Yamaha YZ250F

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larsb   100 MW

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Re: Yamaha YZ250F

Post by larsb » Aug 19 2022 2:07pm

but how many volts are we talking? There should logically be a significant step between the different controllers or they wouldn’t be built?

j bjork   1 MW

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Re: Yamaha YZ250F

Post by j bjork » Aug 19 2022 2:27pm

I think max voltage for the 1081800 is 130,8V before it trips, that is what the app shows before I connect to the controller.
I would be happy with 125 or so, or at least be able to charge to 4,1v per cell (123v)
Now it trips at 121,5v according to the controller, the bms reads 120,5v.

I tried talking to siaecosys about raising the limit a little at my own risk, as there are no 108v controllers available.
Or at least be able to change the calibration so it shows the same as the bms.
But all I got was that I was wrong with my battery voltages, max voltage on my controller is 117V :|

Jocke_D   10 mW

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Re: Yamaha YZ250F

Post by Jocke_D » Aug 23 2022 6:46am

Super cool!
This could make me travel down south and watch you race :)
I've done Ränneslätt four or five times and it is NOT my favourite, feels like boulders everywhere. Except for the area surrounding the start/finish.

j bjork   1 MW

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Re: Yamaha YZ250F

Post by j bjork » Aug 24 2022 12:16am

You are welcome here, I can use a pit crew :mrgreen:
I looked at a better quality film clip yesterday, and I think I see what you mean..
I hadn't really seen all the rocks before.
This from about 6min is pretty good: https://www.youtube.com/watch?v=GXDOZEjRMEM

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Re: Yamaha YZ250F

Post by j bjork » Aug 26 2022 12:46pm

The bike has got new front wheel bearings, and I couldnt keep my fingers from the primary reduction:

Image

Looks alright, but I want to tension the chain a little.
It was impossible to move the motor even a little though, I think I will wait until I change sprockets.
The rubber seal dosent look to good though:

Image

Gasket material that cant handle oil :?
I made a new gasket from paper gasket material, it dosent seem to keep tight though.
I get a little oil on the finger if I drag it along the edge, and it hasnt even been warm yet.
I guess I will see how it works after the weekend.

Building another charger:

Image

At first I thought I would just have it for extra, maybe setup for other currents.
But then I realized I need 2 chargers when I have 2 batteries, so I dont have to wait for one the finish charging before I can charge the other one :wink:

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JRP3   100 W

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Re: Yamaha YZ250F

Post by JRP3 » Aug 26 2022 3:54pm

Why not use RTV for the gasket?
Building the AMPhibian http://amp-phibian.blogspot.com/

dominik h   100 W

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Re: Yamaha YZ250F

Post by dominik h » Aug 27 2022 8:13am

What power supply are you using as a charger?

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Re: Yamaha YZ250F

Post by j bjork » Aug 27 2022 12:53pm

JRP3 wrote:
Aug 26 2022 3:54pm
Why not use RTV for the gasket?
Because it is such a mess every time I want to take the cover off.
I might go back to silicone "rtv" when I feel I dont have to check the chain etc. very often.
But for now I want to easily take off the cover and a look now and then.
dominik h wrote:
Aug 27 2022 8:13am
What power supply are you using as a charger?


I am using Eaton APR48-3G 1,8kW because of the voltage hack so I can get higher than 58V each out of them, and that I know how to program them. It is a little inconvenient that I have to program them to get another current though.
I series connect 2 of them, set to a little over 60v each.

Im very interested in how to hack other models if you know :)
I have huawei R4050G2 too, but I only know how to control them with an external controller. And I am limited to about 58V each on them.

dominik h   100 W

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Re: Yamaha YZ250F

Post by dominik h » Aug 27 2022 1:58pm

Huawei is a simple CAN Adress to set the Voltage and an Adress to set the current you want. But only from 48 to 58,5V when offline limits are used. Don't know how to get more volts out of them. They all only have 63V caps. Except the eltek 48-60V 2kW flatpack2 HE these have 80V caps and can do 72V. But they are to expensive

I have also a chinese moded Huawei which can do 90V. It's dead and I am not able to find the failure.

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Re: Yamaha YZ250F

Post by j bjork » Aug 28 2022 1:29pm

Maybe I should look for those 48-60v flatpack2, and see what price range we are talking about.
I would like some 3kw psu:s that could do a little over 60v and be adjustable though.

I also have one of those modded Huawei, but up to 120v. It drops in voltage during use now, so it stops charging.
For example if I set it to 90v and charge, after a while I notice it has stopped charging. If I then unplug the dc connection and measure I might get 78v output.

Today was the last practice before the race :?
It started raining yesterday, and it was thunder and heavy rain all night. It continued raining more or less all day today.
There was a warning for high water-flows in the area.

So we decided it was a good idea to go to a track with quite a lot of rocks, roots and mountain climbs to practice wet rock climbing :mrgreen:
We were alone there all day, no one else seemed to think it was a good idea to go out riding for some reason..

dominik h   100 W

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Re: Yamaha YZ250F

Post by dominik h » Aug 28 2022 2:25pm

You could go for a setup with two huawei 48V in series with a 24V huawei. Only problem is that you always have to power on the PSUs before you plug in the batterie, as the PSUs could be damaged through unequal charging of the output caps.

