't know what you have. Maybe better to look at a 545 low drain motor but no doubt others will be able to advise you.
Colin
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Hi Greg,
I must agree with Colin. Motors are a mine field now, a good bit of research is needed before purchasing any nowadays. A number on the 'can' or advert means very little, and the self same motor if purchased as a pair can vary up to 15% in revs and draw to each other. In general a standard 600 johnson's motor will give all that is needed for a springer and a tad more. A 555 motor is cooler running and not so greedy. A 540 motor varies from a HOT race spec down to a hyper efficient dawdler. No doubt a hundred more opinions will arrive to advise you.
Step wisely and read the small print!!
Good luck
Pirate
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Using a 540 or 545 in a springer is a pretty standard choice, but because of the huge variety it's best to buy one from a specialist supplier who stocks motors for the job. The MFA 540 is commonly used, as are motors from decent model shops like Cornwall model boats and many others.
A p30 or p35 propeller will be about right, much larger and you risk overloading and overheating, as you found out.
I use an MFA 540 on 6 volts p 35 prop, it barely gets warm and I've never run the battery down.
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on my model I started out with a 385 motor, this was running very hot, so I upgraded to a 540 size, this draws approximately 1.5A and runs cool to the touch, this with a 35mm prop, I believe I used the low noise 5 pole motor.
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I fitted a Speed 600 motor and a 20A Mtroniks Viper, because I had them to hand. The prop is a 40mm kort operating in a steerable nozzle (because I had never used a kort nozzle and fancied giving it a go).
SPEED 600 + 40mm prop. Thats the clue. Motor intended to drive a small prop fast, driving a larger prop than intended and having its natural speed dragged down severely. Classic recipe for an overheated motor and short battery life.
From the original Springer thread on RCGroups (where it started) -
Motors, any 500 series motors will work.
Try using 27 turns or higher.
Many modlers will recommend a 45-55 turn motor to maximize runningtime and minimize heat.
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There are many 540-sized brushed motors available for rock-crawlers, with anything upward of 27 turns. These can be had for less than £10 if you look on E-Bay. That way you'll have a pretty good idea of what you're getting inside that otherwise anonymous metal can and thus what sort of performance you'll get out of it.
DaveM
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Thanks all. I have a 55 turn motor on the way and will probably get a 35mm prop as well. I will report on success, assuming it is successful.
Greg
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Greg
Pardon me if you already know this but if you're still going to use the Kort then stay with the 40mm prop, too. That motor should easily be capable of spinning it without undue current drain.
DaveM
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Thanks Dave. I thought I would try the 40mm with the new motor, and then a smaller prop if I still had problems. I am grateful for your confidence-building advice. :-))
Greg
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Sounds like a good plan! And you're welcome.
DM
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My Springer, a Models By Design Hull and Kort Nozzle with a 40mm Kort Prop driven by a 540/1
powered by 6V SLA and Mtroniks 20A esc has been
running up and down the lake as a rescue vessel
for the last 8 years. I fitted a water cooling coil
but I don't think its doing a lot as rescues involve
backing and tooting so not much through the pickup. 2 hours or more each session has never used the
batteries 2x4.5 A 6V SLA to low volts.
Today, one push back and one yacht in irons turned through the wind.
Ned
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Quite a lot of precision about motors here but very little re the load (propellers).
Are you all using the same prop, eg 3 blade 40mm Kort PropShop prop, or are some using 4 blade & others plastic?
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Well mine is a 4 blade Raboesch prop running in a Models by Design Kort nozzle.
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That 55 turn crawler motor will have oodles of low end torque, just right for a 4 blade brass prop. The 4 blade brass prop also explains your problems previously with 540/600 motors.
There is much advice above, most of it vague unfortunately. Just using a '540' wont guarantee a good performance, just using a 5 pole version also no guarantee. What you need is good, hard advice, based on experience. Netleyneds advice regarding the MFA RE540/1 is spot on. This motor is a fairly lightly wound, medium power motor, ideal for scale use, up to a 40mm prop. MFA also produce something called a RE540LN, which, just to add to the confusion, has a can length more like a '550' type motor, it is also a 5 pole motor, which is lighter wound than their standard 540/1. This is slower and has greater torque, so is once again good for slightly bigger props, I would say up to 45mm at a push.
