seized 3060\6 lehner

[carlton jacobs]

I've seized my brand new lehner 3060/6 there looks to be what looks like fragments off a broken magnet when you look into the back its away awaiting the report from lehner.I reset the switches on my shulze 40.333 for a soft start no reverse waited for the correct beeps then moved the throttle stick forward 5 mm max there was a 2 second pause then the motor revved and seezed in 1.5 seconds.The motor had no load and I've re checked the esc settings have i made a stupid error or is there a fault somewhere,has anyone got any ideas.Set up shulze 40.333 esc and 5000mha 12s21p The motor has been run slowly twice with the forward and reverse setting for a few second without problem.

[photohoward1]

Originally Posted by carlton jacobs

I've seized my brand new lehner 3060/6 there looks to be what looks like fragments off a broken magnet when you look into the back its away awaiting the report from lehner.I reset the switches on my shulze 40.333 for a soft start no reverse waited for the correct beeps then moved the throttle stick forward 5 mm max there was a 2 second pause then the motor revved and seezed in 1.5 seconds.The motor had no load and I've re checked the esc settings have i made a stupid error or is there a fault somewhere,has anyone got any ideas.Set up shulze 40.333 esc and 5000mha 12s21p The motor has been run slowly twice with the forward and reverse setting for a few second without problem.

Assuming you did nothing stupid...They will take care of it. They are good about that. Could just be a bad rotor. A 3060/6 on 12s though? 1167 per volt. Even rating the cells at 3.5v per cell is almost 50k rpm. way to high for that turn of a motor. Unless you are wiring it in the star configuration for lower RPM.

[JfromJAGs]

Carlton, I'm sorry to tell you, but you did indeed something stupid: you ran that motor at about 65.000 RPM and that made the magnets explode.

You ran a 3060/6 on 12s LiPos. From the given load RPM of 1167 U/V the free running RPM (KV) can be estimated to about 1300 U/V (add about 10%). You ran that motor on 12s * 4.2V = 50.4V - lets assume only 50V - multiplied by 1300 U/V, this is approx. 65.000 RPM.

According to the instructions (click here) the 30 series motor got a mechanical RPM limit of about 50.000 RPM.

=> so your idle RPM was too high and thus the magnets disintegrated. Your setup is right on the RPM edge under load (where the battery voltage drops and also the load RPM of the motor is lower), but whenever your motor spins unloaded, then it will spit magnets.

Honestly, Carton, I follow your experiments for a while now, your pulse jet tests and also later your successes with the rocket motors. I admire your persistence in following your ideas and dreams, honestly.

I then read you were trying electric drives as the next step and I got a bit afraid when you were asking how to wire the 12s2p LiPos. I don't know how to say this without sounding like an arrogant prick, but I think you are approaching this project from the completely wrong side.

1. It doesn't take that much power to break the existing record. 6s to 8s (1p) should do the job. Most likely even easier than with a huge and heavy boat.

2. So far you don't seam to have much experience with electrics drive systems, with electric motors, with ESC or with LiPo batteries - your questions indicate this. So as a first FE project, starting with pretty much the biggest FE motor available, the biggest ESC available and a huge number of LiPo cells is not only pretty expensive, its not the preferred beginners project, as there is simply so much learn about the technology first.

3. Looking at the design of your boats I assume you have a tether boat background. I don't know how much experience you got with freely running propeller driven boats, outrigger in particular, but also here, there is a lot to learn about boat design, boat setup and especially propellers. Things that are significantly different to tether boats.

I don't want to take any of your courage or dreams away, but you should definitely start with something smaller, maybe 3s to 4s (1p). Learn how to understand electric drives, electric motors, ESC, batteries. Learn more about outrigger design and setup for propeller driven boats and about propellers too.

Most likely you will burn up and/or loose equipment - everyone did this so far - everyone has paid his fair share - but starting smaller it won't cost you $5000 every time.

You know, there is this old and wise advise: learn how to walk before you want to run. There is quite some truth in there.

Joerg

[carlton jacobs]

Thanks guys jorg I've taken onboard what you have said and you are right but at the end off the day modelling for me is all about having fun and i don't take any of it to seriously my videos and boats are for my enjoyment and if people like to watch thats up to them i don't pretend to no what I'm doing thats why I've asked you guys who do, my rocket boat and pulse jet is the only boats I've ever built I'm not from a boating background there built from scratch using my ideas the electric boat is no different and it properly won't work but what the hell does anyone really care its going to be good fun trying.Thanks jorg for your answer now i no.

[JfromJAGs]

I'm not sure if there are any SAW activities in the UK at the moment, but I know there will be a bunch of people as "crazy" as you (and me) at the 2nd International SAW on the Regattabahn in Duisburg, Germany from 10-12 August.

Joerg

[graill]

Originally Posted by carlton jacobs

Thanks guys jorg I've taken onboard what you have said and you are right but at the end off the day modelling for me is all about having fun and i don't take any of it to seriously my videos and boats are for my enjoyment and if people like to watch thats up to them i don't pretend to no what I'm doing thats why I've asked you guys who do, my rocket boat and pulse jet is the only boats I've ever built I'm not from a boating background there built from scratch using my ideas the electric boat is no different and it properly won't work but what the hell does anyone really care its going to be good fun trying.Thanks jorg for your answer now i no.

i recall in December 2003 joerg and a couple others playing email ping pong explaining things to me as i was transitioning up to the very big motors, and their limitations, not only was cost a factor but joerg told me the math has to add up, i have always used this advice.

I like your fun spirit carlton and your vids are indeed fun to watch, still when you start blowing 1 grand a run or taking that income and blowing it as "experimental" i do not see the fun in that, unless you are filthy stinking rich

I spent two years plus on research and prying into folks in mmainly germany and switz about the big lehners and learned a ton, mainly playing at that level is expensive and if you do not know what you are doing it will cost you, they are all good teachers, dont be discouraged and certainly do not discount advice because you may not want it or think you do not need it, everyone has something to learn whether they believe so or not, regardless of the time they have been in the hobby.

Looking forward to seeing your projects. My bit of advice, rev limiters, radio programming to restrict throttle and use the timing settings on your esc just for starters besides the advice Joerg gave. And above all, learn basic electrical theory and DC/AC motor theory. the more you understand the easier the hobby will be and the more things you can experiment with without causing destruction of your property or killing someone or yourself.