AlanT Posted August 7, 2015 Report Share Posted August 7, 2015 I'm making up Lucas B90 exchange-plan wiper-motors that have never been used at the moment. These come without any big gear wheel fitted. I have quite a few 150 degree wheels because they were used in much more common saloon models. Some time back I made a jig to reset the crank-pin to 120 degrees and this is the result: https://flic.kr/p/vK7rYV The jig also makes 115 degree wheels. Now why would I want to do that? Well its the sweep angle for a TR6. I guess that the factory found that 120 degrees is almost too big for a TR4/4A windscreen. Especially if you have some wear. Does anyone find this is the case? Quote Link to post Share on other sites
peejay4A Posted August 7, 2015 Report Share Posted August 7, 2015 Hi Al My 4A has a 120 degree gear and with all new or NOS parts the sweep is just right. There's not much scope for wear before the blades begin contacting the screen rubber though. I guess there'd be even less room for wear if the wiper blades were over sized. P Quote Link to post Share on other sites
AlanT Posted August 7, 2015 Author Report Share Posted August 7, 2015 I swapped a forumite a 120 wheel because he had a 110 and his wife moaned she couldn't see out. I may make a 115 out of the next one to see what happens. Quote Link to post Share on other sites
peejay4A Posted August 7, 2015 Report Share Posted August 7, 2015 I would think that 115 would be useful. Quote Link to post Share on other sites
AlanT Posted August 7, 2015 Author Report Share Posted August 7, 2015 Thanks Pete for the encouragement. I can similarly make 125 for the motors that use 130 degree. Here is my jig: https://flic.kr/p/nCZKHK I was lucky to get a few 120 wheels that are NOS and still have the clips and springs and bits with them. Most helpful. Let's see if anyone else can see the relevance of this! Quote Link to post Share on other sites
Motorsport Mickey Posted August 7, 2015 Report Share Posted August 7, 2015 If there's a 115 deg spare Alan I'd be well pleased to take it off your hands, PM me a price if you wish to sell one. regards Mick Richards Quote Link to post Share on other sites
AlanT Posted August 7, 2015 Author Report Share Posted August 7, 2015 I haven't made one yet. I'll knock one up for you. Do you have one I can alter? Quote Link to post Share on other sites
graeme Posted August 7, 2015 Report Share Posted August 7, 2015 Alan, My Tr4A has a 120 and the wipers hit the rubber surround, so I can see the benefit of a 115 deg and would be interested in buying one. Cheers Graeme Quote Link to post Share on other sites
BlueTR3A-5EKT Posted August 8, 2015 Report Share Posted August 8, 2015 TR2-3B Solved my 'wiper blade lower edge hitting the screen frame' issue by fitting the correct length wiper blades. nominal 8" rather than 9" Micho car Are you sure you have the 10" rather than 11" blades fitted? Peter W Quote Link to post Share on other sites
tim hunt Posted August 8, 2015 Report Share Posted August 8, 2015 I would also be interested in a 115 deg sweep gear. My 4A has the standard 120 and even with minimised lost motion after a thorough overhaul of the motor, a new rack and new wheel boxes the standard length blades still contact the screen rubber at both extremes. Tim Quote Link to post Share on other sites
AlanT Posted August 8, 2015 Author Report Share Posted August 8, 2015 (edited) Ah much as I thought. 120 is actually just a bit too much. You can see the problem with the wipers when you work out where to put the crankpin. The difference between a 120 wheel and a 130 wheel is about 1mm in the radial displacement of the crankpin from the axis. So a 115 wheel has the pin about 0.5mm, 20thou, nearer the centre. You can easily have 1 or 2 thou backlash in the rack, a similar amount in the wheel boxes. So if an absolutely as new original held a 120 sweep, it will quite soon be doing 125. Don't think this just a "classic" problem. My son has a 5 year old Corsa with blades that won't stay on screen. Edited August 8, 2015 by AlanT Quote Link to post Share on other sites
BlueTR3A-5EKT Posted August 8, 2015 Report Share Posted August 8, 2015 I have a NOS 115 degree gear for a TR6 wiper motor _14W Type_ Any use to anyone at a fiver plus postage.? Peter W Quote Link to post Share on other sites
mike3md Posted August 15, 2015 Report Share Posted August 15, 2015 Alan, "I swapped a forumite a 120 wheel because he had a 110 and his wife moaned she couldn't see out." My wife no longer moans! Fitted with a set of PIAA blades and an intermittent wipe module they have been very good in all sorts of conditions over 10,000 miles Mike Quote Link to post Share on other sites
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