Roadster E-Board Build (videos added 15/06/14)

made_in_the_alps_legacy said:
Forget about Heli ESC unless you want to go brakeless,
made_in_the_alps_legacy said:
So... how are you going to brake now? :pancake: :pancake:
Dave, sorry if I wasn't explicit enought. those esc do have a brake (you will be able to turn it ON/OFF with the program card, no other choices)
My worry for you is that this brake is aimed to stop a few grams propeller in a fraction of a second, ... are you a "few grams" propeller ? :mrgreen:
can they be reprogrammed for different levels of braking force ?
EDIT : I did play around with the function, but it won't help with respect to the matter above... what I know is that my e-secooter motor runs hot on this esc and had to reglue loose magnet - with no luck actually - but this might be a quality issue of the motor (the same one as yeti got without the rotation locking pin...)
 
Fair enough, I did expect the braking to be nothing like a car/boat ESC. If it's completely impractical then I'll just have to go back to my original search and find a different one :)

What brand was your motor? I hope my SK3 stands up to the abuse! So far I haven't noticed it getting even warm on 6s.
 
This is how i made my brakes. I need those because heli esc doesn't really brake like you would want. CNCed it frow 5mm thick aluminum plate. Those are standard bike rubbers. I'm using it with bike brake handle but it can also be made with a servo motor :-D

P_20140404_180244.jpg
 
galp - that's a neat simple solution. How well does it work? Was it easy to make?

So in my quest to find a cheap and simple charging solution, the idea I have in mind requires me to bridge 3 connections when the board is in use (two between batteries and one to complete the circuit).

One obvious method would be to use three XT60/90 connectors. I am not entirely against this idea but it does involve a bit more messing around every time I want to charge the board. If I could incorporate all 6
pins into one connector then that would be ideal. I haven't been able to find a 6pin connenctor which can handle the required current so I came up with this idea using 5.5mm bullet connectors:

FHmXySL.png


There are a couple of problems though, the tightness of the fit on bullet connectors would make this quite hard to plug in and out. Also, it would require some fairly accurate fabrication to get the alignment of the pins right.

> Is there any danger in jumping all 6 pins at once? Would connecting them with seperate plugs be safer?
> Are there any pre-made connector types which can handle this level of current?

Thoughts?
 
It's always a good idea to have mechanical brakes not only electric. What if your esc fails when going downhill?

For those connectors, i have them too. Just press them with pliers a bit and they will be easier to plug.
 
galp said:
It's always a good idea to have mechanical brakes not only electric. What if your esc fails when going downhill?
Amen.
 
Cool build

I solved my braking problems with this band brake servo combination

the setup is detailed in http://endless-sphere.com/forums/viewtopic.php?f=35&t=58504 cheap, easy to machine rotor, easy to make and well holder and easy to build.
Work spectacularly well in the correct direction and not at all if placed in the opposite direction of rotation..
 

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Thanks beto-pty, I'll keep that in mind if I decide to add mechanical brakes :)

I took the board out for a little spin but ended up having to walk back 2 miles because I forgot to charge my batteries! Nevertheless, the board was great fun and if anyone is looking for a 6s ESC, I can recommend the Toro 150A.

So I've sorted out the wiring now (I think) and should be able to charge/ride without removing anything. The 3 x 3s batteries will be charged in parallel whilst in situ.

I have made a little panel mount for the plugs. It's messy and I'll probably re-make it for the final housing but while I ride the board for reliability testing it will do. The panel has 4 x XT60 connectors and 1 x 3s JST balance plug:

KGEQXH9.jpg


These connections are bridged with three XT60 'loop keys'. Each plug breaks/connects the circuit after each 3s pack. When they are plugged in, the circuit is complete and the board is ready to ride:

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When charging, the three plugs above are removed, taking the batteries out of series. The pos/neg from the charger is connected to the fourth XT60 connector and they are now connected in parallel. Plug in the balance lead and they are ready to charge. The charger will see them as a 24Ah 3s battery (3 x 8Ah 3s):

KwGC8Hm.jpg


This is the wiring which will live inside the housing. It makes my cry looking at this, I have to have had my coffee before I even think about trying to remember which bit plugs into what :| :

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It's definitely not an elegant solution but I shouldn't need to remove my batteries to charge them and I don't need to buy an expensive charger. Let's hope my soldering is up to scratch, we'll find out at the weekend when I test it again.
 