The new crawler motors coming onto the market now are brilliant direct drive scale motors, the more windings the more torque. I have a 70 turn motor, and the torque is incredible. I think it could turn over a 50mm prop with ease.
As a simple rule of thumb, the more windings a motor has, the more grunt it has and the less it will be loaded down with the wrong prop. Too much load, too high current. The problem is many motors dont offer this advice. I often resort to looking into the cooling hole of the motor. If it has many thin windings it will be slower but more suitable at lower speeds. If it has less windings that are thicker, it will be faster, more ampy and run hotter.
Different motors for different jobs..
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If we add some detail the Integy 55 turn 540 crawler motor is around 1100kv whilst the MFA 540/1 is around 1250kv and the RE540LN I believe has a kv of around 500kv.
A 70 turn crawler motor has a kv of around 875kv.
The quality of the motor (particularly the magnets) has a large effect on power & efficiency.
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An Integy 55T in the water with a 35mm 3 blade Raboesch warship prop and 3S lipos pulls 9.9 amps turning at 8,800 rpm.
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An Integy 55T in the water with a 35mm 3 blade Raboesch warship prop and 3S lipos pulls 9.9 amps turning at 8,800 rpm.
It would be interesting to know what sort of current the same set up pulls at 6v/7.2v/7.4v, which would be the voltage band most smaller scale models would be operating in.
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If we add some detail the Integy 55 turn 540 crawler motor is around 1100kv whilst the MFA 540/1 is around 1250kv and the RE540LN I believe has a kv of around 500kv.
A 70 turn crawler motor has a kv of around 875kv.
The quality of the motor (particularly the magnets) has a large effect on power & efficiency.
These all seem to cover scale needs well. What we now need to know is the equivalent performance of the motors I often see fitted in scale boats, that really have no place in them. The Johnson 600/Vision 600, Tamiya type 540 motors, some of those more bitey 5 pole 545s...just as a good point of reference.
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Hi Sailor
I am using 540 rock crawler motors(55 and 60 turn) in my Hellen fishing boats with 3blade brass props (50mm and 60mm).
Running 7.2 volts with no heating problems at all!!!
The motors are from Banggood.
I have a 80 turn one but its a bit too low rpms on 7.2 volts, but, OK on 12 volts.
Canabus
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It would be interesting to know what sort of current the same set up pulls at 6v/7.2v/7.4v, which would be the voltage band most smaller scale models would be operating in.
Re Integy 55T & Roboesch 3Bl 35mm on 11.1v (3S)
I would expect (not proven) that at 7.2v the answer would be around 3.5 - 4amps and around 6000rpm which would give around 50% the static thrust for 25% of the power consumed (watts). I would love to see measured data to confirm/ deny theses numbers.
At 6v the answer is slightly complicated as scale model boat owners often use small lead acid batteries which can have a significant voltage drop if asked to provide more than half their mah rating ( eg 3amps for a 6ah battery).
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It would be interesting to know what sort of current the same set up pulls at 6v/7.2v/7.4v, which would be the voltage band most smaller scale models would be operating in.
Well a Graupner 600 eco on the same prop and 9.6 V NIMH came out at 5,700 rpm and 6.4 volts.
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Hi Sailor
I am using 540 rock crawler motors(55 and 60 turn) in my Hellen fishing boats with 3blade brass props (50mm and 60mm).
Running 7.2 volts with no heating problems at all!!!
The motors are from Banggood.
I have a 80 turn one but its a bit too low rpms on 7.2 volts, but, OK on 12 volts.
Canabus
Do you know the amps that you are pulling?
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As an aside & hoping that this might help someone.
