I was gonna say tear into it and investigate and at least harvest that smart 14s bms, and recycle the cells, but there is danger involved in this process if one were to be careless, and I have seen your shenanigan’s with JST plugs and Vescs.
So wrap the xt60 or 90 and balance connector with electrical tape and take it to your local lithium recycling center like a Lowes or home depot/UbreakIfix, and store it outside until it is gone.
Sounds like Grandpa has got some skills.
Maybe tear it down together.
You WILL learn something, and get to spend time with him, which could make him very happy.
Is limiting ERPM an acceptable way to temporarily reduce the top speed of your board? Had an issue on Tuesday where someone else was riding it. He got my Agent build up to around 45mph on asphalt. Instead of gradually rolling the thumb wheel back, he completely let off the throttle. You can guess what happened. Luckily there was soft dirt next to the road, guessing he hit that at around 30mph. He was OK but I don’t want someone else getting hurt on my board.
Poking around on here, ERPM seems to be the setting to reduce top speed. Is there any risk to doing it, like would throttle just suddenly cut out toward the top end? Would duty cycle current limit start be a better setting to change? I don’t mind sharing but that scared the shit out of me.
Edit to add, just found this thread.
Still not clear if there are any risks associated with it. If there’s risk associated with it I can just throw in a 12s battery if someone else is riding it.
I think duty cycle limiting might be “better” than ERPM. Try setting it at like 15% duty cycle or something and do a test ride. ERPM limiting can be kinda funky. @Dinnye tried limiting ERPM on the D100s and it popped when he free spun it.
Edit: I don’t know much about limiting the duty cycle/ERPM so do it at your own risk. I’d say best way to do it is tell them if you crash you buy.
Jokes aside maybe increasing the Negative Ramp Time to something like 0.3 or 0.4 for less abruptive deceleration when letting off throttle?
Yeah duty cycle limit start is a good way to limit it
You can also change to a profile with lower acceleration via the vesc app or from metr or from remote. I have a “friends” mode on metr with lower phase current , lower duty cycle limit etc.
He’s been eskating for years but only his second time on that board, or anything with some real power. He’s used to his propel. I’ve never messed with profiles, sounds convenient. Will check it out!
Sounds like increasing negative ramping time would really help here. It essentially emulates gradually letting off the throttle. I personally prefer it at 0.25s which is a tiny bit more than default. Small changes in that setting will give big differences in terms of ride feel, I would change it in increments of 0.05 until it feels good.
Duty limiting is much more stable than ERPM limiting.
I’d reduce maximum duty cycle to your desired top speed and duty cycle current limit start to 10% below that number
Oh I’ve never adjusted negative ramping but that makes sense, might have prevented the whole thing. I really just don’t want anyone hitting those speeds in the first place though, especially someone I don’t know very well. I’ll try to limit it to 30mph when loaning it out. Thanks for the detailed breakdown of how to cap duty cycle.
Even 30 mph is pretty sketchy if they’re not very experienced.
Does negative ramping time also apply to braking? I’m too lazy to check my settings, but I think I have mine very low because I figured if I want to break, I want to brake. I also don’t use smart reverse, though, and that can make reversing a bit twitchy if you’re not careful, which is a downside.
Is there a ramping time for dummies guide anywhere? I used to remember what was what but haven’t had to program a board in a while. Would be nice having a simple guide showing what different ramping times accomplish
@HAIRYMANJACK gave this to me a bit back and feel like it’s perfectly explained.
“ Ramp time refers to an added delay / smoothing filter to your given inputs. Positive ramp time refers to the time it takes from an output closer to zero ( or zero exactly) to an output further from zero. This applies to both acceleration and braking.
So say I have a .05 ramp time and I’m at a start line and the lights go off. I slam the throttle to full and this input is given to my escs which then take that input and add that .05 ramp onto it. Making the acceleration a bit more bearable. The same thing applies to brakes too, say I slam on the brakes, it’s gonna take .05 seconds to give me my desired output. Having this too high will have a very mellow, sluggish response to the board and having it too low can cause jerkyness and twitchiness which some people like (myself included).
Having a remote with a spring that has a bit of rebound (say you’re doing full throttle then let go, it won’t immediately go back to center, will actually bounce into the brakes momentarily) can lead to an undesirable affect with too low ramp time where it will actually brake you slightly and cause a really nasty jerking affect where one moment you’re being given throttle then the next you’re being jerked to a braking force then back to neutral. This usually isn’t a problem with harder springs. Softer ones like the one I put in my puck experience this hence why I keep my ramp time at .05 and don’t go lower.
Negative ramp time refers to the delay or smoothing filter added to an input that changes from a point that is further away from zero to a point that is closer, once again applying to throttle and brakes.
An example of this is letting off the throttle from a higher position to say neutral, like accelerating then letting go. The default of this is .2 and I recommend keeping it roughly there.
Lowering it can cause undesirable jerkyness with sudden loss of acceleration or braking where you would expect it to ramp down a little bit. Having it too high can cause a sluggishness in terms of the board not ramping down fast enough like still giving throttle when you’re expecting it to not. Playing with this value generally recommended within .01 increments but should still keep it within .23 to .17”
