Prop and motor help

[matt ChurcherParticipant @mattchurcher85021]

Hello. Is there anyone that can help me with some technical help with my Baitboat. I have a torpedo 850 and wondering if the motor has had it or there could be other problems lurking

[matt ChurcherParticipant @mattchurcher85021]

Asking tech people

[neil hpParticipant @neilhp]

you dont give the techies anything to go on………..perhaps if you explain what is going on, or not, what electronic equipment you are using………and what does and doesn't work, then maybe you have a chance of getting an answer to what problems you havnt told us about.

domt forget photos of your set up………..nothing worse than trying to diagnose what is wrong if you cannot see what might be a simple problem to solve

[matt ChurcherParticipant @mattchurcher85021]

Hello again. Apologies for lack of detail. I guess I was looking for a person before I went into too much detail. Happy to pass more info on though.
so I have had a Baitboat for around 18 years. It is fitted with a torpedo 850 but run on a 6v double battery. I guess the design was for slower and more length of power this way. Over the years the boat just seems to be so much slower and I am wondering if the torpedo motors do eventually wear out as such. I have added some more constant weight by way of bigger batteries but the power issue seems to be more intermittent. Sometimes I think it’s fine and other times it’s very slow indeed.
the boat sat in a shed unused for around 6 years. After reading some of the posts on here I am wondering if changing the prop may help. I did have a kind chap help me look over the boat and I remember him saying the motor is drawing a lot of current. Not sure if this is a sign the motor has had its day🤷‍♂️
I guess I don’t want to buy stuff if it won’t change the performance. Is the a way I can check the batteries or the motor easily??

happy to send pics

kind regards

matt

[Richard SimpsonModerator @richardsimpson88330]

Hi Matt and welcome to the forum. Unfortunately, as Neil has already indicated we are still very short of detail to be able to offer much in the way of constructive help.

However in very general terms motors tend to be fairly robust and rarely fail. Having said that brushed motors may eventually require attention to the brushes or commutators as dirt can build up and will affect performance. What is probably far more likely is the battery condition. If these are not kept fairly regularly cycled then they can deteriorate and cells can fail. Again we are a bit in the dark as we don't know what type of battery you have. The trouble is that it can be very difficult to identify a problem with the battery without a good charger. Simply charging it up and trying it tells you very little. If it is a lead acid type, which I am assuming it may be, then leaving it untouched for a long time will almost certainly lead to cell failure and a lack of ability to hold charge, Again you say you change the batteries but we don't know anything about them to be able to say.

You have also said nothing about the speed controller that is being used or the radio set up that is in the model, both of which may be potential sources of problem. The least likely to me would be the propeller because it used to work so why shouldn't it now, unless there is a chunk missing!

If it was me the first step would be to connect a known, good, charged battery directly across the motor terminals, with the motor disconnected from the propeller shaft, to see if the motor spins OK. If not maybe the brushes and commutator need a clean up. If it runs OK then the challenge is elsewhere. Does the propeller feel free when not connected to the motor etc.

Photos would still be very useful so please post them.

[neil hpParticipant @neilhp]

those 850's are very robust long serving motors that give very little problems.

one of the clues to a possible problem is that you say the boat was left for 6 years unused.

before you start spending money on new electronics…………disconect the motor from the prop shaft and see a] how much the shaft is moving up and down the tube as it might be binding when being thrust against the bearings and b] how free is the shaft inside the tube.

i have a feeling that after it has been unused that length of time, the shaft might be partially seized inside the tube…………an indication that the motors are drawing a lot of amps and getting warm.

if the shaft and propellor dont spin very freely, you will have to both clean the tube out using some whte spirit to disolve the grease/oil inside the tube, and also if the shaft is rusty, clean that all off using 180 grade carburundum paper.

i had to do the same with one of my boats i hadn't sailed in six years only a moonth ago.check this first.

 

Edited By neil howard-pritchard on 19/08/2022 01:59:36

[matt ChurcherParticipant @mattchurcher85021]

Hello

ok so hopefully I will be able to add some photos to this post. I believe I may have discovered part of the problem. I played around with a volt meter and I may have purchased some bad batteries. I have looked after these well and yet the voltage drops rapidly under load. I used some of the old 6v 7ah and the speed in and out of the water was acceptable. A question I do have that maybe you all can hopefully answer I’d where can I get some decent batteries that will last well and also as I said I am running the 850 on a 6v system ( purchased this way) would I be better keeping to this system to get better length of use out the batteries or would putting 12v but reducing the speed controller to half power say make the boat a little faster and prolong the battery? When I go fishing it can be over a few days with varied use. That said the boat is used for around 10 mins at a time every few hours say.