A brushed motor acts as a generator just as much as it does a power source so if you want to know the kv of a motor & you have a known rpm source - a drill often has a published rpm - and a voltmeter it is easy to appoximate a kv. Drive the motor with the drill and measure the voltage that the motor develops. So if you have a 1400rpm drill and the output voltage is 1.6v you have a 1400/1.6 = 875kv motor.
This will be approximate & you obviously would need a lot of rpm with a high kv motor to get an reasonable estimate but it works for scale type motors at least it gives you some idea of what type of motor (scale v racing) you have.
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I am constantly surprised at the mismatches of motors and props in scale or scaleish model boats which often result in either overheating, poor performance or both. Any significant heat in a scale model represents inefficiency somewhere in the propulsion setup.
My Fishery cruiser can be seen at way over scale speed in the video on the 2019 Mayhem page (55 seconds in). This boat is four feet long and weighs around 10lb (4.5kg). It is powered by two low drain 380 type motors geared down about 2:1 via belt drive to 11 inch M4 shafts with 35mm props on the end. Battery is a 7.2aH Nimh pack.
At full speed, using both motors the total current draw is just 2.5 amps in the bath, probably a bit less on the open pond. Nothing even gets slightly warm.I haven't measured current draw at cruising speed but it is probably under 1 amp per motor.
There are often huge efficiency advantages in gearing the shaft down as it helps moror revs to remain high while prop speeds stay relatively low. A win win situation.
Colin
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Do you know the amps that you are pulling?
Damn, a typo > Well a Graupner 600 eco on the same prop and 9.6 V NIMH came out at 5,700 rpm and 6.4 amps.
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I am constantly surprised at the mismatches of motors and props in scale or scaleish model boats which often result in either overheating, poor performance or both. Any significant heat in a scale model represents inefficiency somewhere in the propulsion setup.
My Fishery cruiser can be seen at way over scale speed in the video on the 2019 Mayhem page (55 seconds in). This boat is four feet long and weighs around 10lb (4.5kg). It is powered by two low drain 380 type motors geared down about 2:1 via belt drive to 11 inch M4 shafts with 35mm props on the end. Battery is a 7.2aH Nimh pack.
At full speed, using both motors the total current draw is just 2.5 amps in the bath, probably a bit less on the open pond. Nothing even gets slightly warm.I haven't measured current draw at cruising speed but it is probably under 1 amp per motor.
There are often huge efficiency advantages in gearing the shaft down as it helps motor revs to remain high while prop speeds stay relatively low. A win win situation.
Colin
Lovely model.
An MFA 385 is 975kv which with a 2:1 reduction (effectively a 487kv motor) is about the same as one of the low rpm 5 pole 500 (555) series motors. Whether it is better, has more power output/ torque or uses less power input???????
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Thanks to everyone who has pitched in on this. I (and, I hope, some others) have learnt a lot, not least that buying motors is a real minefield!
There are lots of gems of information on this thread that I for one will try and save somewhere. But I am still rather confused - Colin says above that he has 2 380 motors in his Fishery Cruiser geared down 2:1. Fine, but there is a plethora of 380s available, not all the same. Certainly a glance at e-bay shows lots, many without any technical data beyond the can size. How would I know what to buy to replicate Colin's setup? (Sorry Colin, not having a go at you, just using your post as an example.) And his motors are low drain - what does that imply for turns, revs, torque...? (Rhetorical question, just me musing!)
The more I find out, the more I realise I don't know. Yes, a real minefield!
Greg
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Thanks to everyone who has pitched in on this. I (and, I hope, some others) have learnt a lot, not least that buying motors is a real minefield!
There are lots of gems of information on this thread that I for one will try and save somewhere. But I am still rather confused - Colin says above that he has 2 380 motors in his Fishery Cruiser geared down 2:1. Fine, but there is a plethora of 380s available, not all the same. Certainly a glance at e-bay shows lots, many without any technical data beyond the can size. How would I know what to buy to replicate Colin's setup? (Sorry Colin, not having a go at you, just using your post as an example.) And his motors are low drain - what does that imply for turns, revs, torque...? (Rhetorical question, just me musing!)
