Snow moped

[Rickard m]

Just started a small new project before the Christmas holidays. It will be a small snow moped. Got so inspired when I stumbled across Moonbikes on the internet. (google it, a light snow vehicle with hub drive) Then I just found a empty dirt bike frame cheaply on an ad, a 2013 KTM 85. No wheels or motor, perfect for my build. I bought an used ski from a snowmobile and mounted to the front. I also have an electric boat motor conversion, I wanted to use that same 48v battery, so I made a box in the original motor position.

 

[Rickard m]

I bought a replacement track and drive wheel from a snow blower at the local hard ware store. I figured out a bolt on unit that should fit inside the original swingarm. Ordered some laser cut steel and welded/screwed it together. The other wheels inside are 120mm kick bike wheels.
Took out the center and sourced the biggest hub motor I could find that fitted inside the wheel. Ordered some water cut spacers to join them together.

 

[Elektrosherpa]

Interesting build :thumb:

Unfortunately, it wouldn't make any sense in my region (lack of snow)

But with a front wheel instead of the front ski (maybe even with its own second hub hotor)
couldn't this be a dirt track vehicle for extremely muddy places?

 

[Rickard m]

Thanks,
I need some help now, cant figure it out with the throttle. The kit I bought came with some kind of finger throttle that I don't want to use, I want to use a twist throttle (that I managed to put a nicer dirt bike grip on to) The problem is that the old one that fit had six wires. Goes inte the "LCD line on the controller. I measured them like in the picture. 48V into the brown, continued into the yellow when power on. Black is earth. Both green and white seems to have ~4,5-4,6 independent of what mode 1/2/3, the red one seems to be throttle signal, show ~0,8 in rest. The new twist throttle came with a white and yellow, and the 3 throttle wire Black/green/red in a separate connector. When I connect to the high voltage, and black, the display light up when I turn on the key. So in total 5 insted of the old six.
I have new six lug connectors so I have tried to connect this new fitting into that "LCD" line from the controller.

White/yellow/black is sorted. But How should I do with the rest?? I assume the new green should go where the old red was, signal. Do I need some kind of extra loop to compensate for lacking one wire? When I connect the new red into where the old connector showed 4,6 volt, I only read ~2, something now. Nothing happens when I twist... I got stuck here. HELP When I jack in the old throttle it works as normal again, but I dont want to use that one Could someone please point out what goes were Thanks,

Or is it best to source a 6 pin throttle? I thought it feel little dangerous to have the finger thing in front of the handlebar, thumb throttles uses to have it on backside for a reason... and I prefer twist.

 

[SlowCo]

Nice build :thumb:

 

[calab]

Very cool indeed

It would be nice to get a full profile (side) view.

I was thinking of making an ice trike for picking metals in the alleys but the tracks is the ticket for deep snow, which around my parts only really happens once or twice a year for a day until the vehicles pack the snow down in the alleys.

 

[larsb]

What functionality does the lcd have, what can it show and do?

Some thoughts to clear the wiring question:
- The two 48v wires gives the battery status, these can be ruled out of the throttle issue

- if throttle signal is red, ground black then you need to find which of the two remaining wires is throttle feed. Since both are at roughly 5V then it could be either so you’ll need to find which one is switched.
That cable will be a function or communication signal, some times it’s lights on/off or brake light, speed mode etc.

the new throttle wiring should match to the correct pins off course so ground meets ground, +5V meets +5V etc. On your new throttle, (if they used the normal colors) then red is +5V, black ground, blueish is signal.
What controller and throttle is it? Ask seller for the info (even if most know knothing about the stuff they are selling) You might find more info here or if you google it. Good luck!

 

[Rickard m]

The engine kit comes from some pretty mad off-road scooter, probably a little too small for this snowmobile, but the ambition is not a mountain goat, but rather to pull the kids' sled a few laps on a nearby football field. It was a complete kit with this throttle and controller etc., it is marked MOS, 50A and lots of Chinese characters . Googled the designation on the display yesterday and found a movie that you could set various settings using combination of the two buttons, so I might start trying it a bit with it anyway, even though I do not want to.

 

[larsb]

Link to your parts and a picture of the controller label would help.

If you’re a button, display and data liker then yes, otherwise you could just skip the functions of the buttons when you’ve gotten the setting you want and use the new throttle.

I don’t care for most of the data except voltage and riding feel so for me that would work

 

[Rickard m]

This was the kit:
https://www.aliexpress.com/item/1005003652843765.html?spm=a2g0o.9042311.0.0.714f4c4dEMoHxH

This was the new throttle I have swapped grip on now, doesn't say much:
https://www.amazon.se/gp/product/B0946TJWK5/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

Don't care about data either, just want to give full throttle :lol:

Or do you think this throttle would fit better? have six wires, in the crap translation it says something ablout one wire should go tho one of the motor phases?
https://www.amazon.se/Gashandtag-LCD-sk%C3%A4rm-Vridna-Nyckelknack-Elcykel/dp/B09LMMJSNG/ref=sr_1_38?crid=1ADUKR5XWY8P7&keywords=gashandtag+6+kablar&qid=1643113298&sprefix=gashandtag+6+kablar%2Caps%2C86&sr=8-38

 

[Elektrosherpa]

This was the new throttle I have swapped grip on now, doesn't say much:
https://www.amazon.se/gp/product/B0946TJWK5/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

...

Or do you think this throttle would fit better? have six wires, in the crap translation it says something ablout one wire should go tho one of the motor phases?
https://www.amazon.se/Gashandtag-LCD-sk%C3%A4rm-Vridna-Nyckelknack-Elcykel/dp/B09LMMJSNG/ref=sr_1_38?crid=1ADUKR5XWY8P7&keywords=gashandtag+6+kablar&qid=1643113298&sprefix=gashandtag+6+kablar%2Caps%2C86&sr=8-38

I would not use any of these throttles.
I would always prefer separate key switches.
The less parts, the less sources for failure...

