Anyone have a calibrated magnetic compass on a naked Tonti? UPDATED.

[Moto]

Has anyone successfully installed and calibrated a magnetic (and non-digital) compass on an old Tonti that doesn't have a fairing?

I'd like to do just that. I installed one like this



http://www.amazon.com/Bell-Automotive-22-1-24000-8-Traveler-Compass/dp/B000FW2MCM

in the fairing of my old '83 Yamaha Vision, and successfully calibrated it with the built-in compensators. By success, I mean that it worked pretty well, so that it was off by less than a sixteenth of the dial everywhere (maybe an eighth).

But trying to put one on my unfaired T3 has been unsuccessful. A magnetometer (app, in my phone) goes nuts around the handlebar area, even with the engine turned off. I vaguely recall having tried and failed to calibrate the same model of compass on it some time back.

Any suggested solutions?

Please don't suggest a GPS; I have one I don't want to use! Please don't tell me you're happy with an uncompensated compass you strapped around your handlebars or keep in your pocket; I wouldn't be! And please don't turn this thread into another pointless GPS vs. maps-and-a-compass debate! 

Thanks,

Moto

[oldbike54]

 

 Dusty

[Guzzistajohn]

Nope on the compass but I know some stuff about the Yamaha fairing

[charlie b]

When you installed it in the Yam fairing was it located a distance from any significant amount of steel?  That may be the difference.

It is very difficult to calibrate a magnetic compass when it is mounted on a lump of steel.  If you can move it even a few inches away you'll have better luck.

PS no, I have not tried to mount a mag compass like that in decades.  Learned land nav in the hatch of a 60 ton tank so did most of that without a compass.

[Moto]

Nope on the compass but I know some stuff about the Yamaha fairing...

I'd like to know more about your installation! I've got a spare Vision fairing I've been wanting to mount on my T3, though I'd want to be able to remove it easily. (That's probably going to be the permanent deal-breaker.) Maybe another thread would be appropriate.

When you installed it in the Yam fairing was it located a distance from any significant amount of steel?  That may be the difference.

It is very difficult to calibrate a magnetic compass when it is mounted on a lump of steel.  If you can move it even a few inches away you'll have better luck.

That's what I was trying to imply, I guess. I recognize the problem and mounted the Vision's compass as far from steel as I could. Short of installing such a fairing on the T3, though, there's not much that's not steel to mount a compass on!

PS no, I have not tried to mount a mag compass like that in decades.  Learned land nav in the hatch of a 60 ton tank so did most of that without a compass.

Perhaps tank navigation methods would work better! Any ideas there?

[Wayne Orwig]

Have you thought about demagnetizing the offending metal. Maybe the handlebars.

[Chuck in Indiana]

Welded aircraft fuselages share this same problem. There is a degaussing (sp?) tool that to be used on antique televisions. A guy can make one, but I don't remember much except a bunch of copper wire and a power source. No doubt Google will tell you all about it.. but yes, you need to demagnetize the area around the compass if possible.
I didn't have any luck doing it on the Piper Colt I rebuilt, though.. and Piper apparently didn't either. They took the compass out of the panel and mounted it on the glare shield. Works ok up there.. maybe 4 inches away from the panel structure. <shrug>

[acogoff]

     I once had the unfortunate experience of trying to figure this out on a nonpaying customer's bellanca scout. It seems the gear had been recently magnafluxed after an accident and were really "magneti".  What helped was to hook the ground of an ac welder to one gear leg and clamp a piece of steel to the fartest away point of the other gear leg and strike a few arcs. Got rid of about 2/3 of the magnetism I recon. Make sure anything with diodes (alternator) in it is disconnected before attempting though. My feeling is that if the gps had been around in ancient times they never would have invented the compass.

[Moto]

Go to this web site  www.formotionproduc ts.com. and look at their black compass, its a winner, no battery's thank you!
Aerostich sells it for $65 but its cheaper ($50?) direct from them.

Thanks, Kirby. I just ordered one from Formotion for $50 plus shipping.

BTW, Formotion's web site says they are getting out of retail in general (including through distributors), so all their remaining stock is on sale. (Aerostich, Amazon, and Dennis Kirk are all out of stock on the compass.) Anyone else interested in some of their nice-looking accessories should act quickly.

I'll hope the compass works as well for me as for Kirby. My fall-back device is a sun compass I designed yesterday, but haven't built!

Thanks to all the others who replied -- helpful and on-point every one of you.

Moto

[StuCorpe]

I have used a soldering gun as a degausing coil many times. The field is much lighter than the regular coil that I have but when the coil is 50 miles away the soldering gun works fine.

[charlie b]

Perhaps tank navigation methods would work better! Any ideas there?

Yep, map and navigate by landmarks.  Good topo map for off road.  On road you need to find a GOOD map, not the usual gas station type.   AAA makes decent ones.  I also like the ones labeled "Recreation" maps for different states.

FWIW, the only time any of this has failed me is when the fog is thick enough not to see the front of my vehicle, or it is so dark out you litterally cannot see your hand in front of your face (yes, has happened to be twice).

[Moto]

I have used a soldering gun as a degausing coil many times. The field is much lighter than the regular coil that I have but when the coil is 50 miles away the soldering gun works fine.

Using the method in this youtube video?

https://www.youtube.com/watch?v=jTbkP9khh2c

[Moto]

Great Moto!

I used their mount on the handlebar which elevates it away from the bar and the bolts for the bar clamp.