The more I find out, the more I realise I don't know. Yes, a real minefield!
Greg
The MFA385 is the standard low drain 400 sized motor. As you say there are lots of much hotter motors that look the same (the Graupner 400's being the standard example).
Without meaning to critisize anyone there is a lot of partial information when it comes to model boat drive systems. You have highlighted motors but equal problems exist with propellers. Plastic props are generally designed differently to metal props & there are at least 3 very different plastic prop design - s type, x type and 3/4 blade scale. There are even more variations with metal props with 3, 4, & 5 blade props of numerous different designs. These can have vastly different performances.
So if someone tells you they (as an example) have a 540 motor driving a 40mm prop & it pulls 8 amps you have a lot to find out before that becomes useful information.
There is also the problem that things are often not linear. Going from a 40mm prop to a 45mm prop of the same design might well double the power required to drive it from the same motor etc. Going from 2S to 3S will not increase power in & out by 50% but by a much larger factor whilst going from 3S to 2S will often save a very overloaded motor at the expense of power.
I would equally be wary of the often repeated old adages like "keep the prop diameter smaller than the motor diameter" for exactly the same reasons.
My rule of thumb is to be very motor kv aware and where possible fit a larger motor that will not be working as hard. Gearing does the same thing.
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Greg
What Colin omitted to say is that a 380 and 385 are as alike as chalk and cheese, despite their physical similarities.
A 380 is a 3-pole motor which is very fast-revving (about 26000), usually runs on a maximum of 7.2v and should never exceed 10A. They are the ones which are often sold as Speed 400 motors. I've only ever used them in a Glynn Guest-designed airscrew-driven swamp boat and a 20" all-balsa semi-scale Swordsman. With a 25mm 2-blade bronze prop that thing went like greased weasel pooh!
A 385 is a 5-pole motor which can be run up to 15v, strangely has slightly less torque and is much slower. However at its maximum efficiency it draws only 1A c/w over 5A for the 380.
MFA's website has excellent data sheets on all of their motors, which include their "stock" 540/1 as well as what they term "noise attenuated" versions of the 540 and 385. Here's the link https://mfacomodrills.com/motors/motors.html (https://mfacomodrills.com/motors/motors.html) Just click on the motor you're interested in and it will download a datasheet in PDF format.
Dave M
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Quite right Dave & Greg, I should have made myself clearer, the motors are 380 size and fitted a long time ago so I can't recall where they came from which is why I described them as 380 type. They are definitely low drain and presumably 5 pole. They work very well in my setup. Props are 35mm standard scale 3 blade brass Raboesch.
Colin
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If anyone wants to know the outcome of my new motor fit, read on -
I purchased one of these (https://www.amazon.co.uk/dp/B07QNW49GN/ref=pe_3187911_189395841_TE_3p_dp_1)and left everything else the same - 40mm kort prop, Mtroniks 20A Viper ESC, 6V SLA. I ran the boat today (in between the rain) and kept it at full power for about 20-25 minutes. Previously this would have resulted in a very hot motor and intermittent losses of power. Not this time. The motor was certainly warm/hot to the touch, but not as hot as previous motors, and there was no interruption of service. I do believe the problem has been solved! :} :}
Thanks again to all who offered advice and information. I am slightly better informed on motor technology and much more aware what to look for when buying anything new.
Happy sailing
Greg
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Greg
That is great. Do you know how any amps your are using?
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No. I am not sure how to measure that under load. The 20A ESC didn't get even a little warm so I guess it is operating well within its capability.
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No. I am not sure how to measure that under load. The 20A ESC didn't get even a little warm so I guess it is operating well within its capability.
I have one of these for that purpose. It's small enough to be carried on-board. No doubt there are others available e.g. from our inscrutable little friends... http://www.4-max.co.uk/wattmeter-budget.htm
(http://www.4-max.co.uk/wattmeter-budget.htm)
DaveM
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Hi all, many years ago i built a 16 inch loa Swordsman. Power was a MFA 380 with 1 :2 gear reduction onto a 30 mm S series black prop running on 5 nicads (ex camera).
