The disc brake doesn’t matter, what we need is the torque that it generates, so the load cell matters, but that can be easily calibrated using a portable dynamometer, the ones used to tighten bolts
Would you mind to share the excel data for the competitors to you and not yours? It’s not critical to my development but would be nice to have.
This is a community driven process. We’ll have some form of database I think.
Heads up, I have created the thread regarding Dynamometer to properly split the topic. Look for it under innovations.
Is the stator on your website the same one that’s in your motor or is that just a dummy stator with unrealistic pole count and such you used to camouflage your design?
We’ll share studies on all we tested, including ours, in the near future.
The stator is our actual one. Check out the Mellow subforum here, or the MellowBoards subreddit on Reddit for more.
What is the steady state temp of your motor cover / hanger?
guys, kudos for this thread
In my opinion this is one of the most informative, valuable and civilized discussions on this forum.
Respect
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It’s a study of science by engineers and design practitioners. With any luck, we can pioneer something great.
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Progress Update
This is how a hub motor should behave. It’s only taken a few months of simulation to get here. With a 4WD setup, less heat is generated per motor when starting so the temperatures tend to stay pretty cool. Practically, the thermal results indicate you wouldn’t want to push more than 1.5 hours of riding time and definitely half that if you’re going up hills constantly. Two motors aren’t strong enough and wouldn’t stay cool under those conditions with 100kg of human… Looking at the data, I wonder how close these results are to the specs from the Action Blink Quatro.
Easy to replace stators/inexpensive recycling or rewinding would be a victory.
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And what about a forced air cooling? I think going 4wd is a major drawback that most people, incluindo me, would not do But sure that flat torque curve is pleasing
The loses are linear with torque? Maybe you could could run the simulation with 1/2 and 1/4 of the current just tô see what we get, in the average course you would never be using full torque constantly
I noticed that the torque versus grade that you are using are significantly higher than what I calculated(80mm wheels 90kg person and taking in account aerodynamic drag)
Edit: did you used the diameter of the wheel on your spreadsheet? It should be the radius, if I divide your results by 2 they agree with what I found
Isn’t it that the cooling effect get’s stronger the higher the temperatur difference is between the motor and the air. Because it seems that this isn’t taken into account in your graph.
@Pedrodemio, I want the motor to achieve kick ass at 75%, not 100%. This is going to make the motor survive for longer and perform better. More head room.
@Ackmaniac, It is, but I can’t calculate forced air Coolings efficiency for something this small. It would have to be measured, not calculated then included in the simulation. I do not know how well ventilated my rotor will be since I am still playing with cap designs. I am limited by the 5Axis CNC mills I can use. An impeller seems like the best idea, but idk if it would survive 100kg hitting a crack at 30mph. Solidworks syas it would, but it assumes perfect quality aluminum. Titanium is too expensive and hard to mill right now, so I’ll look into that later.
Digging this old thread
@anon94428844 it’s been a while since you logged here, but what end become your hub?
For anyone wanting to play. Infolytica was bought by Siemens recently and now the MotorSolve online trial is much more powerfull, with the thermal module included and lasts for 15 days
https://www.mentor.com/products/product-eval/motosolve-cloud-base-trial?sfm=free_form