[matt ChurcherParticipant @mattchurcher85021]

[matt ChurcherParticipant @mattchurcher85021]

[Richard SimpsonModerator @richardsimpson88330]

For the amount of use you are giving it I don't think using 6V at full throttle or 12V at half throttle makes a great deal of difference. I would choose the battery that suits your ballasting requirements best.

Batteries available from:

Component Shop

Also note that your rudder linkage seems to have gotten itself out of whack a little. You need to turn on your transmitter and then the model and make sure the rudder stick is centralised. Then remove the arm from the servo and rotate it so that it is roughly parallel to the rudder stock arm and reconnect the servo arm to the servo. You can then trim the rudder with the trim button on the transmitter to get it perfectly midships. As you have it you will get very little movement to Port and a very large movement to Starboard.

[neil hpParticipant @neilhp]

i still think it could partly to do with your shaft, and now having seen the photo of the motor ,coupling and shaft/tube………….there seems to be absolutely no play between motor and shaft, and when you open up on the throttle the thrust from the motor pushes forward and the far end of the coupling from the motor end then will bind on the prop tube causing friction and a binding of the motor/coupling and and shaft will slow the motor down with friction and increase amps used from your already dodgy batteries.

[neil hpParticipant @neilhp]

if you watch this video of one of my boats, you will see the trust of the motor pushes the coupling [same as what you have in your bait boat] towards the end of the prop tube and thus giving room for your shaft and coupling to run without binding.

on your boat there is actually no space at all for allowing and movement, and your 850 is a lot more powerful than mine, and is listed as 12 – 24 volts. as such with no space for thrust movement you are bound to get friction and therefore a drain on your battery power.

i would suggest you move your motor back away from the tube by about 5 mm at least to allow movement created by the motor.

[neil hpParticipant @neilhp]

watch the couplings and see how they move .just click on to the photos until you find the video. this was the boat with rusted shafts.

Facebook

Edited By neil howard-pritchard on 22/08/2022 01:30:19

[matt ChurcherParticipant @mattchurcher85021]

Thankyou. How do I watch the video? I can’t see a link anywhere. I do notice I get a little water and grease coming into the hull where the prop screws in. Is this normal?

[Richard SimpsonModerator @richardsimpson88330]

Click on the word "Facebook" in Neil's post.

Further to what Neil has said I notice that you haven't got an oiling tube on your shaft. If the tube has grease in and you are getting water ingress there is a very good chance the tube is full of solidified grease/muck/rust/water etc..etc.. Particularly if it has been sat there for six years with water in it.

I really think you should remove the motor, coupling and shaft, give everything a thorough clean up, re-oil or grease, I'm not a fan of grease in shafts but with your motor you should get away with it, and reassemble ensuring you have the play that Neil suggests.

Along with Neil I strongly suspect you will find a tight shaft.

Edited By Richard Simpson on 22/08/2022 08:18:15

[ashley needhamParticipant @ashleyneedham69188]

Absolutely With Neil on this, A good dismantling, clean and inspection is always the first thing to do.

Ashley

[matt ChurcherParticipant @mattchurcher85021]

I very much appreciate your help. The shaft was cleaned recently thinking that was the cause of the problem. The water coming up through is worse now though sadly. I click on the Facebook word but just takes me to Facebook and no further.

[Richard SimpsonModerator @richardsimpson88330]

Same here, it says the video is no longer available, sorry! Neil!!

Water coming through is a sign of worn bushes. Do you have either grease or oil in the tube? With your motor you could get away with grease, which will help to seal the bushes better and prevent leakage. You can get new bushes or you might find the leak slows down to an acceptable level with some grease in it.

[ashley needhamParticipant @ashleyneedham69188]

You could make some washers out of a plastic milk carton (or buy some!) and use them either end of the shaft. You can then adjust the play for zero movement to help stop water coming in. Bottom will be water lubricatedand a drip of light oil inboard will keep them happy.