The power consumption was about 40 watts so current over 6 amps. The speed was dramatic and at full speed just 2 or 3 inches of hull in the water.
regards
Roy
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IF your SLA is the popular 4 or 4.5 ah 6 volt battery, you can estimate the current to be around the 5 to 6 amp area.
A lighter 7.2 volt NiMH battery would make a dramatic difference.
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I really like to know the current (amps) consumption of my motor/prop combination before I put the controller into the circuit - it is much cheaper that way! Battery to ammeter/ wattmeter to motor (which is attached to shaft & prop & in the water).
If you have the controller in circuit you can always start at low throttle which is also low amps & gradually ramp it up to full throttle keeping an eye on the readings. This is only a really bad idea if you dramatically overloaded the motor.
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Ok I have been making model boats of differing size / type /style for a fare few years and prior to that model aircraft .
Since taking up model boating on retirement I have always bought Action kit as I found that when I had issues and learning the ropes D M was a sound source of unbiased advice .
I have bought in total some 53 assorted items from there range and most have served me very well over the past 12 years of boating .
Whilst not always popular , I tend to speak from the shoulder and if asked try to help others .
I must admit that it is only recently that I have been a follower of this Forum and taken the time to read through the items that could have helped me prior to last weekends event .
Amongst others I have a Tug which is both great fun and helps drag less careful members models at our club back to the shore line .
On this particular day I noticed that my Kort nozzles were very slightly offset , and thought ok I will put a little trim in when out on the lake , which I did , and all seemed well and after a good 1/2 hours run around the edges stopped in the centre and chatted to others ......as you do %)
When I restarted the Tug and headed for shore she seemed hard to steer in a straight line and was very sluggish compared to her usual speed but managed to get her ashore [ incidentally this model has worked very well for over 14 months with only minor upgrades but has not been used during the last eighteen weeks of lock down .
When she reached shore and I berthed her in her cradle prior to wheeling her up to the assembly area I noticed the dreaded Bakelite aroma and new things were going to get worse , and when the superstructure was removed I noticed that the rear of one of the motors was partly melted . :o
When I carried out the autopsy I removed the starboard 540 geared motor and clip on cooling fan and binned them as they were not of any further use <:( and ordered replacements and upon receipt and fixing found that only the Portside units functioned .
checked fusing which seemed fine , no lose fittings , so as I had a spare P94 which had been refurbished , fitted that and hey presto everything worked perfectly again
Now , I ponder the fact that was there an issue with this ESC that eluded me [ purchased in 2010 ] that having not been noticed slowly got worse and then threw the towel in ? {:-{
Should I have smelt a rat and not gone on the water :(( .....still at least I was saved the embarrassment of being towed back in
Has anyone else had this experience ?
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This sounds more like something has got caught in the propellor - weed, poly bag etc which has then overloaded the motor making it overheat and in turn overloaded your speed controller letting out the magic smoke. The extra drag of something in the prop would affect steering as well and I suppose it's possible it could fall off without you noticing as you lifted the model out.
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Well Ralph , anything is possible I suppose , after all it is a Private Carp fishing lake and the banks are trimmed occasionally so yes that is a possibility but not one that the club have had before that I know of and the club has used it since 1950 when it started
The Lake is feed [ amongst other sources ] by surface water from the A14 draining off and was a gravel quarry , very murky , and at least 5-7 metres deep in places to my certain knowledge , none the less something to be avoided if possible eh .......
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Now , I ponder the fact that was there an issue with this ESC that eluded me [ purchased in 2010 ] that having not been noticed slowly got worse and then threw the towel in ?
Electronic speed controllers don't wear out or become sluggish, Ivor - certainly not in my experience. If it has been working well for 14 months then there's no reason why it should suddenly stop working without some external interference. Motor cases melt because they overheat, and that's usually caused by an excessive load. That in turn will lead to excess current drain and probable damage to the ESC.
