New Veteran "Abrams" 22-inch Wheel

[Kekafuch]

17 hours ago, techyiam said:

Actually, the tire beads on my Abrams are glued to the rim.

If your tire beads aren’t glued on, does your tire loses air?

Thank you for sharing your insight. On my Abrams, the mounting holes of the battery cases/side covers don’t line up with the screw holes in the frame. So there are a lot of stresses placed on the plastic covers. Now that I know they can crack, I will have to do something about that.

I will have to look into it more carefully to determine how to best resolve the mounting issues with the battery covers.

How are you liking your Abrams?

I find that the more I ride it, the more I like it.

Other than how refined and planted it feels at speeds, I can’t get over how great it can brake with the front bar.

 

The glue is obvious to see? My finger felt nothing along the rim or the tire. I have 5000km on the wheel and filled air less than a handful of times. 
 

i really like the Abrams ride characteristics. It actually loads into my car easier cause I park it in the front passenger footwell and I just roll it in. Fast charging is nice at 16amps. The wheel looks good. Feels safe riding in traffic. Avg speed is 5-8kmh faster than riding Sherman. Common fasteners. Control box is spotless. Runs cool. Great headlight. My axle is not sealed and inside the motor was dry and dirt free. 
 

When I got it, it was a bit over priced in my opinion. For $2999 Canadian, I think this is a good wheel if the 60-80km is range is enough. Also seems like a good platform to mod.

 

[techyiam]

4 minutes ago, Kekafuch said:

The glue is obvious to see? My finger felt nothing along the rim or the tire. I have 5000km on the wheel and filled air less than a handful of times.

No, I cannot see the glue. But if the tire is completely deflated, and the tire bead is not glued onto the rim, the tire bead would come off the rim by itself if you roll the wheel a bit. To properly seat the tire bead onto the rim again, I would have to remove the tire valve stem and pressurized the tire with a nozzle at a high air pressure.

12 minutes ago, Kekafuch said:

Feels safe riding in traffic. Avg speed is 5-8kmh faster than riding Sherman. Common fasteners. Control box is spotless. Runs cool. Great headlight.

+1. That headlight is so much better than my V12. If I turn on bright-beam, it's bright. I don't call it high beam because the beam pattern is exactly the same, but a lot brighter.

15 minutes ago, Kekafuch said:

My axle is not sealed and inside the motor was dry and dirt free. 

Good to know. I still have to do mine. 

[Jonah Hax]

On 3/16/2023 at 8:52 PM, Kekafuch said:

Fast charging is nice at 16amps.

 

16 amps???? I heard 15 amps was max but they don't recommend to go over 12 amps?

 

[Kekafuch]

 

[Chaky]

Hi everyone... 

Is there anyone who tried to stiffen the chasis? It really looks and feels flimsy. 

[RagingGrandpa]

14 minutes ago, Chaky said:

Is there anyone who tried to stiffen the chasis?

Regarding which EUC? 

[Chaky]

Veteran Abrams... 

I have one which "survived" crash, but is dislocated. I can easily scrape inner plastic part when steering the shell little harder. I also saw few comments that other people have the same issue. 

[techyiam]

14 hours ago, Chaky said:

Veteran Abrams... 

I have one which "survived" crash, but is dislocated. I can easily scrape inner plastic part when steering the shell little harder. I also saw few comments that other people have the same issue. 

We have Kevin (euc upgrades) to thank for that.

Originally, the bottom cross member was made from steel. Kevin complained that potentially it can rust. His complaint got back to Leaper Kim. Leaper Kim decided to make that structural component from aluminum alloy instead of steel, but made no other design changes. Yup, same dimensions even though aluminum alloy is a lot weaker than steel, and can fail in fatigue. This means the material can get weaker over time under load, especially if there is stress reversal. Also, when designing with aluminum alloy, typically designers use geometry to their advantage in order to minimize stress risers and maximum stresses. 

Edited April 28, 2023 by techyiam

[Chaky]

In my oppinion, there are few miss-points in the structure, and the biggest reason for flimsiness are too long and too week roll bars which should transfer  the axial "steering momentum" to the horizontal carrier. Also, central plastic mud protector could provide some stiffnes if it was more sturdier and connected to the control board housing. 

It is incredible for me that the forces from comming from mass of this heavy wheel in crash situation is concentrated on the 4 tiny screws marked in red. 

Roll bar/frame horizontal interconnections are also too weak and easily get deformed if crashed. 

Maybe this would work for 15kg wheel, but for this heavy beast it could be better. 

Edited April 28, 2023 by Chaky

[techyiam]

I rather see the four inexpensive screws sheering off than cracking the expensive controller module casing. Nothing wrong with using sacrificial screws.

First of all, if seated riding is not considered, then the main structural members that has to support the main load (the rider), is just the pedal hangers and the pedals themselves. The weight of the controller and battery packs would be considered secondary load. And the structure to support that doesn't has to be as strong.

