Like the one or other already knows, I’m a big fan of using an external smart bms for charging over the bms implemented into the enclosure/box.
So it was about time to design a proper housing for them.
On the left it’s the V1 which is a bit on the bigger side, but includes a LCD voltage display. With it it’s easy to check voltage and no need to always open the app. On the right side there is V2 which is more on the compact side. Really like how the V2 came out.
Also got me a new charger.
After I broke the display on my big balance hobby charger last year (damaged during transportation on a trip) I wanted something I can easy take with me on weekend trips without need to worry that something will be broken.
It’s a 12s 12A charger which let me change the current from 2-12A depending on which pack I do want to charge and how much time I have for charging.
Not the most compact one, but is looking solid.
Also, if you change a charge port on your charger before having ever used the charger, check the polarity first.
The output cables on mine have been blue and brown. Coming from AC wiring, I was like, sweet, than plus should be brown, negative blue
Decided to double check with the multimeter and it was exactly the opposite.
I did a bit of research after and it seems that this is common use in car installations etc.
So always check polarity if you are not sure.
Too much going on the last weeks, so just little time to work on my boards, but I finally made it to finish a small lipo battery box for jump sessions.
The display has attached a temp sensor which is fixed in the box and will show the voltage as well as the temperature. Looking forward to see how hot the packs really get when I push them hard.
Was always wondering, so I guess I soon can find out.
Things are not really getting better.
Rough weeks… needed to sell a lot of my esk8 stuff and my 3D printer, but I finally made it through and packed up everything. With a bit luck my belongings are going to be picked up next week and it will take about a month till everything arrives in Germany. So the next weeks I’ll be out of building for real.
Ok ok, maybe I still can manage to do the silicone mold I was planning to do in the next days
I need those custom bushings
Had a nice forest ride yesterday with a friend.
One of the best I had so far. Loads of hills and different terrain.
Unfortunately one of my mbs bindings gave up pretty much after 5km in.
Close to the end I had a fatal break down.
First thought the esc popped or something locked up the chain…. But no, the bolts holding the hub together all broke off.
Had a good 18m slide no crash luckily
We kind a fixed that as well but couldn’t inflate the tire, so had to ride back to the car with a flat tire.
Guess the next days I have to fix some stuff. Sadly most of my esk8 stuff isn’t with me anymore, so I have to find a temporary solution to the broken binding. Probably will try my luck with a snowboard binding strap. Hope that’s going to work out.
There is as well slow progress on my main long term project.
Hope I can soon share some more info on that one.
For it I need some custom bushings.
Luckily one of my friends here has some experience in doing stuff with polyurethane and did help me out.
I did 3D print some prototypes which we than used to make a silicone mold.
That one was than used to do the actual bushings.
They are not perfect and it’s hard to get all the air bubbles out while pouring the polyurethane, but I’m confident they will do their job.
Time for some update on my quad rebuilding plan.
All started off with the fact that I needed wider trucks to not get wheel bite when using studs on my tires. Plus I was a bit concerned about my barrels popping out the fixation during strong lean.
I reached out to Jens, but at that time he didn’t really plan to make more of his 400mm trucks (things changed by now I guess).
So I thought, why not just to try to design my own hanger which will be maybe not so pretty, but does the job.
As I was designing the hanger, I realized, I should as well replace the motors.
So I started to work on some double stage chain drive system which should work with my inrunner.
I did design the first version pretty quick. Than things where laying on my table for some months without anything happening…
As the one or other might know, I have quite a bit time right now, but no boards to work on….
That made me to expand that original project to a full frame quad.
At this point I need to place a big thanks to Jens (Etoxx) and Duffman for the inspiration.
I‘m not a mechanic or designer, so I tried to hold things as simple as possible and I unfortunately also can’t present any fancy renders.
Well, this is the concept:
Let’s get to the specs:
4x 11“ Gokart tires
1:16,4 gearing
4x inrunner
4x Little focer
18s 22Ah 30c Tattu lipos
I‘m happy that @Creavenger is helping me out and will try to cnc the hanger.
With a bit luck, we can as well get the parts for the frame water jet cut.
Besides the hanger, all other parts are in the early design stage, so I’d be happy on some feedback from you guys.
Points I‘d like to discuss:
Hight of the frame. Does it look ok, or better move it more down, so less clearance, but center of gravity will sit more low as well.
to use my 360kV inrunner, or better to get some 220kV? Changes in gearing ratio still can be made from a range of 1:11-1:20 and top speed isn’t what I’m looking for. Just curious as it seems that closer to 200kV seem to work better with VESC based escs.
18s Tattu lipos, or 18s8p p42a pack?
P42a would be cheaper plus more range, but I need to build the pack and not sure what the sag will look like.
Any other feedback on that design is very welcome as well!
Drop the frame a touch you’ll want your ‘deck’ to nearly be in line with the hanger axles.
raise the center hump (you’ll tend to bind up in this spot on rough terrain)
06b chain or bigger is needed for duel stage imo
you’ll also want to bring the wheel wheel base in, compared to where your feet sit.
and cross brace everything the two stages and between the two sides, stage puts an unruly amount of force on the mounts to the point the second stage will twist and then bend towards the wheel.
Imo lipo for the amps coz who doesn’t like ankle breaking torque, you can also get watercooling jackets for sss inrunners
Good points!
Was thinking about the watercooling as well.
Not sure if it’s really needed on a quad.
We will see, definitely holding that in mind for future upgrade in case.
personally i have found boards where the deck is lower handle better
longboard with a top mounted deck felt worst then the same setup with drop through and spacers to lower it more. same with mtbs i found that having the deck inline with the axles felt amazing where as my one with 8" of deck ground clearance felt less planted, if you get me
Small update on the design.
As mentioned in other threads, I gave it a try to integrate some damper. Big question was first, should I go with spring or air damper. For my liking, spring would be more easy because of less maintenance and cheaper, but air would give me more options for adjustment without need of buying and replacing different springs. For me as noob doing things like that the first time, I might be better going the air damper way. If somebody can give me good recommendations on spring damper, I might reconsider my choice of course.
The damper of choice is a rockshox Monarch RL 184x44. https://r2-bike.com/ROCKSHOX-Daempfer-Monarch-RL-Tune-Mid-Reb-Mid-Comp-184-x-44-mm
If I understood right, 44 means maximum travel of 44mm. With preload should be 20-30% of the total 44mm.
Here some pictures of my current design (still missing some support bolts etc. but that’s the rough idea)
Without preload:
I‘m also not yet set on the bushings I should use on the axles. If anybody can recommend something, please go ahead!
What I could found on that topic so far, is either to use flanged bushings with PTFE liner, like this
Regarding the SSS Inrunner question please don’t run 360kv. Shaman has said these Lfoc and Tronic25-'s LOVE lower kv. The lower the better. Sub 250kv is the best from what I was suggested
