Ok, let’s assume that the drag is negglible.
Then I will wait to hear is there any wobbling there when rocking the motor up and down. If there any wobbling, two motor screws could be made longer and hold the pieces together instead of the M6…
What were your considerations when you made that diagonal cut between the parts, instead of flat?
The flange nut reminded me to mention my experience that m4 bolt and m4 nut under hefty tightening sink into the tpu, so I used washers. Flange nut is a great idea!
Found also these nice things:
Now on my 4th battery build for this setup, this time with salvage 35E that were all capacity tested OK.
Hope it keeps balance better than the other 30Q packs
The holes could also be filled and shaped to match the contour of the shell with moldable EVA foam. This foam can easily and non-destructively be pulled out to access the bolt. Then pack and shape a new foam insert when reinstalling again.
Print was a failure after 8 hours of print, trying another method now in two parts and integrating a cutaway piece to act as support.
Edit, changed again to ease printing
I had lots of print failures trying to get this flex mount to work, but not giving up yet.
Finished and potted the 35E pack.
That is such a compact and smart looking battery build. Perfect form for what is needed.
What are you using for potting?
Epoxy/casting epoxy
Works well for me, but probably not great for bigger batteries
I wonder if balance issue you experienced could be the casting expoxy eliminates room for mechanical expansion of the cells and/or may be thermally too insulative.
Probably the 30q samsung cells. They continuously die on the lift batteries just like that.
@gazlinux I don’t think so, I agree with @Jezza , something very wrong with 30Q cells, they are not stable at all. I used 20K of them for batteries we built at work, and despite good bms and cell matching they develop self discharge when they heat up.
My experience with 35E is the complete opposite, very stable cells.
The 35E pack I made clearly has less power, but I still managed to start without any issues on my 4"2 board. will be more challenging the choppy water and low battery. With the 7"2 board, it should not be an issue.
Did not push it as I forgot the TPU and did not want to risk loosing the whole pod and prop!
Dock situation is improving for pure pump, we still have 16 more cubes to add.
Dock :
The GY mast with 1201 is really starting to limit me, it has quite a lot of drag at higher speeds. With the 1201, the cruising pump speed is > 16km/h
@nekitesurfing Did you test the other masts we were talking about yet?
my friend has a One mast, it seems very rigid and nice, but 1000€ is hard for me to justify for a single piece of gear!!
It hasn’t arrived yet but has been posted so should be with me in the next 2 weeks.
The one mast does look good. One thing to note though. I saw someone who had quite bad (and quick) wear with there aluminium fuselage using that mast. The thoughts were that it didn’t have an epoxy / glass barrier between the carbon and the aluminium so led to galvanic reaction. This could be sorted easily enough though.
I wanted to ask if you’ve had any issues with the batteries after embedding them in resin. All lithium-ion batteries need some space as they emit gas, especially when discharged quickly. There’s a risk that this gas could accumulate and cause problems. Have you noticed anything unusual over time?
Well, cylindrical cells are not the same as pouch, I have not enough feedback to really tell, only a few months and a few batteries built with old salvaged cells.
Cells should not vent unless abused or faulty from my experience.
Well they should not release unless something is wrong.
If you have a fully sealed waterproof pack and no gore tex type of vent, you will have similar issues, at pack level rather than cell level.
Some companies have been making this style of packs for a few years, not sure about the failure rate, but here is a torture test :
PU rather than epoxy
FD fully pot the Molicel P42a’s and now the P50s in epoxy and with the amount of batteries in use globally without issues it was good enough for me to pot my cells.
Do you know what they do for bms?
Is it also potted?
That would be interesting to know!
