How does the power windscreen mechanism work??

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Twin Cities, MN
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Sennister and Trike Flyer,
I am experiencing the same malfunction with the windscreen on my '04. The mention of "shims" as a temporary solution to lift the gear, to provide a new location for the cable to operate, as well as a shimming the motor(?), is very interesting. How did you achieve this and did it really work for you? What are the details and or specs of your solution? Was your solution off-the-shelf or custom built parts? Do you have any extra parts or pieces to sell? if not, where would you recommend I go to buy the parts or pieces you used. Thanks.

Looking at the worm gear and the gear housing in the pictures provided in this post (edited pics below), it appears that the gear can go no higher inside its housing (see pic with top of gear peeking out), where would any shims go? it seems moving the geared-cables, up or down might work but the pieces or shims, providing the cable's placement or spacing, are rather specific (see 2nd image identifying visible spacers or shims). Can these be cut/shaved or modified? Just curious.

For others that have had the problem and resolved it, were you able to find a new gear (parts) in stock somewhere OR is it the general consensus that the forced buying the whole $400 assembly was required?
-I can't help but wonder at times if the ST1300 was actually made in China and not Japan.
 

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sennister
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I wish I had a good answer for you. Over the winter I have been studying this issue. I have come to the conclusion that a shim won't help us. Bottom line, the design is really flawed. I have learned a few things from doing digging.

1. This design was chosen as it meant they could reuse existing hardware with some modifications. The motor is from a Honda Accord.
2. The drive gear and cable (the two problem parts) are the unique parts to this application and cannot be sourced from anywhere.

Because of this the only option is the $400 complete assembly replacement or a redesign. I started working on this but then got nailed with over $600 utility bill for the month of Jan because I was spending too much time in my shop. Because of this I have suspended all work until it gets a little warmer. This is finally happening. However I want to get my 1300 back to ridable condition so for now I pulled the damage gear. There is enough resistance in the system that I should be able to move the windscreen by hand. I have a design in mind that will replace the cable drive system. 90% of the components are available off the shelf. The 10% are going to be the problem. I have been considering what my options are for making the remaining 10% which are brackets that are needed to support the other components. The problem is that I need a mechanism for working on the design. I will (probably today or tomorrow) post a request for a damaged mechanism that someone may have laying around to use for prototyping up the mounts. Once that is done it will be a matter of ordering up the components needed.

Without going into too many details this will involve completely removing the cable drive and motor. Replacing it with a new motor that drives two threaded rods. This will be done via either a chain or timing belt style connection from the motor to the rods. The rods will sit in parallel to the tracks and have a connection to the part that slides on the track. The good news is that once the brackets are designed and made up the rest of it is pretty easy, the design will be much more robust and not have this failure ever again and the kit will be easily bolted into place using existing bolt holes in the mechanism. The drawback is that the motor is the most expensive part and will likely push the cost of the kit up to the $200 range. While the existing motor could be reused it would require lots of modifications to the motor in order to do this. While I have a metal lathe in my garage, I would be willing to bet the average rider out there that may want to do this doesn't have access to equipment like this. By not replacing the motor it ramps up the technical requirements of the conversion a lot.

Being you are local, maybe you can be one of my first test installs. I will be converting my bike and will want to work through an install a couple times before making things available here. The question is, can you wait long enough for me to work out the plan? I don't want to throw out a timeline yet. The fact that mine is broken means that I have motivation to get it fixed though.

Here is a link where I was talking about some of this....

Link

As I said the big hurdle will be making the brackets. Right now I am thinking I may try and mold them out of an epoxy, fiberglass, carbon fiber. Something along that route. The complexity of the shape would mean they would be really labor intensive to machine from aluminum or steel. Carbon Fiber or Fiberglass should be plenty strong to support the new mechanism.

I wish I had better news for you. I will be posting more on this in the future.



