Sherman-S 3600wh: 100V, 20", suspension, 97lb

[Rawnei]

1 hour ago, Punxatawneyjoe said:

Do you have a link to this, because there is no mention of this in the original video title.

 

"Veteran Sherman S splitting in half in the middle of riding. We think the bolts weren’t loctite from factory and eventually just came loose. Don’t forget to open up your brand new wheel and loctite all the motor bolts for safety!"

The owner and the person that crashed said it himself on telegram yesterday.

https://t.me/veteranUS

 

[Rawnei]

42 minutes ago, Planemo said:

It's certainly a weird one. You would have to be unbelievably incompetent to assemble a wheel so badly that it falls in half shortly aftetwards. Whether it was from the factory or a subsequent tyre change, it just seems inconceivable that so many fasteners could have been incorrectly installed. But..it does appear to be a genuine report. Anyone know how many fasteners keep an SS together?

You have 8 big m6 screws holding suspension to battery then 4 big m6 bolts holding battery to top shell, most likely someone forgot to torque them after the tire swap, maybe there were symptoms before this happened he just didn't notice or pay attention.

Having disassembled mine multiple times I'm not the least bit worried that something like this would happen.

[Planemo]

14 minutes ago, Rawnei said:

You have 8 big m6 screws holding suspension to battery then 4 big m6 bolts holding battery to top shell, most likely someone forgot to torque them after the tire swap, maybe there were symptoms before this happened he just didn't notice or pay attention.

Right, so a fair few fasteners, cheers. And unlike some have said, I dont buy the fact that they all need to be loctited either. So we can only assume that not only were all the fasteners just 'nipped up', or even just left loose, but I am also amazed that the rider didnt notice anything before the wheel literally fell in half. I can only imagine how wafty a wheel thats just about to separate into 2 pieces would feel, even if the rider was 'in the moment'.

I simply cant believe that 12 structural fasteners were left loose but that does indeed seem to be what happened. Staggering.

[Rawnei]

2 hours ago, Planemo said:

Right, so a fair few fasteners, cheers. And unlike some have said, I dont buy the fact that they all need to be loctited either. So we can only assume that not only were all the fasteners just 'nipped up', or even just left loose, but I am also amazed that the rider didnt notice anything before the wheel literally fell in half. I can only imagine how wafty a wheel thats just about to separate into 2 pieces would feel, even if the rider was 'in the moment'.

I simply cant believe that 12 structural fasteners were left loose but that does indeed seem to be what happened. Staggering.

They should definitly have loctite though, they're too important not to.

[Clem604]

Achieved a new personal range record today with 18% battery remaining @200lbs (90kg). 

Edited August 14, 2023 by Clem604

[Hellkitten]

42 minutes ago, Clem604 said:

Achieved a new personal range record today with 18% battery remaining @200lbs (90kg). 

Nice. So far my best is from fully charged to three bars. 🤣🤣 I rode from 5:30pm to 4:45 am with a bunch of breaks/hangouts in between. 👍👍

[Clem604]

7 minutes ago, Hellkitten said:

Nice. So far my best is from fully charged to three bars. 🤣🤣 I rode from 5:30pm to 4:45 am with a bunch of breaks/hangouts in between. 👍👍

Haha yeah that's awesome. I'm sure I could've squeezed out maybe another 5-10km's but I'm tired and need a nap 😴.

Edited August 14, 2023 by Clem604

[Planemo]

18 hours ago, Rawnei said:

They should definitly have loctite though, they're too important not to.

Its funny, I have rebuilt many car engines, suspensions and god knows what else down to every single nut and bolt yet not one of them used loctite. I dont recall using loctite anywhere on my MC's either.

Not saying we shouldnt on eucs, just saying we shouldnt have to. Insufficient thread sizes, fastener specs and materials springs to mind... 

[Poker]

6 minutes ago, Planemo said:

I dont recall using loctite anywhere on my MC's either.

 

I definitely have. A four stroke one cylinder MC have really strong vibrations, more specifically if you're gonna change oil often its nice to secure the drain bolt and the magnet bolt

[techyiam]

1 hour ago, Planemo said:

Its funny, I have rebuilt many car engines, suspensions and god knows what else down to every single nut and bolt yet not one of them used loctite. I dont recall using loctite anywhere on my MC's either.

Not saying we shouldnt on eucs, just saying we shouldnt have to. Insufficient thread sizes, fastener specs and materials springs to mind... 

Ah, so you wrench.

And if you also work on your own electric wheels, then you would also noticed that the aluminum alloys that they used in these are softer and less tough. You can not use as high a tightening torque. If you don't use a thread locker, you are taking more risk. However, if you have the experience with wrenching these wheels, you would also know what you can get away with, without the use of a thread locking compound.

[Planemo]

12 hours ago, Poker said:

I definitely have. A four stroke one cylinder MC have really strong vibrations, more specifically if you're gonna change oil often its nice to secure the drain bolt and the magnet bolt

I've had countless single cylinder 2 and 4 stroke bikes from 50cc to 660cc. I've never loctited a sump plug (which would be sacrilidge to most, especially the poor sod who does the next oil change) and only ever lock wired them on race bikes because its mandatory for race regs. But if it re-assures you to loctite, go ahead

11 hours ago, techyiam said:

Ah, so you wrench.

