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PWD · 10-04-2012, 06:12 PM

Tapered shaft arms have an splined aluminum insert in them that deforms as the nut is tightened to conform to the taper of the shaft. Hold the arm firmly while you tighten the nut "wrist tight". I can't give you a torque setting . The taper does the work--think drinking glasses stuck together. Our experience is that the tapered shaft arms hold better than the hot rod straight shaft arms. Thirties vehicles were not designed to drive 70 mph and meet an 18 wheeler and many have horrendous air flow pressures over the hood. Many cars will buffet or lift the arms off the glass at speed as mentioned. It sometimes helps to kink the end of the arm ( and improves the appearance) so that the blade nestles parallel against the windshield seal in the park position. As a last resort it may be necessary to remove them and install in rainy weather. The reason that manufacturers went to cowl mount wipers is to have the air flow work in their favor instead of against them.
Even if I could build indentical motors, the airflow on one side of the glass may not be equal to the other ( cross wind) and the motors will ultimately get out of sync just like the original vacuum motors. If that bothers you I suggest running the second motor on a separate switch and using it when you have a passenger with you. I explain that carefully to everyone that orders direct.
Wiper blades do not scrape the glass they squeegee the glass. Thirties blades ( hook and saddle and earlier ) had very short, poor quality rubber with a stiff straight back that is designed to "flop over" on each sweep. Modern blades have higher quality tall rubber that does the same thing. A blade which is chattering has either hardened rubber or too much pressure on the glass. The arms we supply have the correct pressure ( 8 oz) for an 8" blade according to our "Tell-Tale" wiper arm pressure gauge. Too much pressure will potentially roll over the rubber with the metal back scraping the glass. Lifting is caused by air flow not weak springs. Adequate pressure at high speed will often be too much at low speed.
We would like to provide silent motors, however the physics of permag motors is that the smaller they are the faster they must run. The Mighty Wioer was designed to fit in the header cavity of my partner's 33 ford coupe about 28 years ago and is the smallest on the market. The motors are turning 8200rpm at alternator voltage, geared for 60 cycles/min. Noise is vibration so anything you can do to isolate the motor from the roof ( which acts like a drumhead) will help.
Larry Richards, Chief cook and bottle washer, Pacific Western Design

10-04-2012, 06:12 PM	#8
PWD Junior Member Join Date: Oct 2012 Posts: 1	Re: Mighty Wipers Tapered shaft arms have an splined aluminum insert in them that deforms as the nut is tightened to conform to the taper of the shaft. Hold the arm firmly while you tighten the nut "wrist tight". I can't give you a torque setting . The taper does the work--think drinking glasses stuck together. Our experience is that the tapered shaft arms hold better than the hot rod straight shaft arms. Thirties vehicles were not designed to drive 70 mph and meet an 18 wheeler and many have horrendous air flow pressures over the hood. Many cars will buffet or lift the arms off the glass at speed as mentioned. It sometimes helps to kink the end of the arm ( and improves the appearance) so that the blade nestles parallel against the windshield seal in the park position. As a last resort it may be necessary to remove them and install in rainy weather. The reason that manufacturers went to cowl mount wipers is to have the air flow work in their favor instead of against them. Even if I could build indentical motors, the airflow on one side of the glass may not be equal to the other ( cross wind) and the motors will ultimately get out of sync just like the original vacuum motors. If that bothers you I suggest running the second motor on a separate switch and using it when you have a passenger with you. I explain that carefully to everyone that orders direct. Wiper blades do not scrape the glass they squeegee the glass. Thirties blades ( hook and saddle and earlier ) had very short, poor quality rubber with a stiff straight back that is designed to "flop over" on each sweep. Modern blades have higher quality tall rubber that does the same thing. A blade which is chattering has either hardened rubber or too much pressure on the glass. The arms we supply have the correct pressure ( 8 oz) for an 8" blade according to our "Tell-Tale" wiper arm pressure gauge. Too much pressure will potentially roll over the rubber with the metal back scraping the glass. Lifting is caused by air flow not weak springs. Adequate pressure at high speed will often be too much at low speed. We would like to provide silent motors, however the physics of permag motors is that the smaller they are the faster they must run. The Mighty Wioer was designed to fit in the header cavity of my partner's 33 ford coupe about 28 years ago and is the smallest on the market. The motors are turning 8200rpm at alternator voltage, geared for 60 cycles/min. Noise is vibration so anything you can do to isolate the motor from the roof ( which acts like a drumhead) will help. Larry Richards, Chief cook and bottle washer, Pacific Western Design