Simrad WP30 Belt Tension

[SabreToothedEngineer]

I have a Simrad WP30 on my 1983 Hunter 34. I believe it's original, but I'm not sure.

There was an episode about two or three years ago where it started losing its sense of direction. It would be working okay, then suddenly decide it wanted to wander off as much as 45° off course. At the time, one contributor described it as doing a Crazy Ivan. I discovered the belt was damaged and replaced it, and for the time since then it has been okay. Just recently, it started doing it again. This time, the belt looks perfect. The drum that the belt runs on is shiny smooth, however, and there is very little friction with it engaged (I can easily turn the wheel). The tension is at the maximum.

I see in an older thread where someone commented that the screws holding the motor can come loose, and at the next opportunity I'll check that (I just read that when I got home today). In the meantime, if I wanted to increase the friction on the drum, does anyone have any advice on how to do that? I've roughened it slightly with sandpaper that seems to have increased the grip, but not really enough (I haven't taken the boat out yet to see if it works better or not). Would belt dressing possibly increase the grip enough? Is there a way to increase the tension beyond what the adjusting screw allows?

Any advice appreciated. Replacing the whole thing would be an expensive proposition that I'd rather avoid.

 

[Richard19068]

The belt might look perfect but could be stretched. I would probably first try replacing it with a new one and see if that helps.

I don't know how to increase the tension other than by the adjusting screw but I would be leery of belt dressing because the belt does need to slip when the pilot is disengaged and I wouldn't want to have it sticky while manual steering. I have done a light sanding of mine as you have and that helped a bit.

FWIW on my unit the adjustment screw works opposite of the way the manual says to turn it to increase or decrease tension.

I get very frustrated with mine. It's 18 or19 years old but i've tried to keep it together. At one point the "V-Groove" became partially detached from the drive ring and I had to glue that back on and also had to build up some areas the V Groove that were wearing through.

I've got a few PDF manuals and drawings. If you want copies let me know.

Please let me know what works for you.

 

[Brian D]

Is the belt you have on there the correct belt? I don't know what the WP30 uses, but I am sure it is the same belt as the WP32. The Simrad WP32 use an AT5-825-10 belt. Do you remember when car fan belts would squeak? We would use a bar of dry soap to increase the traction. Or, a can of Squeak Stop.

 

[Richard19068]

Do you remember when car fan belts would squeak?

Ha.Like mine a few weeks ago on the 1985 Volvo wagon.

Is the belt you have on there the correct belt? I don't know what the WP30 uses, but I am sure it is the same belt as the WP32. The Simrad WP32 use an AT5-825-10 belt.

My WP-30 uses that same belt.

 

[SabreToothedEngineer]

That is the correct belt, and I (1) compared it with a brand new one and the length is exactly the same, and (2) installed the new one, not the old one - same result. It's not the belt this time.

 

[SabreToothedEngineer]

The belt might look perfect but could be stretched. I would probably first try replacing it with a new one and see if that helps.

I don't know how to increase the tension other than by the adjusting screw but I would be leery of belt dressing because the belt does need to slip when the pilot is disengaged and I wouldn't want to have it sticky while manual steering. I have done a light sanding of mine as you have and that helped a bit.

FWIW on my unit the adjustment screw works opposite of the way the manual says to turn it to increase or decrease tension.

I get very frustrated with mine. It's 18 or19 years old but i've tried to keep it together. At one point the "V-Groove" became partially detached from the drive ring and I had to glue that back on and also had to build up some areas the V Groove that were wearing through.

I've got a few PDF manuals and drawings. If you want copies let me know.

Please let me know what works for you.

The adjustment screw on mine works as described in the manual (which I have). I tested this by turning it the other way, at which point there is zero friction whatsoever. With it set for maximum tension, it's now sticky but I can still turn the wheel, which I don't think I ought to be able to do.

I'm wondering now if the tension is loose because the V-groove is worn, and if so, if there is anything I could do about that. Maybe build it up with a layer of epoxy? Hmm. I'd want to be careful that nothing would break free and jam things up. That could cause a bit of excitement out on the water. Another thought is maybe I could increase the diameter of one of the idler pulleys slightly; that would probably be easier. I could probably even fabricate a new pulley fairly easily.

 

[Brian D]

If you can turn the wheel when the clutch is engaged, I don't think it is the belt, it sounds like it is the clutch. On my WP32 I cannot turn the wheel once the clutch is engaged. Well, I can but then I will be forcing it which is NOT GOOD at all.

I am sure you already did this, but if not, check the clutch again while the wheel is engaged and you are at the dock.