Indeed, most of my life. And is why I can tell when a chinesium bolt/screw is going to let go within an eighth of a turn. Which is also why I wouldnt put a power wrench anywhere near an EUC, even if it does have so-called 'torque control'.

11 hours ago, techyiam said:

the aluminum alloys that they used in these are softer and less tough.

For sure, which is exactly what I said in my previous post. I just wish that loctite wasnt the answer.

[techyiam]

33 minutes ago, Planemo said:

But if it re-assures you to loctite, go ahead

For racing, don't you have to use safety wiring?

[Planemo]

11 hours ago, techyiam said:

For racing, don't you have to use safety wiring?

Yes, thats why I said lock wire in my previous post 

[techyiam]

1 hour ago, Planemo said:

Yes, thats why I said lock wire in my previous post 

You mean the regulations stipulated both Loctite and safety wire?

[Planemo]

57 minutes ago, techyiam said:

You mean the regulations stipulated both Loctite and safety wire?

No, lockwire only. As I say, very few bolts on MC's or cars use loctite and it makes dissasembly a pain.

[smash]

Any reviews on the cyclops light yet?

[Clem604]

9 minutes ago, smash said:

Any reviews on the cyclops light yet?

Check out my impressions on the Cyclops light on Page 122

[MrMayArt]

Hi Dear Community,

I am a creator and a manufacturer of the Cyclope LED lamps for Sherman S and Patton.

I heard that some of you have an issue with too small spacers for Sherman S lamps.

In case you are using the printed bumper please feel free to print the bigger spacer which you can download here:
https://www.thingiverse.com/thing:6172386

For bigger spacers with mounted metal cover please use this model:
https://www.thingiverse.com/thing:6172390

In case of any other problems please feel free to reach me via email (mrmayart@gmail.com) or here - I am willing to help you as much as I could.

Thanks a lot for choosing my lamps.

[MrMayArt]

Additionally, I would highly advise NOT to use the stock screws (M5x25) due to their shorter lenght.
Shorter 25mm screws make worse contact with the lamp's aluminium thread and it can be easily damaged the way that lamp won't keep the vertical level anymore.

In general please be careful when mounting the lamo and try to avoid the electric screwdriver, cause it might also damage the thread.

Edited August 16, 2023 by MrMayArt

[Freeforester]

Could be that the threads have been stripped on the lamps which are not staying up? When steel meets aluminium, there tends to be a winner and a loser….

[MrMayArt]

Could be of course. But in such case you would fill it if you try to tighten the screw holding the lamp in the hand and your screwdriver would be turning without an end. In such case it means that the thread is not there anymore.
But if you tightened the screw and the lamp is still lose vertically then the spacer is a problem.

[Yaseen_digital]

On 8/1/2023 at 12:50 PM, Rawnei said:

Helicoil repair of clamp holder successful.

I used this kit: https://www.amazon.se/dp/B07H94W6K3 (M5*2D)

1. Measure the hole, 10.8mm:

2. Mark the drill with some tape to prevent drilling to long, slightly less than 9mm should be fine.

3. The length of the coil itself, slightly less than 7mm:

4. Hole drilled and re-threaded with supplied tools and ready for Helicoil insertion:

5. Screwing in the Helicoil, purple piece is stuck to Helicoil until it's all the way in which is a good indicator, keep screwing until purple piece comes loose:

6. The new M5 thread with Helicoil:

7. I did the same on the other top screw as that one was de-threaded as well, clamp successfully installed and torqued to 8Nm:

ur helicoil trick is amazing been riding mine for over 400 miles with a helicoil waiting on my replacement part to come it’s been solid used the exact same kit and instructions 👍😝

[Rawnei]

3 minutes ago, Yaseen_digital said:

ur helicoil trick is amazing been riding mine for over 400 miles with a helicoil waiting on my replacement part to come it’s been solid used the exact same kit and instructions 👍😝

Awesome, good job! Chances are the helicoil is stronger than just aluminium so you could keep the new one as spare, that's what I am doing. 😜

[Rawnei]

Anyone here knowledgeable with Active Piezo Buzzers? I have a project where I'm replacing the stock Sherman S light with a better one, the Piezo Buzzer (both the stock SFM-27 that comes with Sherman S and another waterproof active one) has some odd behaviour I'm trying to figure out. If connected in normal polarity it gives off no sound, if connected in reverse polarity it gives some sound but not as it should, like just sometimes. What am I missing, is there some other component needed?

I opened the stock Sherman S light just to take a look at the board in there where power goes through but didn't want to remove the whole board since there's thermal paste and all in there, it was difficult to figure out if there is something else on the board affecting the power delivery for the buzzer, from what I could read an active piezo should not require anything else, also I'm afraid if anything in the circuit would break from using reversed polarity.

Paging @Chriull @Planemo @RagingGrandpa and other smart dudes.

Edit: From a 12-24v DC adapter in normal polarity it sounds normal (and doesn't work with reverse polarity there) so it's just the behaviour when connected to the wheel that I can not understand.

Edited August 29, 2023 by Rawnei

[RagingGrandpa]

24 minutes ago, Rawnei said:

Active Piezo Buzzers

I think it's just DC; or perhaps PWM DC to vary the volume. 

Next step: inspect the voltage across the terminals of the original, working buzzer, during beeping, with an oscope...