I agree with Ralph's suggestion that something fouled the prop. Kort nozzles are more prone to this because weed or a polybag can easily become jammed between the prop and the nozzle. This would also explain the steering problem. Incidentally if you suspect that something has fouled the prop then a quick burst of full reverse often clears it.
Dave M
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Thanks for the response Dave ...appreciate it .
If I implied that the product was faulty let me correct that here and now , and the comment that I bought it ten years ago should allay that fear as it has worked very well in a 6ft aircraft carrier driving two 800 motors without batting an eyelid and other models requiring an ESC that have passed through my workshop , so it is a prov-en animal to me and feature rich ....an excellent selling point ..... and it will be winging its way back to Component -shop for refurb ....just like the one which was installed to get me mobile again .
My comment was more self critical of ME thinking that the misalignment could be offset on the transmitter when I saw that the previously straight alignment of the twin Kort's had changed :o and as I hope I stated to others I seem to have spent a lot of money over the years on products that I have found to be worthy of use [ and that total doesn't include all the ancillary cables / connectors / meters , motors / clips , catches / led's / heat shrink and servos that have been used in fit outs from Iain !]
It seems likely that it could have been some type of flotsam that was ingested in the starboard Kort , but again as I said this is a first and came as a shock , but as I said as recovery tug , it could have been worse to have been recovered myself O0
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A truly annoying thing about some types of weed is that they do their evil, then fall off just as the boat leaves the water.
Usually a motor with a melted end cap has as its heat source a bearing giving up or the brush gear getting tired and generating more heat than it should. I've seen a heavily overloaded motor (a 280 running on a 3S LiPo driving a 35mm 3 blade prop) burn its label off and save the boat further harm by melting the solder on its tags without harming the moulding. Probably a re-invention of the fuse, that.
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Thank you for that gem Malcolm , and glad to see that I am not alone in this situation , and hope that my choice of motor / prop ratio stands the test of time , which from February last year it has , with guidance from others who know better than me O0
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I appreciate it is a matter of choice but I always fit a fuse between the motor and ESC to protect the motor in this sort of situation. On a twin screw model I have a master fuse in the positive lead from the main battery(s) and subordinate fuses between the motors and their ESCs.
It's the easiest thing in the world to foul a prop and the fuses cost pennies. It is easy enough to find the stall current of the motor with an ammeter on the bench if it isn't already published in the specs (don't jam the shaft for more than a second). I also measure the motor draw under load with the boat stationary in the water as that is the most you are likely to experience on the pond. The fuse should be a bit above this value to allow for start up spikes but below the motor stall current.
My Dad worked in the electricity supply industry - he was a great believer in fuses and so am I.
Colin
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Hmmmm Colin .......this is going to ruffle some feathers I fear , but every boat I build has a P92 fuse board as standard for the very reasons you elude too and in this case it should have been protected but there again perhaps the 15 amp fuse was to high as it was in line for two 540 2.5=1 motors and two clip on cooling fans as per the C /shop motor case size .....which up to now have been fine.....or perhaps an accident waiting to happen ;D
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Interesting discussion on resetable fuses here: https://www.modelboatmayhem.co.uk/forum/index.php/topic,64475.msg683269.html#msg683269
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Thank you Martin , and having just read through this worthy discussion I am of the opinion that if these self resetting fuses are what is claimed why are they not fitted as standard in the distribution boards that Action currently sell :o
I am not looking for an argument with either Iain or Dave but to idiots like me these sound a great idea and if they cost an extra fiver each they would be a good idea and I for one would use them However If I decide to fit them and sink my model and then start pointing fingers at the supplier who reply by saying that They do not fit them as standard and as such I caused the issue which resulted in the loss ..........where do I stand then
IF as claimed by the posters on that thread they have been around a long time and they are the dogs whatnots why haven't "Component -shop" fitted them as standard .....as they could be argued as a cost effective selling point that not only protects the model but resets itself ...........it sounds like a minefield of litigation that they would prefer to avoid
Other than the incident mentioned by me I have lost two models ......one caused by me fitting a receiver bought on eBay which WAS NOT a genuine Spektrum product which having had the TX serviced by the suppliers [ so that was not the cause ] and the correct RX was four times the price I paid for what I thought was a genuine RX I wrote off a model in excess of 1K [ which unbeknown to me was insured on my house contents policy and I was paid in full ,.....and the other was a vac formed hull cut in half be a speeding modeller which sank ! ,but it focuses your mind on Who was to blame !