I wonder: Does the balance plug even have any effect if it is connected to the batteries like that? I have read on some HK reviews of 'balancer Adapters' that do something similar, that it wont really balance since it can not measure single cells.

Aside from that: Nothing wrong with a little brain training before riding, this actually makes it a brain and body training device!
 
furp said:
I wonder: Does the balance plug even have any effect if it is connected to the batteries like that? I have read on some HK reviews of 'balancer Adapters' that do something similar, that it wont really balance since it can not measure single cells.

Aside from that: Nothing wrong with a little brain training before riding, this actually makes it a brain and body training device!
I use the same system. 3 batteries (8s each) and when charging, I put the 3 balance leads in parallel.
You won't measure separate cells, in my case I measure 3 cells together for each little wire. For charging, this is fine. Only when 1 cell is dying, you can't see that from the balance lead. However, you'll notice when you plug them together and you won't like it. That is why I always measure all cells of all batteries before plugging them in parallel. Also, after charging, I measure them again to see if they're balanced.

Works fine!
 
Now that I read it, it sounds reasonable to me as well ;) But cant go wrong with measuring each cell every now and then.
 
Nice build!

I would use a different connectors for charging the batteries so i don't accidentally plug the key in the chargeing port and short the batteries.

Btw it looks like you are using electrical tape for protection. I recently learned about liquid electrical tape and it makes a nicer and neater looking protection. It comes with a Baruch and you just brush it on and wait for it to dry. (Fairly quick). If you ever need to change it just peel it off it like rubber.
 
Yeah eventually I will have different a different connector for the charging port, I'll probably remake the entire thing to be honest for the final housing. I haven't even had chance to see if it will charge/run at all with my new ESC/extra battery! :lol:

Yeah I ran out of heat-shrink half way through and it wouldn't fit on some parts anyway. That looks like a decent product, I wonder what the insulation rating is like? It would be pretty handy for my T junctions which can't be covered with normal heat-shrink tubing.
 
Disaster has struck!

Took the board out for another test ride yesterday and disaster struck! Everything was going fine until I rode over a cobbled speed bump. A wheel fell off!

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More accurately, the weld which holds the split rims onto the central bearing housing failed. Fortunately I wasn't going very fast and I managed to stay on my feet. It's a bit of a gutting problem though, I had been pretty confident that these wheels were a good solution :( I have recommended them to a few people on this forum, needless to say I take it back!

Another problem I was having was that the board didn't want to turn to the left as easily as it turned to the right. I had assumed that this was due to imperfections in the wheels. By chance I noticed that the entire rear truck was at an angle:

2epvY5Y.jpg


Looks like the truck mounting holes have been drilled at an angle in the factory :? Serves me right for buying a no-brand deck!

It won't be too much of a problem to re-drill the holes, more of an annoyance. The big problem is finding replacement wheels :? I might try out the Onda wheels, made_in_the_alps seems to really like them. I want to keep the large diameter and I also want to keep my MBS trucks, the wide wheelbase makes the board really stable.

Any ideas?

EDIT: Should also mention that I don't really want to use standard mountain board wheels because they are too wide and it would mean redesigning my mount
 
The ABS battery covers which I received last week from ADS look great, the material is nice and strong and they look very professional. The covers are designed to sit on a flat deck, unfortunately my deck is concave (convex on the underside). I want to attach the covers with magnets so it needs to fit fairly flush onto the deck, I decided that I would heat the covers gently in the oven and press them onto the deck around the batteries so they would mould to the shape of the deck. This was the result:

wr4tGzv.jpg


:cry: It turns out the ABS becomes malleable at much lower temperatures than I was expecting! Sorry for ruining your lovely work Richard! I tried to salvage the cover but it was too late, it's too far out of its original shape now, I think it may have shrunk slightly too :( I guess I will be ordering another! How do you think I should best get the covers to fit?

On a brighter note, my new wheels from Onda arrived:

L1k2Bw6.jpg


I also bought some Bear ABEC7 bearings for 10mm axles so I'm looking forward to getting the motor pulley modified and fitted to one of the new wheels and seeing how they perform :D
 
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