Megmeet has also a rectifier with 72V 3kW but they have not even listed it on their Homepage.
Last edited by dominik h on Sep 02 2022 3:34pm, edited 1 time in total.

j bjork   1 MW

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Re: Yamaha YZ250F

Post by j bjork » Sep 02 2022 2:18pm

dominik h wrote:
Aug 28 2022 2:25pm
You could go for a setup with two huawei 48V in series with a 24V huawei. Only problem is that you always have to power on the PSUs before you plug in the batterie, as the PSUs could be damaged through unequal charging of the output caps.

Megmeet has also a rectifier with 72V 3kW but they have not even listed it on their Homepage.
I power up the psu:s before I connect them to the battery now too, but I didnt think about uneven charging of the caps.
Just that the voltages were closer, so smaller spark :)
What do you use to program huawei?

Getting ready for ränneslätt:

Image

Another testcharge with the generator. Only 15A this time so I dont stress things too much.
Also got my numbers on the bike.
570 of 658 starting at the same time :shock:
Might as well be far to the back, less risk of being run over at the start :roll:

My charger now:

Image

I decided I want a meter on it so I can see were I am without reading it from the bms.
Especially when charging during a race..
I hope no one sees it and deem it unsafe :?
I have an extra output wiring so I can just take off the shunt and meter in that case.

I will make a cover for it, but I dont have time now.

dominik h   100 W

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Re: Yamaha YZ250F

Post by dominik h » Sep 02 2022 3:32pm

For the Huawei i use a USB to CAN-BUS converter. Canalyst 2
It is a clone but works ok after downloading the software from the link on the package.
But i think every other will do the job.

You can also look for the eltek Flatpack 2 110-125 2000W
adjustable range from the eltek Homepage is
89,2 - 171,6 VDC but in person I never had one of them.
Max current 16,7A.

j bjork   1 MW

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Re: Yamaha YZ250F

Post by j bjork » Sep 04 2022 9:24am

A little race rapport from yesterdays ränneslätt.
I had a cold that had been lurking in the background, but it broke out on Friday :?
So that sure took me down, and I didnt sleep much the night before.

When I got to the pit they had arranged a corner for me (according to the rules it should be a 100m from the others), and there was electricity. Very nice, but I wish they had told me so I didnt have to buy the generator..

It was very hard to change batteries by myself when I was already tired, a pit crew would have been very good to have.
I had one repair job:

Image

Damn, it hurted to hold the grip when the skin is gone :flame:
I had wire, zip ties and duct tape in the pit.
Duct tape worked worked fine and seemed most suitable :wink:

A little film for those interested:
https://youtu.be/RH4tAe5RDdE
https://youtu.be/3XerNa_Lbhs

I didnt do very good times, but at least I didnt chicken out when tings got tight this time :)

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tylerwatts   100 W

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Re: Yamaha YZ250F

Post by tylerwatts » Sep 04 2022 3:40pm

Well done Jonas
Nice thing for endurance isn't full throttle all day, sorry you had the cold but you caught back. Looks like a nice event if you aren't competing hard and can relax but riding hard the whole time is tiring. Keep you fit
Bike seems to be doing well.
Congrats and hope you are well soon!

cheers
Tyler


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Re: Yamaha YZ250F

Post by j bjork » Sep 05 2022 1:06pm

Thanks :)
The crash on the mountain (27min in) looks nasty, hope he is ok :o

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Re: Yamaha YZ250F

Post by dougf » Sep 05 2022 5:44pm

Nice one mate. Glad no serious technical issues with the bike. I havent had a blister since I fitted my flexx bars. They are expensive but good.

For trackside charging I got myself one of these;

https://www.wsepo.com/products/wse2000i ... p-function

Actually works great. Plug it in, auto starts from the batt pack, charges at about 20A and when done the motor switches off. No external chargers at all. I regret only getting the 2kW one but it does the job.

Doug

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liveforphysics   100 GW

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Re: Yamaha YZ250F

Post by liveforphysics » Sep 05 2022 11:50pm

Fantastic racing! Great job at making your own bike and kicking ass with it!!! Woot!!!

What a terrific accomplishment to build and race your own powertrain!

-Luke
Each carcinogen vapor exposure includes a dice roll for cancer.

Each mutagen vapor exposure includes a dice roll for reproductive genetic defects in your children.

Each engine start sprays them into a shared atmosphere which includes beings not offered an opportunity to consent accepting these cancer experiences and defective genetics life experiences.

Every post is a free gift to the collective of minds composing the living bleeding edge of LEV development on our spaceship.

j bjork   1 MW

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Re: Yamaha YZ250F

Post by j bjork » Sep 08 2022 12:20am

Thanks guys :)

That charger looks like a real find, there is a 4,5kw version too.
And cheap, a lot cheaper than my solution..