 

[larsb]

This was the kit:
https://www.aliexpress.com/item/1005003652843765.html?spm=a2g0o.9042311.0.0.714f4c4dEMoHxH

This was the new throttle I have swapped grip on now, doesn't say much:
https://www.amazon.se/gp/product/B0946TJWK5/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

Don't care about data either, just want to give full throttle :lol:

Or do you think this throttle would fit better? have six wires, in the crap translation it says something ablout one wire should go tho one of the motor phases?
https://www.amazon.se/Gashandtag-LCD-sk%C3%A4rm-Vridna-Nyckelknack-Elcykel/dp/B09LMMJSNG/ref=sr_1_38?crid=1ADUKR5XWY8P7&keywords=gashandtag+6+kablar&qid=1643113298&sprefix=gashandtag+6+kablar%2Caps%2C86&sr=8-38

It seems there are too many functions to solve with the amount of wires with simple switching so there has to be a communication to and from the LCD. Should be possible to just try which cable you can remove and still get the LCD to work, that will be the throttle feed wire.

(the other 6wire throttle won't help your issue.)

 

[Rickard m]

Yes seems quite complex, Maybe I could keep that unit inside my Swingarm box and just run a 3 pin throttle to the handlebar.
(Real snow bikes usually have a spare fuel there, so I thought it would be a good idea to place some stuff in a box there now as well.)

Oh by the way, the bike got soo small when I lifted it down from the dirt bike stand :lol: My youngest daughter almost reached down when it sprung down (she has her foot on the stool there.) let it snow soon please

 

[Rickard m]

Another question for you, what do you think about tweaking a motor like this with a little more amperes? Since I already had a 48v battery, (with100A BMS) I chose the so-called "2000w kit", but the same motor seems to be sold in 3500w version, when you give it 72volts. How would it work instead if I get a slightly better controller and give it, for example, 80A instead of the maximum 50 that it will probably get now? Overheating will probably not be such a big problem as it is a winter toy...

 

[larsb]

sure, it could be done like that, just get a programmable controller and ease up the amps until you start heating things, then back off a bit (or even better install a heat sensor in the motor, get a controller with heat limiting and increase the amps gradually until you get current limiting during your toughest type of riding)

 

[TommyCat]

I agree with larsb that your throttle need a proper 5vdc supply voltage.
Your display is a programmable model with the 4.6vdc wires being the TX and RX communication wires. As you've found, unsuitable for the throttle's supply.

Now I've seen mods made on this type of display where the new throttle cable is taken directly into the display's housing.
With the finger throttle removed, and the new throttle's wiring taking its place. Just hook the 3 wires up accordingly with the diagram below... (I.E. the display has a 5vdc supply internally) You could also splice your key switch in at the same time, in series with the 48 wire.

If you think that you can do without any of the features that the display provides. Remove the display and install your key switch between the 48 and ---> wires. (BROWN and YELLOW)
You'll have to get the 5vdc from the controller though... either internally at a 5 or 4.3vdc pad. Or externally at the motor's hall sensor supply. The RED and BLACK wires.

You may also have to short the receive wire (RX) to ground. I speculate that this display is much like a KT controller's display...

If you're really determined to get it working NOW. Put 3-1.5vdc batteries together in series for 4.5vdc. Connect the throttle's RED wire to batteries + , GREEN to displays connector .8 (looks RED), and the BLACK to display connector ground. (yes, both grounds need to be connected...) And tape the battery pack somewhere to give it a try. (you need to see .8vdc at closed throttle to ~3.6vdc WOT at the .8 connector wire.)

For more in depth details on hall sensor throttles and how they work, see this thread...
Guide to Hall Sensor Throttle operation, testing, and modification.

Hopefully I've made myself clear. But if any questions, please ask BEFORE wiring...


Regards,
T.C.

 

[Rickard m]

thank you so much for your detailed answer! That sounds logical.
I will now first wait for snow and test drive a bit as it is now, probably I will want a little more power so it will surely land in that I change controller and then it will surely be one with a separate throttle 3pin connector so then some of the throttles I have in stock would work, I hope .

 

[Rickard m]

Not much else has happened with this one, but now there was some snow in Stockholm so I wanted to try again. I bought myself a FARDRIVER ND72360 Controller. to be able to force feed the little engine a little more. First, the phase cables melted , so I changed them to a bit thicker ones and turned the amps down a bit. But it is so boring, weak at the start, and goes slowly as soon as it gets heavy. Is there some obvious parameter that I don't understand that could get all possible power directly. Now the little motor stalls if I hold it. Unfortunately, I couldn't fit anything bigger one inside the drive wheel for the short snow blower track I used. 11 inch 60H seems to give around 3000W. Do you think this is stupid, and doomed to fail, so I can settle for the fact that it was fun to build . I don't understand which parameters in the app might make it more explosive?

 

[Rickard m]

https://imgur.com/a/ejriE0z

 

[fechter]

Cool.
How does it ride?

 

[harrisonpatm]

My biggest issue with this post is that nobody has called it "snowped" yet. What a waste!

 

[dominik h]

More phase current gives more starting tourque.

 

[Rickard m]

Cool.
How does it ride?

Yes that’s my problem, it looks cooler than it goes.., ok on flat but slow in start and uphill

 

[Rickard m]

More phase current gives more starting tourque.

Ok! I will try to turn that one up, hope I don’t melt anything any other parameter that hold back throttle response?

 

[dominik h]

Is your throttle mode set to sport?