If I risk anything ...thats my problem ........however........ if I fit purpose made equipment supplied for a specific purpose[ supplied with specific types of Fuses ] and then alter it ......thats also my problem and I suspect I would not have leg to stand on
or am I wrong again !
Anyone care to give a view on that side of things .....as that would be very useful
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Can't you just substitute resettable blade fuses for the ones supplied if that is what you want? They appear to cost £4-£5 each for either manual or auto reset options from a quick look online.
I probably would stick with the standard types as I have only infrequently experienced fuses blowing. Why pay more for something you are not likely to need? If you do get weed around the prop then an auto reset isn't likely to get the boat moving again so there would seem to be little benefit in the more expensive option. You can buy a lot of standard fuses with a variety of options for the price of a single resettable which is only good for one value.
Horses for courses and if you buy the ACTion P112 you can choose the option you want.
Colin
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Already on board Colin but thanks for the well intentioned thought dear Sir . :-))
I this particular Tug I have both fitted and the lights sounds are fused on the P112 which is slaved / supplemental to the P92 to which the motors are fitted lower in the hull adjacent to the SLA batteries in this Tug .
The P112 is a great bit of kit I think and enables you to fuse every item drawing current and if like me the "Extras" are housed in the superstructure means less cable runs and keeps it tidy added to which it has provision for power meter take off to fit current voltage of battery and current drawn on a meter display set into the bridge of the model ;)
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I have just reread this thread again in case I had missed a vital point that would have answered , but not found yet .
There are obviously many experts and as many opinions on these subjects , and accordingly I have also fitted fuses between the ESC and the 545 geared motors as it seemed a logical step , and I did not have the room in the space to fit two P95.1units .
This model which as said earlier is the rescue Tug I use at the club and whilst is serves me well [ apart from the ingested debris mentioned earlier ] but according to previous opinions may not be perfect ......even though it has worked consistently well in its as built state for a few years without mishap
Motors MFA 540 2.5=1 x 2 cooled by 2 x 36mm cooling clip on fan units
ESC P94
PDP P92 + PDP P112 x 2
SLA 12v 14 Ah x 2
BPB P103
Bronze 52 mm 5 blade Kort props x 2
Matching. Aluminium Kort Nozzles
30/33 Bow thruster
ESC P93
Servo Morph P96
80g metal geared servo
Sound system P110
Amp P97
Spot lights , Nave lights , led flood lights, radar motors , fire monitors x 2 internal radar monitors and lighting .
All fitted within a modified MMM tug FG hull of Ayton Cross OAL 1035mm Beam 365mm converted to a Damon ASD 2810 1/32 superstructure
She pulls anything and often tow's a floating model recovery boom some 200m long if needed to encircle the defective vessel and bring it home safely .. :-))
So that's my set up and if I could post a photo of her that small I would but lack the ability to meet the Forums size restriction
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Probably teaching my grandmother to suck eggs, but have you checked/cleaned the prop shafts? Pete
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Sure did , and whilst replacing the burnt out starboard motor I cleaned both prop shafts and gave them both a liberal coating of White Lithium grease as I had done at the beginning of the season Pete , and always fit new Brass nuts and thrust washers as they are a soft metal liable to rounding off when tightened up , but rather do that than lose a bronze prop as they ain't cheap to replace in pairs :o
I also keep a off cut of plate glass a role the prop shafts over them to check for distortion and any wear on the bronze bushes on the shafts [ which in hind site I wish I had fitted with oilers .....but hey ho ....