Since, I have never sat on my Abrams, I find the ridgity of the chassis good. I have no complaints, even when making sharp turns as fast as I can. My Abrams still feel like a solid piece.

16 minutes ago, Chaky said:

the biggest reason for flimsiness are too long and too week roll bars

I disagree here. Those steel tubing are ridgid enough IMO. That is not the weakest link.

People resolve the filmsy side-to-side movement issue by replacing the bottom cross members.

[Chaky]

Steel tuning, imo, only look rigid... They are thin walled and interconecting plate are also thin and easily get deformed. When you lift the whole thing, you would expect more weight in it

[techyiam]

On 4/28/2023 at 1:40 AM, Chaky said:

They are thin walled and interconecting plate are also thin and easily get deformed. When you lift the whole thing, you would expect more weight in it

Have you ever lifted up a chromoly bike frame? It weighs almost nothing. Are you saying they are not strong? 

Steel tubings can be very strong and ridgid, depending on the alloying elements and heat treatment. 

Going back to the Abrams, structurally, it isn't the weakest link. But since it just a steel tube, you can easily get a local shop to fabricate something stronger for you.

Edited May 1, 2023 by techyiam

[Chaky]

Few update and oppinions on the cut-out issue... 

I have the one which easily gets cut out and hall sensor error when doing the hard break or pendulum test. 

I've oppend the motor and noticed few interesting observations. 

In my case, Mid sensor is mounted very close to rotor magnets when motor is assembled. I believe this is due to wide gap of the mounting groove. Due to machining miss tolerances(reason can be many... Bearing cover, centering holes, rim geometry, stator outer diameter, etc...) stator is scraping against the rotor magnets, and in one point it also scraped the sensor itself. I've also noticed strange magnet damages on the rotor (will put some pictures later). 

My theory is that this contract between the two assembles is causing the sensor to be moved, and in some situations give false reading which leads to cut out. I guess that it takes time for material to wear enough to get to this situation, and this could be the reason why people have the cuts after 1000+ km when hitting the small road bumps. 

I've also noticed that mid sensor was easily pulled out when disassembling and was not firmly connected to the stator anymore. 

Faulty sensors are not due to sensors per se, but I believe the reason is rotor to stator centering miss match or/and geometry of the stator not beeing perfect. 

I am working on the wheel now, and waiting the new sensors to arrive. 

My plan is to slighlty sand paper areas on stator where the wearing out is and with the new sensors the wheel should be safe to ride. 

Btw, I already cut the yellow sensor wires before taking the picture

And another point-mine is 2110 version of motor and still has sensors with pcb. 

In the end, I think that miss matched bearing covers/machining is the root cause for this issue, and for fast bearing fail aswell because the axle is not perfectly normal to the rim. I will try to confirm this with more data and measuring. 

[mrelwood]

6 hours ago, Chaky said:

stator is scraping against the rotor magnets

There is a little leeway with the motor cover seatings, so if the stator/rotator isn’t centered properly before tightening the motor cover bolts, the rotator can be offset enough for it to scratch the stator.

 I’m not sure if centering is enough in your case, but it would be the first path I’d examine. Print paper strips bent over a few times have been good alignment tools for how I do it.

[Chaky]

Guys I would need your help on sensor issue... I've put 41F sensors insted the old ones (they are the same type) , but still get  e hall error. When measuring voltages all 3 sensors are working fine (3.3V on, 0,016V off). 

When i turn the wheel slightly (magnets change position) I receiver this error, but when I turn the wheel little faster, I still get the readings for speed which is little odd and is actually the sign that sensors are functional. 

At the moment I am so desperate that I even think if additional caps that I added could have something to do with it... 

Edited May 6, 2023 by Chaky

[techyiam]

17 minutes ago, Chaky said:

When i turn the wheel slightly (magnets change position) I receiver this error, but when I turn the wheel little faster, I still get the readings for speed which is little odd and is actually the sign that sensors are functional. 

With the latest firmware, it can run senseless above 8 or 10 km/h. 

Have you check for continuity of the hall sensor wires and connectors from sensors to controller board, including the junction box.

20 minutes ago, Chaky said:

At the moment I am so desperate that I even think if additional caps that I added could have something to do with it..

Highly doubtful since hall sensors have only to do with rotor position. 

[Chaky]

I've tested all 3 sensors  in circuit, and got mentioned readings...which means all cables/connections are OK. 

When I disconnect one sensor for example, speedometer don't respond... Connect it back and it works again.

[techyiam]

53 minutes ago, Chaky said:

I've tested all 3 sensors  in circuit, and got mentioned readings...which means all cables/connections are OK. 

Where are you probing to be confident that the wiring and connectors are fine?

54 minutes ago, Chaky said:

When I disconnect one sensor for example, speedometer don't respond... Connect it back and it works again.