 

[Richard19068]

That is the correct belt, and I (1) compared it with a brand new one and the length is exactly the same, and (2) installed the new one, not the old one - same result. It's not the belt this time.

Why can't it ever be the easy thing?

With it set for maximum tension, it's now sticky but I can still turn the wheel, which I don't think I ought to be able to do.

I agree.

I'm wondering now if the tension is loose because the V-groove is worn, and if so, if there is anything I could do about that. Maybe build it up with a layer of epoxy?

That's possible. As I said the V-Groove on mine was partially detached and in parts worn to the point of splitting. I glued it back together and built up portions of the groove a bit about two years ago with a product called E6000. So far it is still holding together and working.

Another thought is maybe I could increase the diameter of one of the idler pulleys slightly; that would probably be easier. I could probably even fabricate a new pulley fairly easily.

I suppose that's a possibility but I can't imagine it's the source of your problem.

Good luck, and again, please post whatever solution works for you.

 

[SabreToothedEngineer]

I took it completely apart again and discovered a couple of things. Most importantly, the two nylon slides in the clutch assembly were worn, the upper one significantly. In both cases, however, the wear was all on one side. I swapped them, putting the unworn sides where the worn ones were, and voilà, we have tension!

Assuming I don't wreck the whole thing attempting to repair the V-groove (see below), I'm going to order replacement slides. I found a company who sells most of the wear parts for the WP10, WP30, and WP32. I'm not sure about the rules here about posting company names so I won't unless someone tells me that's okay. In the meantime, if you Google "Simrad Navico WP30 replacement parts" you should find it easily enough.

Second, as Richard said, on inspection the V-groove is worn, actually completely through in one spot. There is a seam in it (i.e. the plastic doesn't make a complete circle; it has a break in it), but I think that's the way it was made. The edges are too square and uniform to be a crack. One side of that is loose, too, and pulled out when I pulled it off the rollers. I don't think it being loose over part of the arc is an issue, but the wear almost certainly is.

I'm going to look into this E6000 product Richard mentioned. I'm thinking to put some goop in the groove, make a plastic spatula the shape of the groove I want to end up with, and use that to form a new groove. I'll figure out the depth and shape by measuring the existing rollers and the ring. Hopefully I can end up with a smooth groove of the right dimensions.

It would sure simplify things if you could just buy a replacement V-groove ring...

If all goes well, it'll be like new!

 

[SabreToothedEngineer]

Does anyone know, or have a good guess about, what the material that V-groove ring is made of? I'd like to choose an epoxy that will roughly match the hardness and will bond to it.

 

[Richard19068]

Good info. Thanks for sharing.
I thinks it okay to post the name of a supplier. Are the slides you are referring to the "clutch shoes" sold by i3D Gear?

I'm thinking to put some goop in the groove, make a plastic spatula the shape of the groove I want to end up with, and use that to form a new groove. I'll figure out the depth and shape by measuring the existing rollers and the ring. Hopefully I can end up with a smooth groove of the right dimensions.

That's pretty much what I did but as your name implies you are probably a bit more of an engineer than I am.

There is the same "seam" in the V-groove on my AP. I agree with your thinking that is the way it's made. I imaging it's just a flat strip that they lay into the drive ring and glue down.

I don't know what the V-grove is made of but the E6000 has held it so far. Since doing that repair / rebuild of the groove I was thinking West Systems G/flex 655 Thickened epoxy might possibly be a better material. The guy at i3DGear seems to have a pretty good knowledge of materials. Maybe you can ask him. I see he is more or less in your neck of the woods.
I wonder if he could reproduce the V-groove?
p.s. I now see there is a product called E6100 which is thickened E6000. That would have been better to work with than the thinner E6000.

At the risk of a litle thread drift, what's your favorite brewery in the Deep Bay area? I may be driving up through the east coast of the island sometime in June.

 

[SabreToothedEngineer]

First, yes, it is i3DGear I was referring to, and I had no idea they were right here! Saltspring is an hour and a half drive and a 15 minute ferry from here. I just assumed they were in the U.S. I will definitely give them a call to ask if they can make that ring.

Second, guilty as charged - I'm a semi-retired mechanical engineer. It permeates every aspect of my life.