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We mismatch props & motors because we don't know any better. It is difficult to see why there is a problem, we don't know so how do we know what doesn't work. To newcomers a 540 is a 540 a 380 is a 380, how on earth are we supposed to know the different types if they are called the same thing. If we are building scale we go for the size prop that look right on the boat, what motor to use, how do we know.
It doesn't help us a lot when so called 'advice' is really just taking the mick out of our ignorance. I asked a serious question on here earlier in the week and the only answer just mocked my prop/motor combination without giving any constructive help. Don't forget you all had to start somewhere.
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as ever was the case Beejay ........the price of knowledge eh ..
I got with what works for me ....but often an expensive route sadly <:(
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We mismatch props & motors because we don't know any better. It is difficult to see why there is a problem, we don't know so how do we know what doesn't work. To newcomers a 540 is a 540 a 380 is a 380, how on earth are we supposed to know the different types if they are called the same thing. If we are building scale we go for the size prop that look right on the boat, what motor to use, how do we know.
...back in the day we read books and magazines and worked out what might be similar or word elsewhere -and I still recommend any beginner do so also! The internet is a vast resource but is also "dumbing down" intelect because never has it been so easy to look things up, but seems more difficult to encourage learning and research v.s. instant gratification. That and very few seem to learn from experience now, making a mistake is a crucial part of learning but now we can't seem to do anything without asking first and obtaining a majority answer before we try anything at all. Makes me wonder how we ever get a bottom wet sometimes these days.
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I certainly learn by experience, especially if has cost me money.
I think one the the problems we have, especially in the last few months, we have had to buy almost exclusively by mail order. There is little advice available along that route.
When I was first into model boats, about 40 years ago, you generally bought what you needed from your local model shop. This was usually run by a wizened old fella who knew it all and more to the point was willing to share it all. That seems to be a thing of the past unfortunately.
With the internet & 'electronic' mail order we have more choice than we've ever had, which is good, however we struggle with informed choice, which is what we really need. Even on an excellent forum such as this, advice is often contradictory and the world & his wife is quite willing to tell you that you are wrong, often sarcastically. People seem much less willing to actual share good advice based on experience.
Lest you all think that I am slagging off the model boat community, I'm not, these attitudes are rife across a whole range of hobbies. Hobbies of all stripes seem to be dominated by the "I wouldn't do it like that" brigade, while jealously guarding their hard won knowledge.
Personally I have never had that attitude, I have been a First Aid trainer most of my adult life, my remit has been to share knowledge, and that applies to my hobbies too. And in life in general too, I write pub quizzes, even that is sharing my knowledge with one & all.
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I don't know which online shops you use, but I have to say that my, admittedly limited, experience is that if you call these people and explain what you are after they are very happy to give advice. I have in the past had excellent advice from Cornwall Model Boats and others when I was uncertain about buying. If folk are keen to sell to you, they will usually invest some time to talk to you and help you on your way. And if the online vendor doesn't provide contact details, perhaps it's best to find someone who does.
Greg
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Well lads at the risk of having a good slapping by the mod's for being off topic , I would respond thus ..
In my post yesterday at 17.15 where I list whats in my Tug , and the foregoing comments in this post about prop size ..motors ..esc you can clearly see that most of the "I don't recommend this that or the other " by other modellers has been broken or circumvented .
As stated ....the mix in my model works well [ unless your prop swallows debris ] and I have been using this set up without mishap
I tend to agree with Greg's comments about retailers assistance or the current lack of it nowadays......alway's assuming you can get hold of them that is , and yes I tended to take as Gospel two retailers advice who helped me a lot but currently it seem's to have to much to do now days whilst others seem to cope in-spit of the current situation .
The most helpful Guy I ever came across involved in modelling has retired now and regulars will know of whom I speak .....bless him..... and substitutes are like hens teeth sadly , but one can only live in hope that they..... in time ...recall that these people who seem to annoy them are the ones who we are trying to put money in their collective company coffers and when they climb down from their ego will see the error of their ways and expand their business
Right I will get off my hobby horse now and thank the fellow members who have taken the time and trouble to share their experience and advice with others ....all with the best intentions and good will ......I thank them ALL :-))