Sennister and Trike Flyer,
I am experiencing the same malfunction with the windscreen on my '04. The mention of "shims" as a temporary solution to lift the gear, to provide a new location for the cable to operate, as well as a shimming the motor(?), is very interesting. How did you achieve this and did it really work for you? What are the details and or specs of your solution? Was your solution off-the-shelf or custom built parts? Do you have any extra parts or pieces to sell? if not, where would you recommend I go to buy the parts or pieces you used. Thanks.

Looking at the worm gear and the gear housing in the pictures provided in this post (edited pics below), it appears that the gear can go no higher inside its housing (see pic with top of gear peeking out), where would any shims go? it seems moving the geared-cables, up or down might work but the pieces or shims, providing the cable's placement or spacing, are rather specific (see 2nd image identifying visible spacers or shims). Can these be cut/shaved or modified? Just curious.

For others that have had the problem and resolved it, were you able to find a new gear (parts) in stock somewhere OR is it the general consensus that the forced buying the whole $400 assembly was required?
-I can't help but wonder at times if the ST1300 was actually made in China and not Japan.
 
Joined
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We should email Jay Leno. Maybe he would take the bad parts and use his automated reproduction equipment to master some metal stuff that we can order bulk and keep around for replacing the crappy plastic gears.
I forget what the equipment is that he uses to reproduce all the parts for those old cars but it is really impressive.

:radleak:
 
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sennister
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We should email Jay Leno. Maybe he would take the bad parts and use his automated reproduction equipment to master some metal stuff that we can order bulk and keep around for replacing the crappy plastic gears.
I forget what the equipment is that he uses to reproduce all the parts for those old cars but it is really impressive.

:radleak:
The problem isn't the plastic gears. Well the gears are not plastic at all. The gears are made out of pot metal or powdered metal as it has been called. They are not very strong. This in itself isn't the entire problem. The another part is that the lube is not very good that at cold temps it becomes the consistency of wax. Then there is the fact that the cable is threaded through a full 360 deg of bends in the tubing. Another ding against the design. Don't forget that the cable is made out of a material that can't take the resistance and also strips. So you see there are lots of factors involved. They revolve mainly around a poor design from the beginning. This is why it might be possible to replace the components but you are still using a flawed design. By getting rid of the cable drive and going with something more robust it will last a lot longer.
 
Joined
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167
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Twin Cities, MN
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FJR1300
Sennister,

Thank you for responding so quickly. I appreciate your innovative ideas and I am interested in assisting you toward your end. [rant, incoming] The season is fast approaching here and I'm torn; I want to replace it right now but the thought of being forced to buy an expensive, whole new windscreen adjuster assembly due to the incompetence of the design engineers or the even more irresponsible decision makers by Honda leadership, turns my stomach. The mechanism in place now is a hidden serious design flaw and Honda passed it along to it's customers and seemingly continues to do so (sigh). Regardless, I own it now and have to deal with it.

Though I share your desire to seek out an alternative solution, I understand that I may end up having to buy new. Please PM me and we'll exchange contact information and discuss how best to proceed and determine if I can even help you or not. Thanks for the offer. If there's any good to be had here, it's that I may get the opportunity to meet a fellow ST-owning compadre'. :pie1: :beer3:
 
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sennister
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I too am in the same boat. I pondered buying a new one and then doing a redesign of my old one. Once I repair the old one I would pull the new one I bought and sell it on eBay or here to try and recoup as much money as I could. The new one isn't a different design so it is just going to fail again. In the end since I don't want $400 tied up in the part and would likely loose out on resale even more, I am hoping that I can find a damaged one that I can borrow for a while or use for R&D. The brackets are the hard part and since these are using existing holes no damage would come of it. Not until I physically mount the new mechanism. I would likely do that to my failed unit though unless the donor wanted to be in on a prototype initial run. Then I would send him or her the competed assembly once modified. If it is deemed to difficult to make the brackets I could return the assembly unharmed. I mainly need it for measurements and test fitting when I have to machine the threaded rod.