Can you adjust the output V and A?

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Re: Yamaha YZ250F

Post by j bjork » Sep 11 2022 9:28am

Today is sprocket day :lol:

Image

Jt sprocket only have these kind in 14-17 tooth. Dougf told me about MXT sprockets, that has a 13 tooth. Those seems to only be available in Australia and New Zealand. Then I found these, from "France equipment" (not French equipment) that were available in 13-18 tooth.
So I ordered 13 and 18 from France, and didnt get a confirmation or anything. When it had been about 2 weeks I started wondering, but then suddenly there it was in my mailbox :)

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The 10 and 17 tooth I have been running so far. The 17 looks new, but the 10 tooth have some wear. It is only mild steel, so it dont seem to last even when it runs in oil.

Image

Made a thin (0,4mm) paper gasket, so I will be able to tension the chain this time.
I can only hope it wont leak..

Image

How it looks now. I hope the chain wont rub with the 18tooth, there was no marks at all after running the 17 tooth.

Image

Finally a kickstand, I have been waiting for that :)
Also changed the front secondary sprocket to 11tooth from 12tooth to compensate for the higher primary gearing.
I will still go from 7,1:1 to 6,3:1. A 11tooth 428 gear would be a nice find..

Those 11tooth 520 was also a little hard to find (jt has them), but amazon had 3.
I ordered them all, and they sent them in 3 different envelopes from the same facility it seems :o

I have got 2 of them, from different shipping companies. One was not closed properly and was empty..
I made a complaint, and should now send back the empty envelope to USA.
But now it looks like I have got 2 of the 3, and that it is the 3:d that should be sent back :?
I guess I will have to wait and see how this ends..

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Re: Yamaha YZ250F

Post by E-Max » Sep 15 2022 4:43am

Hi guys,
I read through the whole thread and I think this is an amazing project and really well done. It really looks like it came fresh out of a factory👍.

I am planning to convert a 125cc shifter-kart with this motor and I am not sure which controller to choose. Is the motor capable of using the whole 1500/1800 pA of the ND961800 or what it the max pA it can handle before it goes into saturation?
I would also consider a 108V controller but I'm not sure if its needed.

Max

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Re: Yamaha YZ250F

Post by j bjork » Sep 15 2022 12:48pm

Thank you :)

Well, I dont really know what the motor can take. I dont even know how much phase amps I have fed it, if I even have hit full throttle it has only been for a second.
You can always try to get dougf to put his bike on the dyno :wink:

The higher the voltage the harder to find controllers..
I have the sevcon size6 if you are interested, it has a lot more possibilities if you are up for a challenge :)

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Re: Yamaha YZ250F

Post by dougf » Sep 15 2022 5:15pm

j bjork wrote:
Sep 15 2022 12:48pm
Thank you :)

Well, I dont really know what the motor can take. I dont even know how much phase amps I have fed it, if I even have hit full throttle it has only been for a second.
You can always try to get dougf to put his bike on the dyno :wink:

The higher the voltage the harder to find controllers..
I have the sevcon size6 if you are interested, it has a lot more possibilities if you are up for a challenge :)
it will happen soon. Just need to build the stairs for the mez. Drags are also back open so can probably try for a clean run without turning the battery into a furnace.

That petrol charger, no V and A adjustment, at least no on the front panel. Best ask the guys as WSEPO if your interested.

Hows the lower gear ratio feel?

Doug

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Re: Yamaha YZ250F

Post by TysonScott » Sep 15 2022 5:26pm

E-Max wrote:
Sep 15 2022 4:43am
Hi guys,
I read through the whole thread and I think this is an amazing project and really well done. It really looks like it came fresh out of a factory👍.

I am planning to convert a 125cc shifter-kart with this motor and I am not sure which controller to choose. Is the motor capable of using the whole 1500/1800 pA of the ND961800 or what it the max pA it can handle before it goes into saturation?
I would also consider a 108V controller but I'm not sure if its needed.

Max
https://www.facebook.com/groups/electri ... 911125831/
this person used a qs 180 90h with ND961800 pushing around 100kw! that would be pretty insane on a shifter kart

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Re: Yamaha YZ250F

Post by j bjork » Sep 16 2022 4:07am

Doug, how do you limit the charge then? (I think you were running 24s?) Do you guard it and turn it off when it is done, or let the bms cut if necessary?
I dont think I will buy one, but I am curious anyway :wink:

I havent really tested the new gearing yet, it will probably be this weekend.

Tyson, I have seen that one before :)
Very cool bike, but is it possible with that short wheelbase and skinny tire?
I dont know what to make of it, if it has the track version the controller should be capable of 100kw.
When I was messing with the sevcon it seemed like the motor was limited because of its higher inductance compared to a z-force 75-7 for example.

It is also interesting that he seems to have the earlier, 28Ah version of passat gte cell modules. Where I have the newer 37Ah version, that in my limited test had lower ir than the earlier ones :)

A 10.2x and 210km/h run in sneakers, jeans and a sweatshirt :?

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