Ashley

[matt ChurcherParticipant @mattchurcher85021]

I like the idea of stopping the water as it does get wet after lots of use. So earlier I was told that the batteries wouldn’t really matter if I kept using 6v instead of half power 12v. Would there be much benefit in getting the 14ah batteries that the component store does

[Richard SimpsonModerator @richardsimpson88330]

Matt, The voltage of the battery dictates the speed at which the motor turns. A 12v battery will turn the motor twice as fast as a 6v battery will so operating your motor on 12v at half throttle or 6v at full throttle should, theoretically give you the same speed.

Current flow is a different thing. The battery holds charge, which is current waiting to flow. Connect it to a motor and the current flows out of the battery. The amount of current that the battery holds will determine how long the motor will run for before the current runs out. It does not determine how fast the motor spins it only determines how long it will spin for. The current required is dictated by how much work the motor is doing. A big motor driving a heavy load uses lots of current so drains the battery quicker.

A 14ah battery is only a measurement of current capacity. It will hold enough charge to supply 14 amps for 1 hour. It would also supply 28 amps for half an hour or 7 amps for 2 hours etc. To really understand your requirements you need to know what current your motor needs, which can only be determined by putting an ammeter in line with the motor when it is running under normal load. i.e. in water. Obviously not always the easiest thing to find out so that leaves experience and trial and error. If you fit a 7ah fully charged battery and run it for an hour at which point the motor dies, conveniently, then you know the motor has drawn 7 amps for that hour. Everything else is proportional. So a 14ah battery will last twice the length of time on the water as a 7ah one would, when running at the same speed.

I hope that helps.

[Colin BishopModerator @colinbishop34627]

Just to add to what Richard has said, lead acid batteries should not be discharged below 50% of their nominal current capacity as otherwise irrevesible damage to the internal plates can occur.so a 14ah battery would have a practical rating of 7ah.

Other types of battery such as NiMH can be run down by almost all their nominal capacity and safely recharged.

Offsetting this is that during a typical model boating session you won't be running the model at full speed all the time and the average current draw will be much less than the draw at full speed depending on the proportion of time you spend with the model stopped or travelling at half speed etc.

Colin

[matt ChurcherParticipant @mattchurcher85021]

So in theory if a 12v battery running at half chat would use the same draw as a 6v on full chat I maybe able to get a bit more speed by using a 12v and setting the throttle just a little fast. The outcome may mean a little extra power drain but a faster boat? The use of the boat varies also. For example when I am sending the boat out it could be carrying a possible 2kg load which would impact speed and amp draw but on the way back when empty this would drop. I know when I put the 6v 10ah batteries in the extra 800g made a difference to speed but I think they are a bad pair. I took a video yesterday of the motor running out the water. The batteries voltage dropped like a stone and sounded like they were flat where as the 6v 7 ah I have kept a constant voltage after it is load.happy to share these videos if anyone is interested lol. I personally would like to have it faster and consider a couple of 12v 14 ah batteries and then adjust the speed controller.
mid I did this would I need to change the speed controller ? It’s a Msonic 15a marine at the moment.

[Colin BishopModerator @colinbishop34627]

Yes, the 10ah batteries sound as if they are clapped out. Initial voltage OK and then suddenly dropping on load is a typical symptom.

As you suggest, if you use a 12 v battery and use the throttle setting to adjust the speed to a anywhere between full speed and 6v speed equivalent then you will reduce the current draw accordingly and can find a happy medium between speed and power consumption. You have the extra speed if you need it but also the option to slow dow and extend running time. That is a lot more flexible than using a 6v battery with inadequate top speed.

The controller absorbs a small amount of power but not enough to worry about.

Whether the 15 amp controller will be adequate depends on how much current the motors draw under load. You can easily test this by measuring the amperage drawn with the boat held in the water with the motors running at full speed which should not exceeed 15 amps. You can also check the amps drawn at various throttle settings which will give you a feel for optimum speed balance between speed and power draw.

Colin

[matt ChurcherParticipant @mattchurcher85021]

Thankyou Colin. I will have to do some trials lol. Luckily my mate has some 12v batteries I can test to see how it goes before buying.
It’s all a learning curve for me. Certainly nothing is straight forward and it’s a weighing up options to get the best out of the bot and the batteries. The boat I have is no longer made and the guy that made it didn’t make many. He did however explore all of the flaws with the boats that were available then which enable him to produce a better all round boat certainly back then! It can handle rough sea if needed and carry at least 2kg bait. I believe he set it up as 6v to made it a work horse with the 850 rather than a speed machine. It would be nice to go a little faster though if only when it’s empty

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