How to extend wiper shaft?

[prodigy]

As the topic title says, how do you people extend the shaft? (see attached photo)

Last year when I did my first setup with wipers, I've welded the lever/arm directly on that small piece of shaft, the wipers were old so I didn't care much about them, but it did work fine. These what I have now are new ones and I need to extended the shaft first for about 7 cm, than attach the lever/arm on it.

What type of screws to use to make it tight, to prevent it from 'unscrewing' once they start to work / rotate?

[yokoyoko]

Perhaps you could extend the shaft with some DIN 6334 M8 Nuts and screw some M8 threaded rods in?
http://www.ebay.de/itm/5-Edelstahl-V2A-Lang-Muttern-DIN-6334-M8-x-30mm-/190407356952

For securing - Loctite 270 has a break loose torque of 33NM and if that isn't enough Loctite 276 has 66NM.

But keep in mind that with such a long lever arm the force on your wiper-gearbox bearings will become higher.


Best regards
yoko

[Tombo]

Hi i did it like floriske did in his post have a look here http://www.x-sim.de/forum/gallery/image.php?image_id=125
http://x-sim.de/forum/viewtopic.php?f=36&t=617
with a second bearing to reduce force to wipermotor gearbox.

[prodigy]

Thanks for the answers people.

@Yokoyoko - I've went and bought those stuff you suggested, I've found same Loctite 270 and some M8 nuts, but 2.4 cm long.
I've maybe overcalculate myself, I only need about 3 cm longer shaft, those nuts you suggested would be perfect but this store didn't have those.
Nevertheless, I think this would help.
I see that you have attached lever arm directly on the shaft, but from your photos I don't see what type of screw nuts did you use.
How did you make it tight?

@Tombo - That's interesting solution too. From this photo is see two small screws drilled through this long nut. So I would need to drill through wiper shaft too? one hole through the shaft, one through the threaded rod that goes in the long nut?

[Tombo]

Hi,
i drilled the hole only in one side of the nut. I used a 2,5mm drill and cut a m3 thread into it. If you screw it tight to the motor and fic the little m3 screws with locktide they never will get unscrewed.

[yokoyoko]

Hi prodigy,

,

I don't use a srew nut (only kind of). I use the original lever arm available for this wiper (con: only 4,5cm long) this got a concentric bore with ~18°. You can see this on your first photo in the red circle. It is a "crimp connection". For securing I use a gearwheel where i put in a M8 thread. This gearwheel I need for my potentiometer. Just some loctite and screw it by hand hand holds thight enough.

May be for your solution a force fitted (friction locked) connection with a srew into the long nut would be fine?. You will have to test. Otherwise I would test one or two welding spots between a srew and your lever arm and put this with some loctite into the nut. You will just have to make sure not to weld too big spots so you cant get a wrench on the the screw for fitting.

[prodigy]

Unfortunatelly, alone Loctite 270 didn't help much. The nut got loose at first start of the motor, it didn't got loose all the way, only small part of the screw, but that was enough that it didn't worked like it should.

At the end I added two small welding points and that worked like a charm. Very tight, lever rotating without loose space, no problems

[yokoyoko]

Nice that you found a solution! sometimes try and error brings the best working results ^^

Can you show us a picture of the current lever mounting to the motor?

[wptm]

I've also welded there two small metal spots. It's enough to hold it, and actually it can be removed also. I did remove it once with a file.
I was looking a lot for a threaded thing which has the same conical grooved chamfer. But did not found.