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GEP
10-15-2013, 02:45 PM
I have a flat rear window on my tractor cab and like to put a wiper on it. The glass is longer( higher) as it is wide, to get the maximum out of a wiper i like the wiper to go straight across. Has any one ever made a double arm wiper
Thanks

Royldean
10-15-2013, 03:00 PM
How about one with a "virtual" swing arm that replicates the pat of a much longer arm (done with linkages)? It will give you a swath that is closer to rectangular in shape (as apposed to a "sector" that is created by a single arm).

The Artful Bodger
10-15-2013, 03:05 PM
You mean like a pantograph wiper? I think they are common on buses and no doubt trucks.

Here is an example being offered for marine use
http://www.absolutemarine.co.nz/images/products/Wipers/4610.jpg

http://www.absolutemarine.co.nz/products/index_dynamic.php/product/6435

One of the problems with them is that as they wear a little and joints become slack the wiper blade becomes laid over one way and does not wipe properly on the return.

Mike Burch
10-15-2013, 04:17 PM
My own solution to that problem with my digger was simple - don't work in the rain.

Cuttings
10-15-2013, 05:25 PM
They use them a lot on large yachts. A couple of things to keep in mind.
Make sure the motor is powerful enough to swing the length of wiper arm you end up with.
I have seen wiper motors burn out just because they put a longer blade on than it was designed for.
Extending the arm will have the same effect. The marine parallelogram arms are made to be adjustable for length and
the good quality motors are adjustable for different angles of sweep.
When you increase the length for a long window you sometimes have to decrease the sweep angle to keep the wiper on the glass.

GEP
10-15-2013, 05:39 PM
Yes Artfull
That is what i need. My problem all the ones offred are to long

GEP
10-15-2013, 05:43 PM
Larry
What i need according to my measurements. The arm needs to be 12-14 inches The blade the same lenght

Cuttings
10-15-2013, 06:07 PM
I just had a look in a marine catalog I still have kicking around.
Ongaro makes a parallel arm that is adjustable from 14 to 19" and they have blades from 11 to 22".
Their heavy duty two speed wiper motor has adjustable sweep.
I'm no longer in the business - retired, but could dig you up some part numbers to look for if you like.

GEP
10-15-2013, 06:55 PM
Larry
What i am trying is a rear (tailgate) wiper motor from a 1998 S10 Blazer The sweep with out the blade is fine. With the blade i go 3" beyond the wind shield. with the lower part of the blade
The blade is 12" as is the arm. I had the motor with the wind shield layed out on a 1/4 thick piece of plywood . I thought if i would use the double arm i would be able to stay on the wind shield. I was thinking if i could sweep the wind shield in horizontalel motion all would work fine. The motor has no sweep adjustment that i can see. I had the cover of the gear box. On the motor is a worm that drives a gear. On the gear is a arm that connects to the hub the wiper arm fastens to.

boslab
10-16-2013, 12:49 AM
I have a little 3 ton digger, i treated the glass with rainX, it doesn't cure the problem but visibility is much better in the wet, the rain just beads up and if i set the engine revs just right the vibration of the windows shakes the water off, wonder if anyone makes a window vibrator!, quick patent it!
i did make a rotary wiper for a ship once, it did have the disadvantage that the motor was in the middle of the window, that drove a circular polycarbonate disk that span the water off, no rubber to change and ice wasn't a problem.
Mark

GEP
10-16-2013, 06:04 AM
boslab
The motor on my wind shield will be in the center top. Cant mount it on the side frame its not wide enough only have 1 1/2". I am interested in the polycarbon
disk consept. Can you expand and give me more info how you constructed it, how do you think it would work with snow wet snow?

The Artful Bodger
10-16-2013, 06:10 AM
Hi, the rotating disk is known in the marine world as a "clear view screen". The concept is quite simple although it may be more difficult to actually make one!

You just need a polycarbonate or glass disk which is mounted in front of the windscreen and is rotated by a motor at a few hundred RPM. Any rain, snow, sleet etc that falls on the disk is immediately flung off.

GKman
10-16-2013, 06:50 AM
Search for four bar linkage. Your problem will then be too many solutions.

GEP
10-16-2013, 07:09 AM
Artful a wiper motor does not rotate to fast. You are saying a few hundred rpm. I have to use a different type of motor to get higher rpm. What do you recommend

Cuttings
10-16-2013, 12:48 PM
It sounds like you are almost there. If the center of the blade you have does not go past the edge of the window a parallelogram arm will do the trick.
Exalto, another marine manufacturer makes an adjustable parallelogram arm from 270 to 450mm = 10 5/8 - 17 11/16".
I cannot tell from the picture if these use the standard spline type drive hub on the motor.
You could possibly make one with a second arm and a bar across 2 pivot points at the bottom end to mount your blade.
You also have to make a pivot mount for the second arm next to the point where the motor shaft comes out.
There is mention here of a spinner type window used on some high end yacht, tugs & ferries.
I would not try to use one of these in a dirty environment. They work very well with just clean water landing on them.
If you tried to make one the tricky part would be the seal between the rotating part and rest of the window which is stationary.

GEP
10-16-2013, 02:23 PM
Larry
The 2nd arm just turns on a shaft the arn appears to have a bushing in it . I am in the prosses of making the arms and the mounting now. I was just
woundering how far to keep the 2 arms appart any idea ? On the pic i have taken from online sellers it dont seam to be to far, dont look like the center is over 2" the bottom pivot connection (blade end) look to be in the center of the blade. Does it have to be

The Artful Bodger
10-16-2013, 02:26 PM
Artful a wiper motor does not rotate to fast. You are saying a few hundred rpm. I have to use a different type of motor to get higher rpm. What do you recommend

If you are wanting to try the spinning disk system I suggest a suitable motor would be one from an electric radiator fan.

Cuttings
10-16-2013, 04:17 PM
It really doesn't matter as long as the the arms are parallel. Whatever is convenient, 1 1/2 - 2" is good.
remember you have to be able to see past & through them.

daGrouch
10-16-2013, 07:29 PM
Hi, the rotating disk is known in the marine world as a "clear view screen". The concept is quite simple although it may be more difficult to actually make one!

You just need a polycarbonate or glass disk which is mounted in front of the windscreen and is rotated by a motor at a few hundred RPM. Any rain, snow, sleet etc that falls on the disk is immediately flung off.

Always wondered what those things were when I saw them on Deadliest Catch.

Thanks :P

GEP
10-16-2013, 07:31 PM
Thank you all for your help and ideas. I bean making parts just finished milling the ends. Tomorrow i will start putting all the parts together. I will post pic when i am finished
Thanks again