Sennister,

Thank you for responding so quickly. I appreciate your innovative ideas and I am interested in assisting you toward your end. [rant, incoming] The season is fast approaching here and I'm torn; I want to replace it right now but the thought of being forced to buy an expensive, whole new windscreen adjuster assembly due to the incompetence of the design engineers or the even more irresponsible decision makers by Honda leadership, turns my stomach. The mechanism in place now is a hidden serious design flaw and Honda passed it along to it's customers and seemingly continues to do so (sigh). Regardless, I own it now and have to deal with it.

Though I share your desire to seek out an alternative solution, I understand that I may end up having to buy new. Please PM me and we'll exchange contact information and discuss how best to proceed and determine if I can even help you or not. Thanks for the offer. If there's any good to be had here, it's that I may get the opportunity to meet a fellow ST-owning compadre'. :pie1: :beer3:
 
Joined
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167
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FJR1300
Sennister,
Knowing that you've had a spare mechanism to work on, if only for a short while, I am wondering if you've managed to engineer your ideas into a working prototype? I know there are many of us out here that have taken a keen interest in your work. I wish there was something more I could offer, other than anticipation.
Thank you in any case.
 
Joined
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Rindge, NH
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2006 ST1300
I was a machinist years ago, spent 10 years making, repairing, and re-engineering components for gauging & tooling at a large bearing manufacturer. Looking at the photos, while I think you are on the right track to the "why" they are wearing, I think there is more to it. I think besides the material choices, I think it was a bad design which puts excessive wear on the components. To start with, a large diameter gear is attempting to move a much smaller "gear". Doing this puts a lot of strain on the large gear. If the gear were half the diameter, it would take much less force to drive the cable. But doing that would result in less tooth contact, so would put more stress on individual teeth...so I think the choice of diameters was a trade off of those two problems.

Going along with the design flaw of the gear, look at this example of a worm gear:
http://science.howstuffworks.com/transport/engines-equipment/gear5.htm
The description also explains it- using the small gear to turn the large gear works well and provides gear reduction and a smooth action. But if you try to move the small gear by turning the large gear, it won't work well. The description of the worm drive on that site explains this a little. Honda tried to use that inefficient operation to their advantage, to actually push the small "gear" (in our case, cable) rather than turn it. They are also doing it with TWO "small gears" (cables). Its still a very inefficient design. Add that inefficiency to what has already been shown- that the gear is a poor material, had little (and poor quality) lube, and other factors- and it had no chance of lasting. Looking at the design, I don't think a major improvement could be made even if the components used high quality materials and were cleaned and lubed regularly. I think the windshields that happen to last longer are the ones that are rarely adjusted.

Looking at the photos of the entire setup, I think the best way to go wouldn't be to try to repair or slightly improve Honda's gear drive, but to eliminate it completely and replace it with a better design. I think someone was on the right track by using a linear actuator. They are extremely strong, very reliable, and well designed. For those who don't know how they work, look at a bolt and a nut. Turn the bolt, and the nut moves down the bolt. Turn the bolt the other direction, and the nut comes back. A linear actuator works the same way. They have a threaded center rod which is turned by a motor, and a mating component which is threaded, and moves in and out as the inner rod turns. Very simple, strong, and reliable. They are used in automated machinery and have a low failure rate.

The hardest part would be to connect the actuator with the cables. I really don't like the looks of Honda's cables. I don't have one of these out of a bike to pull apart. I'm curious how the cables attach to the windshield slides. It may be possible to use new cables to operate the existing slides. If this is the case, it would solve two things- a way to attach the linear actuator to the windshield, as well as allowing longer cables to be used, which would allow the linear actuator to be relocated in a more convenient location, where there is more room.

I may pull mine apart one day to clean and lube it, and take the opportunity to look at how the cables attach at the windshield end. If it looks like replacement cables could be attached, that might be a good starting point.

