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Wiper sweep - clap hands

Posted: Sun Mar 05, 2017 12:06 pm
by Tootall
Here's an odd question - can I increase the screen sweep of my clap-hands wipers.

After a 6-year layoff my Minor is (occasionally) back on the road. It passed its MOT last summer but the wipers packed up when called upon in a rain shower a little while ago.

It seems that the old grease had finally got so hard that they just ground to a halt.

I stripped the rack, spindle-boxes and motor, re-greased the lot and now I have working wipers once more.

I haven't used them in the rain yet but at the moment, with the blades starting on the rubber at the bottom of the screen, the sweep only just brings the wipers up to a vertical position, before heading back down again.

There is a cap on the top of the motor, with a concoct inside it - which I assume governs when the wipers park. Does moving the cap, and hence the contact inside, have an effect on the sweep of the wipers, or is that completely governed by the rack/spindle ratio of teeth?

To be frank, I can't really remember how much farther (if at all) the wipers used to come, so this might be a case of 'they all do that, Sir'...

Anyone got the low-down on this?

Car is a 1963 1000..

Re: Wiper sweep - clap hands

Posted: Sun Mar 05, 2017 1:03 pm
by firedrake1942
I had a similar problem when I fitted a 'new' wire motor from a scrap yard. I cheated and with the power off and wipers not parked, I moved the wiper arms on the splines so they were at their fullest and most open. I then reconnected and they parked as normal, retaining the full sweep, not that they are any good unless you are doing 60 into a force 8 gale when the blades are pushed against the screen........

jm

Re: Wiper sweep - clap hands

Posted: Sun Mar 05, 2017 6:50 pm
by simmitc
Adjusting the contact position will not affect the arc of the wipe, only where the arms park. On later cars, to adjust the arc you can either change the big gear wheel in the motor or the size of the gear in the spindle box. Finding the right spindle box can be a real problem. I'm note sure about gearing on the earlier cars.

Re: Wiper sweep - clap hands

Posted: Tue Mar 07, 2017 8:27 pm
by mike.perry
The clap hands wipers can be improved by fitting adjustable length arms and 12 inch blades. Adjust the arms so that the blades almost touch the top of the screen then move the arms on the spindles so that they are staggered and do not touch. This will reduce the unswept V in the centre of the screen

Re: Wiper sweep - clap hands

Posted: Mon Mar 13, 2017 1:42 pm
by Fingolfin
The travel arc is set by the stubby peg on the gearwheel in the motor gearbox - its distance from the center of that gearwheel determines the sweep distance.

When I fitted a two-speed wiper, I drilled through the bottom of that peg and welded it in a new position further from the center, increasing the arc. It's hard to get that precise, though, so I ended up increasing it slightly too much. :lol:

Re: Wiper sweep - clap hands

Posted: Mon Mar 13, 2017 7:45 pm
by liammonty
There is indeed an element of 'they all do that' - you'll find the travel is very much increased when travelling at any speed in the rain. Mine are as you describe to yours to be in the dry, but in the wet, sweep to the edges of the screen. I wouldn't worry too much, as you don't need to use them when it's not raining, so that reduced sweep in the dry won't matter too much!