Finally, Deep Bay contains a marina (actually two, one public and one private), a very nice little restaurant, and a university marine research centre. Pretty much exactly nothing else. However, if you're running up the coast there are a several brew pubs along the way, notably Arrowsmith Brewery in Parksville and White Sails in Nanaimo. Pretty much every pub along the way will have local beer, however. Phillips Brewery out of Victoria makes Blue Buck which is really good, and which you'll find at roughly 100% of the pubs on the Island. One place we really like, although it's not a brew pub, is the Shady Rest in Qualicum Beach. There is a restaurant side and a pub side, but they have the same menu. The restaurant side is a bit classier but it's still really rustic, and the pub side is slightly rougher but far from being a dive. It's in one of the oldest buildings on the Island north of Victoria (at a whopping 90-some years old).

 

[Richard19068]

Thanks for the tips.

We've been to Phillips a few years ago. I remember they had a killer Grapefruit IPA.

Sounds like Shady Rest is a good place to check out.

 

[SabreToothedEngineer]

So I'm a very happy guy right now. I sent an email to i3DGear, shut my computer down and within two minutes my phone went off. It was Rick Wallace from i3DGear, who said that he'd love to make that ring because he's gotten a couple of dozen requests for it in the past, but he needs an original to measure up. As it happens, we're heading to Europe in a couple of weeks for three weeks, so I'm sending him the whole assembly to measure. Since I'm so close it's trivial to pack it up and send it, and I'll have it back before well we need the boat again - if I go out in the next two weeks I can manage without it as it'll only be a day trip or two. I'm also sending him the metal bracket from the clutch so he can measure that too. With all that he'll now be able to manufacture every single wear part on those autopilots. So for anyone else with similar problems, he's now the go-to guy!

 

[Richard19068]

That's great. It will be good to have a source for replacements.

It will be interesting to see if he has any opinions about adhesive for the ring.

Thanks

 

[SabreToothedEngineer]

He's planning to make the replacement out of Teflon, which, of course, nothing sticks to. We'll probably need to talk more about this, but I'm thinking that if we put lots of grooves or holes in the backside to act as keys we can stop it from rotating, which is all we really need to do. Alternatively I can ask if he can make it from HDPE or something similar that we can actually get an adhesive to stick to.

 

[SabreToothedEngineer]

Correction: he's not going to make the ring out of Teflon. I misread one of his emails. Adhesion is not going to be an issue, as the material he's going to use is easy to glue.

 

[SabreToothedEngineer]

Update: Rick Wallace from i3DGear has designed a new ring in three arc segments and a way to press it in place while the epoxy sets. I think I've helped at least a little with the design. It looks really slick.

The original ring was very thin at the bottom of the groove. Rick is going to make the ring with a slightly different groove, making the ring much stronger and giving more bearing area for the rollers. The original roller was made of ABS, which he thinks was a relatively poor choice for a wear part. The new one will be considerably stronger and better wearing. Since the groove is different, we'll need to make new matching rollers. In the end there will be a replacement kit with the ring pieces, an installation tool, new rollers, and the adhesive to install it. He's making a video to show how to install it.

There is no doubt in my mind that this ring was the cause of the issues I've had. When one of the V-rollers was aligned with the worn spot it would allow the ring to move slightly off center, decreasing the tension on the belt and allowing it to slip. Being able to replace this ring will be a big help to anyone with this unit. I'm heading to Europe for three weeks next weekend, and will install the prototype when I get home to test it and confirm everything fits and works properly.

He's also designed (and already made) a replacement for the clutch plate. Mine isn't too worn, but he has a customer in Sweden who needs one.

 

[Richard19068]

Good news. Thanks.
Please let us know how it works out for you. I might order a set.

When one of the V-rollers was aligned with the worn spot it would allow the ring to move slightly off center, decreasing the tension on the belt and allowing it to slip.

That makes sense and would explain the symptoms I have had. I think you've hit on the problem.

 

[i3DGear]

This is Rick from i3DGear Marine. As Brian (SabreToothedEngineer) has already pointed out, we are almost finished designing the new V groove ring and new rollers. It is made of a tough, slightly ductile, plastic - the ductility is important to increase its strength by not being brittle. This plastic is non hygroscopic - meaning it does not absorb water - important for marine parts. The installation will be quite simple using a supplied epoxy adhesive. Because of the design changes which were made to increase the strength and longevity of the new ring, it requires replacement of the 6 ring rollers - only the rollers - they are compatible with the existing ring roller sleeves (however, it should be noted that we do sell 3D printed replacements for the ring roller sleeves as well as almost every other component for this autopilot model including all the clutch parts - shoes, rollers, metal plate, and all the nuts/bolts/sleeve bearings). We anticipate this being ready and tested within a few weeks. Please let me know if you are interested in one of these or go to our website and respond.

Cheers,
Rick
i3DGear Marine