Jim
 
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sennister
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Sennister,
Knowing that you've had a spare mechanism to work on, if only for a short while, I am wondering if you've managed to engineer your ideas into a working prototype? I know there are many of us out here that have taken a keen interest in your work. I wish there was something more I could offer, other than anticipation.
Thank you in any case.
At this point I wish I had time to look at it more. The spare mechanism arrived but I haven't even opened the box. We had major issues at work over a month ago and Sunday was my first day off in well over a month. Any free time after work was spent trying to get the yard cleaned up from what as our worst winter in terms of trees and branches down as we had a party at our place last weekend. The one day off I have had was spend trying to get my 1300 back on the road. I managed to do the valve clearance check and swap out some shims as well as start the process of reassembly. Good news is that I was up burning the midnight oil last completing the reassembly of my 1300 so it is now off the lift and I can start on other projects. I even got to ride the 1300 to work today. Yippie!!!

Anyhow priorities of work at this moment is going still be bike maint. A member with an 1100 needs new tires, wheel bearings, brake pads and possibly a new final drive. All parts are on hand I just need to coordinate a time, probably yet this week. Then there is another member with a 1300 in need of the valve clearance check and tires. Still looking at a time on that one as we need some more items for that one before we are ready, this one is just on the radar. So I might be able to start looking at the mechanism between bikes as it won't take a lot of room. Just need to clear off some workspace on one of my benches.

As a side note, I was able to confirm a suspicion that I had in regards to the mechanism. When I put my bike back together I cleaned and lubed the drive cables. I also left the drive gear out of the mechanism. The motor is still there but no drive gear. I did this in an effort to see if I could move the screen by hand in the mean time. Sure enough it works. There is enough resistance in the system so that the screen doesn't move (tested to about 110mph) from wind but still can be pulled up or down as needed by hand. Now you can't do this while on the bike but you can do so by getting off and standing in front of it, grabbing the shield with both hands it can be moved up and down. That is another sign to the poor design of this system. It should move this hard. This isn't a perfect solution but does allow for adjustment until a permanent solution can be engineered.

I do know that there is a lot of interest in this and I will be proceeding as time allows.
 
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As always, great work Dave.

It's also great we have participants like Jim with real world machinist experience who can give us some insights into the thought behind designs. I think his was the first the lead me to understand that this was probably a hopeless project for the designer. He or She probably felt crappy at the end of the project as they battled all sorts of variables and compromises. This isn't a critical statement.they probably had no choice on cost (so they are stuck with cast worm gears and an automotive motor) and the space is limited (so they are stuck with cables.)

I'm curious to find out if the FJR, Connie and Beemer bikes with motorized windscreens have similar issues. Perhaps the solution is to figure out how a successful design works and see if it can be retrofitted to a Honda. (If you can't innovate, then reverse engineer.) :)
 
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Thanks Sennister. I do appreciate your valuable time and completely understand! Regarding your mention of a forthcoming 1300 valve check, I'd be interested in looking over your shoulder on that one, perhaps do some labor or bring some beverage (or pie even). I've got 23K miles on mine and even if I don't do the valves myself one day, I'd like to see what its all about so I can engage in some straight talk with the STealer garage and keep any unnecessary operations to a minimum. If you nail down a time on that, give me a heads-up and I'll try to cruise over and meet you guys at your shop.

nhdiesel - thanks. Very informative. STPaulK did you right in his recognition of you.

STPaulK - an interesting and worthy suggestion to look what successful competitors are doing. I think I'll go lurk about in the FJR, Connie, and Beemer forums and see if I find anything, assuming they even have such problems for them to post threads about it.

and to that point, if anyone else reading this thread has some comparo info on windscreen adjuster mechanisms in this famed line up to the ST, do tell!
 
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sennister
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Sounds good. As I said that one is a little further out on the radar at this point. I don't know if we will do tires and everything in one shot yet but he has mentioned he needs tires and that he wants to do the shim check as he doesn't know when it was done last. Really it wasn't that bad of a project. Not as bad as I was thinking it would be. Really I would say fairly easy unless you need to change some of the shims.
 
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