Interesting test result. What speeds have you observed? 

[Chaky]

3 hours ago, techyiam said:

Where are you probing to be confident that the wiring and connectors are fine?

I've made additional cabling on connectors I so I could acces signals with the probes. 

 

Speeds were just with hand turning the wheel... 4-5kmh

[techyiam]

9 hours ago, Chaky said:

Guys I would need your help on sensor issue... I've put 41F sensors insted the old ones (they are the same type) , but still get  e hall error. When measuring voltages all 3 sensors are working fine (3.3V on, 0,016V off). 

Note that middle hall sensor is flipped over on the 2110xxxx motor.

The pinouts are: 

Pin 1  -  power

Pin 2  -  Gnd

Pin 3  -  output.

Look closely at the red wire.

Whereas, in the 2111xxxx motor, all three sensors have the same mounted orientation. All pin 3 (output) are on the same side of the sensor. Note that sufficient magnetic strength is required to reliably turn on and off the hall sensor.

Note also Denis Hagov replaced the stock hall seniors with Allegro A1220 hall sensors and got it to work.

Allegro A1220 Hall Sensors

 

Time-stamped. 

 

Edited May 6, 2023 by techyiam

[Chaky]

Thanks for the inputs! 

I went already in details through video and also checked. Pdf for allegro sensor which is actually chopper stabilized and quite different from SS41F and needs additional 0.1uF to clean up filtering. I tried TLE4935L but it also didn't work. 

Reason why mid sensors is wired differently was puzzling me also for some time, but the only reason that seems valid is too wide gap on stator plates. Sensor is trapezoid shape, so when you mount it  flipped for 180deg it would not potrude through the gap that much and not scrape on the rotor magnets. Sensor will not work if output and Vcc pin connection is swapped. 

At the end I managet to get the 41F, but they also didn't work. So my guess is that sensors are actually not the root cause. 

I went in detailed inspection agan, and noticed scraping on stator wires. Below pcb there is also same type od scraping damage. This damage is present all around the stator circumference so it would not make sense that i managed to make such damage durring handling/assemblying. Especially this dmg below the pcb is obvious evidence that this came from factory, because I never moved the pcb from it's place. 

So, the new theory is that when the current is very high, you would get some kind of current arching on the scraped wires and this would cause the error. Because I've changed the sensors, it could be that I made the clearence between the pcb sensor and the damaged wires even smaller so that smaller current going through the coils would cause arching and sensor error. I'll try to insulate the scraped wires and check if it will work :/

 

[Chaky]

Spam update:

Despair continues... 

Additional insulation on wires didn't work. Error is still the same. As soon as I move the wheel, I receive E HALL error. In all my desparacy I tried to swap Vcc and output pins on mid sensor and ofc it didn't work - speedometer is dead. 

I only have two more options in my mind - first one is stator is scraping the magnets and this is messing up the control. Second  one control board is dead.

Edited May 7, 2023 by Chaky

[techyiam]

2 hours ago, Chaky said:

Additional insulation on wires didn't work. Error is still the same. As soon as I move the wheel, I receive E HALL error. In all my desparacy I tried to swap Vcc and output pins on mid sensor and ofc it didn't work - speedometer is dead. 

How about connect with correct pinout, but flip over the middle sensor so that it is the same as the other two sensors?

2 hours ago, Chaky said:

Additional insulation on wires didn't work. Error is still the same. As soon as I move the wheel, I receive E HALL error. In all my desparacy I tried to swap Vcc and output pins on mid sensor and ofc it didn't work - speedometer is dead. 

With the latest firmware, the wheel can run hall sensor-less if the speed is above 8 or 10 km/h. 

Can you spin the wheel by hand that fast? If you can, the wheel should self-balance. 

 

Also, can you confirm that the hall sensors are of the latch type. That is, the output should be low when one magnetic pole is aligned, and the output only should go high when the other magnetic pole is aligned?

[Chaky]

Like I already said, sensors are checked and working properly. They are latching/bipolar type. 

First sensors that I have installed were of unipolar type, and maybe it could be that this messed up logic and now every time I get this error even with bipolar in place. Maybe there is some kind of "master reset" for the software? 

I really don't understand how spinning the wheel faster would get it to start self ballancing? :/

 

Question for mods... Can this content (posts related to troubleshooting) be transfered to repairs section? 

Edited May 8, 2023 by Chaky

[techyiam]

11 hours ago, Chaky said:

Like I already said, sensors are checked and working properly. They are latching/bipolar type.

Sounds like you already have gone past this stage. 

11 hours ago, Chaky said:

I really don't understand how spinning the wheel faster would get it to start self ballancing?

Did you know that the Abrams can still operate and self balance if it is running above 10 km/h, even after you have deliberately snip two of the hall sensors out while operating? Above 10 km/h, the Abrams doesn't need the hall sensors to operate.

Edited May 9, 2023 by techyiam