The Awithz are very popular welders and don’t require an extra battery for operation, check out DIY500 on YouTube. Molicel are reliable, but so are the Samsungs. If I’d chose a welder this day it would be the Awithz (there’s multiple) as you do not need an extra battery for the welder itself which I hate.
The Kweld is still a good welder, but it was one of the first “proper” welders. In the meantime more options have become available. Don’t get me wrong, but the Kweld is already 8-9 years old. It’s still very effective and I have used it twice now for some packs.
Have you had a chance to compare kWELD to Awithz then?
I have the impression most spot welders have very thin, needle-like electrodes, which makes them work better with less current / worse power supplies, but also in my experience makes for welds that are less strong or higher resistance…
Not directly. I have watched quite some reviews and videos. DIY500 has a bunch of them. He’s one of the most known YouTube diy pack builders with his own shop. The larger Awithz models can weld 0.3mm copper, and the electrodes can be changed on most welders. But I get your point, and I am familiar with cheap tiny electrode welders which are not effective, the awithz ones on the other hand are much different and more powerful.
Bom dia folks I was doing a little thinking about redundancy options for the board last night blame @ludwig_bre haha and I got to thinking about a twin system giving a limp home option if one system gives up. After a bit of research I can see it has definitely been done so I got to think about how I would accomplish it.
which leads me to my first question can you run 2 systems from one remote system?
Obviously cause the twin battery pack now becomes a single 2kwh for each system how will this affect my range? Clearly there will be more drag from the twin motor but on the flip side the motors should not work as hard because they are working together meaning less consumption per motor. Is there a more efficient motor I should consider which will still have enough power for single operation?
Thinking about the mountng I like idea of making a custom Fuselage which the motors mount either side and the stab is relocated deeper in the water to avoid disturbed water. Another option could be to have one motor in the normal location and create a dagger board under the mast for the second motor this would stop the pull to oneside if a motor stops. whats your guys thoughts on this go big or go home idea😆https://s.alicdn.com/@sc04/kf/Hc9c3dca2d9c448a8893ac7cde642475fT.jpg_640x640.jpg
I would however keep complexity low
I only recommended 2nd VESC because it adds almost 0 complexity
Adding a 2nd motor will add complexity in choice, mounting, cable routing,…
While I definitely see the appeal, it may be overkill for the first prototype?
Having the motor break completely is unlikely, you may break a bearing but can limp home with that… a broken VESC won’t limp
Breaking a propeller is also likely, so take a spare of that for the singular motor.
For your weight/setup you should use 65161 or bigger, to ride on it as a single motor imo. It is quite efficient too, just long and heavy.
That’s possible with multiple simple ways to choose
Not at all Sir. I am glad you got me thinking about it most of mad things I have done in my life always have a Plan A, Plan B and Plan C. Only on very few occasions have I made it to C tho. The original plan (A) if the system goes down its swim ashore or pan pan its straight to plan C. Twin motor gives me Plan B without having to be dependent on others. If the remote is just giving signals I really shouldn’t need to do anything just limp home. Multiple times members have brought up mast flex and looking at builds people are chopping there masts to make room for the motor weakening the structural strength of the mast. Taking a Fuselage and Tig welding some Alu pipe vertically and half pipe mounts for motors seems more logical to me. I also plotted the trip I want to be able to accomplish round Cape St. Vincent and its 26 nautical miles total and catching it with right tide I am thinking could be possible on a twin 2kwh system. So let me know your folks thoughts.
Top of the morning to ya. Doing some more research last night I think using a Fuselage extension piece from gong and adding custom motor mounts with Alu pipe. One above the Fuselage and one below with the bottom one I will attach a Alu long board fin to avoid sea bed collisions with the prop. Also will get my friend to 3d printed 2 nose cones for the front of the motors. The beauty of doing it this way is the mast, front wing and stab should all remain original meaning I can switch and sell them on no problem if i want. My optimal target is December but more than likely January or February. So far the battery spot welder, Tig welder and hot string are ordered. I will build it in my evenings after work and I hope I hit December but we all know how that time of year goes plus I need to avoid getting murdered by the misses for spending a chunk of wonga on a crazy project
Some recommendations from my side:
Mast lengths: I have several diy foils with aluminium masts between 65 and 95cm - for chopy conditions I find the 85cm the best compromise.
95cm is too long: Difficult to get on foil and quite flexible.
Battery: I basically use different batteries for all my builds.
Worst experience I had with the original Samsung 18650 which showed significant drift even after the first year - but even after 6 years they are still useable.
My favored battery so far are the LG M50LT cells - cheap, plenty of capacity and no drift even after 3 years - same cell I have in my Tesla
However, for my next build I will use a higher capacity version from LG, Lishen or EVE. In my experience with an 8p or larger battery everything above 10A discharge is ok.
If long range is your priority I would go with the new Molicell or EVE 6Ah 21700 batteries.
Otherwise I would recommend to trust ludwig_bre - he has lots of experience and is always reliable in his advice!
How high is the motor normally placed above the front wing the diameter of the prop is 153mm?
How is everyone dealing with foil mounting having fish bones for foil adjustment would be nice but then how do you deal with cable slack if I have used epoxy to seal the cables to board?
I place it as low as possible, maybe 5 to 10mm gap to the fuselage
My motor cables are sealed with silicone on the top of the mast towards the mounting plate
No slack really, just enough to exchange the motor mount adapter
What you mean it don’t come with a 10 year Ludwig guarantee lol
That link ain’t working for me.
I heard someone call them fish bones but I think there actually called rail mounts or box would be nice to have mast adjustment but it creates an issue with cable slack. Didn’t know people still used silicone haha get yourself some sika flex or epoxy for a proper seal.
Looks like just a relay and a normal off the shelf pull cord kill switch
Should work with any receiver and ESC
From what I see it will steal 5V from the Rx for relay power
And with the relay forward or short-circuit the PWM signal used for communication between Rx and ESC
For your build all I can say for maximum reliability keep it simple. The best part is no part. Single oil filled motor, aluminium prop, over spec the vesc (like a makerX g300) with passive cooling, carry a spare remote.
For extra reliability a direct discharge battery is probably better, but via a BMS is quite reliable if the pack is made well, no bad welds which could cause shut down protection.
Most issue people have are with water getting into the system so spend 90% of the design effort make redundancies around that. Corrosion X and potting.
Thanks for your insight. I Agree with keeping it simple theres a reason the Ak47 is the most common gun in the world simplicity and reliability. Currently trying to get some board inspiration and design the shape is there a software anyone recommends? I like the idea of the board having a dugout with a point nose/raised wave breaker nose a flat deck at the stern and a gunwale. Some images I like and yes I understand some are paddle boards and are far too long I am purely look at shape
Its no cad drawing but it works. Getting pretty close with side profile I want. The board will have double thickness on the flared nose and a small gunwale on the deck with an open stern considering placing one battery pack behind the mast for better balance.
