<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>Thanks Steve,</div><div id="AppleMailSignature">that's a great spread sheet. Hopefully I can come up with something</div><div id="AppleMailSignature">as professional as that with my next set up. My results ( which I have temporarily lost)</div><div id="AppleMailSignature">were just Volts in, amps & thrust. This gave me thrust per Watt. They</div><div id="AppleMailSignature">were encouraging enough to keep me going down this track. </div><div id="AppleMailSignature">I ran the Saite motor off 48V from a rectifier that had a limit of 40 amps. </div><div id="AppleMailSignature">I only ran the Saite motor with the 2hp Yamaha prop. </div><div id="AppleMailSignature">Cliff posted a good spread sheet on his tests with different props on</div><div id="AppleMailSignature">the Minn Kotta 101. He was getting quite a varied result in efficiency</div><div id="AppleMailSignature">& thrust.</div><div id="AppleMailSignature">Cheers Alan</div><div id="AppleMailSignature"><br>Sent from my iPad</div><div><br>On 12/03/2018, at 3:11 PM, Stephen Fordyce via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div><div><div><div>Hi Alan,<br></div>Thanks for all that. I'm not oil filling, so that helps with most things, although getting rid of heat is a headache. The (ambient) housing of the DPV is all plastic, so I'm going to have to implement a water cooling system, at least for the prototype. The motor isn't designed for water cooling, so it will be a bit more annoying. Might look at a proper water cooled motor next.<br><br></div>Since I'm retrofitting the motor & controller to the DPV, it's rather nice that I don't have to worry about other variables like modifying the motor. The prop/shaft/seal assembly terminates on the inside with a large gear, so I "just" had to make an adaptor bracket for the motor and a 3D printed shaft coupler.<br><br></div><div>I imagine you're across it, but are you checking on efficiency in your prop experiments? (as in, mechanical power out, over electrical power in). This can be calculated indirectly and it's really interesting to see how badly a motor can be performing despite a high input power. I thought I was doing well with an undersized 70Kv motor apparently rated for 2.8kW until I realised it was only operating at 30% efficiency (80-90% should be quite achieveable). The attached spreadsheet (warts and all) that I made may be of interest. Not sure how it translates to oil-filled - probably ok if you use the figures from before it's filled with oil.<br></div><div><br></div>Cheers,<br></div>Steve<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Mar 12, 2018 at 12:48 PM, Alan via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto"><div>Steve,</div><div id="m_-1898502139693879098AppleMailSignature">some information in case it helps.</div><div id="m_-1898502139693879098AppleMailSignature">you might have heard some of this from me before, but I have been oil filling </div><div id="m_-1898502139693879098AppleMailSignature">the thrusters. I started with the Saite motors but a few things went wrong</div><div id="m_-1898502139693879098AppleMailSignature">that were possibly my fault. </div><div id="m_-1898502139693879098AppleMailSignature"> Firstly I didn't have an oil compensator to create an over-pressure & the</div><div id="m_-1898502139693879098AppleMailSignature">oil was moving up the wiring tube when I started the motor. Possibly the</div><div id="m_-1898502139693879098AppleMailSignature">motor design was creating force that was doing this, or centrifigal</div><div id="m_-1898502139693879098AppleMailSignature">force inside the motor was throwing the oil out.</div><div id="m_-1898502139693879098AppleMailSignature">The oil I was using was degrading the main wire insulations & I suspect</div><div id="m_-1898502139693879098AppleMailSignature">dissolved the glue on the sensor board. They glue the sensor board at Saite</div><div id="m_-1898502139693879098AppleMailSignature">with a glue that can be melted so you can adjust the timing of the motor.</div><div id="m_-1898502139693879098AppleMailSignature"> I suspect the timing went out & it overheated, or it overheated first & </div><div id="m_-1898502139693879098AppleMailSignature">caused the sensor board to come loose. It stopped running after</div><div id="m_-1898502139693879098AppleMailSignature">30 hrs. </div><div id="m_-1898502139693879098AppleMailSignature"> I had replaced the propellor shaft with a 316 shaft that I turned down so that I had</div><div id="m_-1898502139693879098AppleMailSignature">12mm to fit the prop & 8mm through the motor. I didn't pay enough attention</div><div id="m_-1898502139693879098AppleMailSignature">to getting the press fit right. The whole bell is attached at that one press fit</div><div id="m_-1898502139693879098AppleMailSignature">point. I think I should have heated up the bell a bit & frozen the shaft & </div><div id="m_-1898502139693879098AppleMailSignature">pressed it in a press, however would need to be weary of splitting the aluminium. </div><div id="m_-1898502139693879098AppleMailSignature">The result of the not so tight fit was the bell moving off centre in time, this seemed </div><div id="m_-1898502139693879098AppleMailSignature">ok when running at speed but would scrape at slow speeds. I had looked around</div><div id="m_-1898502139693879098AppleMailSignature">for a suitable motor with a can bearings like the Turnigy 6374 but not sure if</div><div id="m_-1898502139693879098AppleMailSignature">this is necessary. </div><div id="m_-1898502139693879098AppleMailSignature"> Tested it out with a 2hp yamaha prop & was getting as good as or better thrust</div><div id="m_-1898502139693879098AppleMailSignature">than the average thruster that I had information on was achieving. Have a number</div><div id="m_-1898502139693879098AppleMailSignature">of props to try out. </div><div id="m_-1898502139693879098AppleMailSignature"> Next step is to build another thruster housing for the Maytech motor, make a new </div><div id="m_-1898502139693879098AppleMailSignature">test jig & order a plc to control the tests. </div><div id="m_-1898502139693879098AppleMailSignature"> One reservation about the Maytech motor is I may have to drill angled holes </div><div id="m_-1898502139693879098AppleMailSignature">in the end of the bell to cause an oil flow across the windings, or add a small</div><div id="m_-1898502139693879098AppleMailSignature">impeller to do the same.