This is a build thread of my latest board. I call it Rat . I thought I might share it with you all.
Story
My first eskate below was a lot of fun. It was not perfect but it sure put a smile on my face. Sadly it’s parts gave up on me many times.
Last year I built something else. This board is super sweet although it is far from practical. I can’t carry it with one hand, doesn’t turn quick enough and it is a pain to carry up/down my 3 floors.
So that is why I had to build Rat
Rat is a board made by old dirty stuff mostly (hence the name)… yes I don’t think I bought anything for this build . It will look dirty, because it will be dirty. Snails and land dust does that to a board.
Goals…
Comfortable
Carry-able
NO noise, NO rattling
Cheap (I really don’t care too much about the cosmetics… I don’t even plan to paint it)
Parts…
Deck: DIY…I have no idea what kind of deck this is/ was… My colleagues son gave it to me for free
Enclosure: DIY Fiberglass
Battery: DIY 6S1P 15Ah
ECSs: Mini FOC+
Motors: SK3 6354 260kv
Hardware: Trucks, mounts and Pulleys… An entry kit bought from Dork Boards many years ago
Wheels: Rock hard 83mm ABEC clones (with glued tire strips from my friends passed away grand fathers bicyle) Don’t miss this!
Building process…
The deck was too long and I needed a shorter wheelbase to be able to make quick turns.
Forgot to take pics but here is how it looks now after I cut the nose 1dm.
I made the fiberglass enclosure for my old board and now it does not fit the deck. It had to be shortened
Chop!
I cut off a segment from the enclosure and reattached the end piece. (yeah I like reusing things)
Okay, now the length is ok but the there is a huge gap since the new deck is not flat
I modelled and 3D printed some pieces to get the correct shape
Some epoxy work to get the pieces to stick.
Fused XT30 for charging and XT90s will be used for antispark
The battery is 6S1P 15Ah pouch cells.
The tabs are screwed together in series using these metal bands with holes in them. My collection of nuts and screws from old PC builds came in handy. (I did my first battery like this but with rivets instead of screws. It became a shit show with tabs loosing connection after about 500km )
Then I kind of wrapped it into this foam material for protection.
I didn’t plan to use a BMS. Instead I was thinking of using one of those lipo warners for monitoring. However due to its design and the low tolerance resistors, the voltage readings was too much off to make sense. I did try to Macgyver it to something better with other resistors I had at hand but the reading was still shitty on the last cell. A for effort at least
For ESCs I have my two Mini Foc+ from the old build. They have proven reliable to me. However, since I want around 2kW out from my 6S battery, these escs need to take ~50 battery amps each. I beefed up the DC traces with some solder… Just in case.
I used bullets instead of XT90/60 since it allows me to more easy route the cables inside the enclosure
3D Printed a little piece to prevent the two esc from flying around.
From my last board, my SK3 motors were suffering due to the open can design.
They were cleaned up and I gave them an epoxy shield and new bearings. (I remember one motor dying shortly after this. Had to replace that one)
MT60 on the motor phases.
I wanted to get the enclosure as dust proof as possible, therefore routing the phase wires through the enclosure.
while having a good seal, I also wanted to be able to pull the MT60 through the enclosure in case of maintenance. I came up with these printed pieces and some screws to achieve this.
Yeah this does not look good (but it works at the moment). I will have to print something more reliable to prevent phases shorting against the motor can.
Alright, we are almost there… but still some more to go through
I previously had issues with the belts touching the wheels. To come around this I printed plastic shims which acts like a distance for the wheel pulley.
Now the wheel pulley has use of its edge near the wheel, making it impossible for the belt to move further.
I designed my own version of belt covers. They help a lot from keeping small stones out of the belts. This new design is smaller and has even more cover than the old ones.
The old build had bones reds bearings in them. I remember they made terrible noise also they seemed to have gotten worn fast. I think it was due to my crappy wheels had the shape like cones from excessive carving, putting extra stress on the bearings.
I learned how to disassemble bearings and this must be by far the fastest way to clean bearings (instead of shaking them in a bottle).
I took all the tiny balls from each bearing and mixed them all together… then put the bearings back together, greased them up and now they all run smooth and quiet
The fitment of the kingpin and the baseplate of my caliber II clones was horrible. There was so much play and caused massive rattling. I cut small sheets from an aluminium can and folded around the kingpin. Then hammered the kingpin into place. No more wiggles, no more noise!
VX1 got a battery upgrade, and some glue on the solder joints.
Now it is very close to be finished, Its rideable and range is is good. 27km. The riding comfort could be better though
Now this wheel mod is by far my most satisfying achievement of this build.
I cut a bicycle tire into pieces.
…long enough to encircle the wheel
Contact glue on both wheel and tire strip. Wait 10min then attach. Used tension straps around over night.
yesss
I have not done more than 40km yet on these wheels, but I have been stressing them with carving and there is no sign that these tire strips will come off. The ride is now really smooth, I can’t feel the small annoying stones any more… I like it a lot!
The draw back is the 30% decrease in range I got now … but still enough for what this board was built for.
I’m very happy to have resurrected a pile of junk in my drawer to something great
Data
15/36 and the new wheel diameter 87-89mm gives me a top speed of ~38km/h
19km after full depletion.
Power ~2kW
Motor A 2*65A
Batt A 100A
6S
260kv