</div><div id="m_-1898502139693879098AppleMailSignature">Are you oil filling? </div><span class=""><div id="m_-1898502139693879098AppleMailSignature">Cheers Alan</div><div id="m_-1898502139693879098AppleMailSignature"><br></div><div id="m_-1898502139693879098AppleMailSignature"><br>Sent from my iPad</div></span><div><div class="h5"><div><br>On 12/03/2018, at 1:36 PM, Stephen Fordyce via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.<wbr>org</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div><div><div><div>Hi Alan,<br></div>Hah! That's the same motor that I ordered - should have checked with you first (1 @ 60Kv and another at 70Kv).<br><br></div>Yes I'm a big fan of the temperature sensing, and the sensors are nice for FOC control (quieter at slow speeds).<br><br></div>Cheers,<br></div>Steve<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Mar 11, 2018 at 3:32 PM, Alan via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.<wbr>org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto"><div>Thanks Steve,</div><div>any information on them is helpful.</div><div>Perhaps Maytech are putting out the Vesc with heatsink as a result of problems!</div><div>Not sure if this instigram link works but it is a preview of the Vesc...</div><div><a href="https://instagram.com/p/Bd2GOBLA1rU/" target="_blank">https://instagram.com/p/Bd2GOB<wbr>LA1rU/</a></div><div>I bought 6 x 6374 sealed sensored outrunner motors off Maytech that I had them wind to 60kv.</div><div>They have a temperature sensor on the hall sensor board that the Vesc reads, which</div><div>will be handy for testing. Am running these in oil.</div><div>They are using these motors on electric surfboards. The wiring isn't as stiff as the "Saite"</div><div>motors I tried. </div><span><div>Cheers Alan</div><div><br></div><div><br><br><div>Sent from my iPad</div></div></span><div><div class="m_-1898502139693879098h5"><div><br>On 11/03/2018, at 12:48 PM, Stephen Fordyce via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.o<wbr>rg</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="ltr"><div><div><div>Hi Alan,<br></div>Yes I looked at the Maytech VESC builds (and have also ordered a BLDC motor sample from them), but the e-skaters do have a few negative things to say about it. I've been testing a "E-SK8" version I got from Hobbyking and it's been completely fine, but the FOCBox has all round excellent reviews and looks the part - I'd rather pay a bit more for something so critical (and I want to be able to use FOC control too). Since I'll be on-selling, hopefully I can get much better than list pricing - I'll let you know if I'm doing a bulk order.<br><br></div>Cheers,<br></div>Steve<br><div><div><br><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Mar 10, 2018 at 1:37 PM, Alan via Personal_Submersibles <span dir="ltr"><<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.o<wbr>rg</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto"><div>Steve,</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">thanks thats good to hear. </div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">I bought my Vesc from Maytech in China. They sell them along with a remote</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">controller for skateboard use. They look like they have done a good job, &</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">if they haven't you'll hear about it from the Skateboarding community.</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">My Vesc cost about $100- & they are about to release a Vesc with heat sink</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">in an aluminium housing.</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">The Vesc Maytech sent me needed the firmware updating, & then I had to order</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">an ST link from them to update the firmware. They sent the wrong wires with it.</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">Apart from that, I have been buying bldc motors from them that are good quality.</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">Will let you know when they release this & what the price is if you like.</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">I was looking at the focbox, it looks like they have done a good job with it.</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature">Cheers Alan</div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature"><br></div><div id="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880AppleMailSignature"><br>Sent from my iPad</div><div><div class="m_-1898502139693879098m_-2661755419595918824h5"><div><br>On 10/03/2018, at 10:04 AM, Stephen Fordyce via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.o<wbr>rg</a>> wrote:<br><br></div><blockquote type="cite"><div><div dir="auto">Hi Alan,<div dir="auto">I've also been using the VESC brushless motor controller (I use the FOCBOX type, which is sold in Australia) for diver propulsion vehicles and they are fantastic, with all their diagnostics and open source firmware. They also can have a Bluetooth module added so everything can be monitored on a smartphone app (Android).</div><div dir="auto"><br></div><div dir="auto">Cheers,</div><div dir="auto">Steve</div></div><div class="gmail_extra"><br><div class="gmail_quote">On 10 Mar 2018 6:23 am, "Alan via Personal_Submersibles" <<a href="mailto:personal_submersibles@psubs.org" target="_blank">personal_submersibles@psubs.o<wbr>rg</a>> wrote:<br type="attribution"><blockquote class="m_-1898502139693879098m_-2661755419595918824m_8982106852155081880quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Cliff, Steve, (mainly)<br>
just an update on where I am with the plc choice.<br>
Even though I had done a plc programming course I was getting totally<br>
bewildered with all the I/Os & what sort of information I could extract<br>
from my motor controller, BMS etc. Have bought a Vesc which is a small electronic<br>
brushless speed controller that can read rpm, amp draw & temperature from my<br>
motors. I have over 60 I/Os & most are analogue.<br>
I ended up contacting an electrician specialising in industrial automation<br>
who is also an electronics geek. He is young enough to be up on all the latest<br>
technology. He is coming up with all sorts of ways of reducing the I/Os using<br>
raspberry pi etc.<br>
So glad to leave it in his hands; will see what he comes up with.<br>
Alan<br>
<br>
Sent from my iPad<br>
<br>
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