I figure I'll use the aluminum clamp that came with the little black clock I just installed, as mentioned in a recent thread. (Saving the $19.95 for Formotion's clamp!)

I'm sure you know this but I will mention that when traveling, the declination (magnetic) can cause errors in the areas your riding thru. So if your heading directly into the sun mid summer and the compass is 10 degrees off you are probably in an area of high declination.

Another thing that I keep in mind is that the sun is not always due west as it sets -- in midsummer it sets north of west. This plot shows the story (for 50 some odd degrees north latitude):



This can account for the 10 degrees you mention, apart from any local changes in magnetic declination. (I came across this particular plot while researching my sun compass.)

Moto

P.S. That plot is for a so-called azimuthal sundial, and is confusing at first, so I'll explain. Use the central compass dial to read the directions of the sun at different times of day for the different months. The highest light blue line on the left part of the graph traces the bearing of the sun at 6pm (solar time) for the different months. It shows the sun is about 15 degrees north of west at 6pm in June or July at that particular latitude. How the solar time corresponds to clock time is another part of the story. The topmost of the curved lines on the left shows the bearing at sunset, which occurs at different times through the year. In June/July the sun sets almost due northwest at that latitude.

The East and West notations on the outside of the plot, on the other hand, show how the (horizontal) sundial face should be oriented.

[Farmer Dan]

Try one of these stuck on the gas tank

http://www.oreillyauto.com/site/c/detail/CA00/55558/N0344.oap?ck=Search_compass%21s%21thermometer_-1_4788&keyword=compass%21s%21thermometer

worked on my old Honda long enough to get from California to Michigan.

[Wayne Orwig]

Thanks, Kirby. I just ordered one from Formotion for $50 plus shipping.

I hope you have better luck with Formation than I did with their garbage.

[Moto]

Hey all,

I'm hoping I'll have Kirby's luck with the compass. I'll report back when I get it mounted and calibrated. I'm pretty confident in his recommendation.

If OMG has anything specific to report, that's fine. But for me the die is cast.

Moto

[Moto]

Thanks , have not seen one of those in a long time. I was thinking about the way I travel east and west mid summer, and at the mid 30's the sun is pretty much dead east and west(sun rise to sun set), It will throw some in confusion as to the compass has gone nuts..

Any way good luck, I hope you share your experience when done.

:-)

I appreciate your comment about the difference in sunset direction at different latitudes. I hadn't been thinking about that really. So I looked up a formula to make the calculation of the bearing of the sun at sunset. This formula has nothing to do with local clock time nor with longitude, so it is less complicated than calculating the bearing of the sun at, say, 6pm local time. It turns out 35 and 45 degrees north latitude both round to the same compass point, WNW, at the summer solstice. But the bearing is another point south at 25N. Here are my calculations.



Anyway, thanks again for your thoughtful comment.

Moto

[Wayne Orwig]

If OMG has anything specific to report, that's fine. But for me the die is cast.

Long story. I posted here years ago. In the end, I had purchased two clocks  and two thermometers. Not cheap. Within a year, only one thermometer was still working and Formation's answer was for me to buy another set. Their equipment failed early and the warranty is worthless.
On the other hand, I have an identical looking off brand clock and thermometer that I bought for my Centauro over 15 years ago for $15. It is still seeing daily use on my EV. No issues.

[normzone]

" Perhaps tank navigation methods would work better! Any ideas there? "

Talk about point and shoot...

[v65tt]

im fairly sure the speedo and tach have magnets in them that spin round and round ..... prob not going to help the compass..

[johnr]

Hi Moto,
I'll be interested to see how you get on with this. It is I think, likely to be hard to do with any accuracy. Not only are you trying to mount a compass on a great lump of steel, you have all manner of flying magnets and un shielded electrical currents in the near vicinity. 

When you add in localised variations due to geography, (and other traffic maybe) well, best of luck.

Of course it is successfully done on steel boats, but they almost inevitably have all things electrical shielded to the hilt and are somewhat less subject to localised magnetic anomalies than a land based vehical would be. None the less, I suspect your best chance of success would be to consult with marine compass people.

What interests me more I must admit, given that North can be readily established using an analog watch during the day and the stars by night, as long as the  sky isn't too clagged in, is why you would want to do this.

Even with a heavily overcast sky navigation can usually be successfully achieved by noting landmarks, and if the need for a compass was really felt, a circumstance that seems to me to be unlikely at best, surely a decent hand one used well away from the bike would be the most effective answer. 

So I'm curious Moto. What's the go here?

[Moto]

Hi Moto,
I'll be interested to see how you get on with this. It is I think, likely to be hard to do with any accuracy....

So I'm curious Moto. What's the go here?

Hi John,

My  motivation is all the small, winding roads we have here in western Wisconsin. I often get mixed up in my directions and find myself not knowing which way to turn at the next stop sign.

I just want to glance at a compass at a stop sign, and turn the right direction. Or I want to glance at the compass while approaching an unknown crossroad and decide whether it leads toward home (for example) and whether I should give it a try. These kinds of situations are not ones where I want to get off my bike and consult a hand compass, or even stop and roll up my sleeve.

I'll report how it works out.

Moto

[Edited for length.]

[johnr]

OK Moto, sounds reasonable and I look forward to the result. I'm probably forgetting that you live in a far more extensive land than I, or perhaps it's just the nature of your area.

You know, the yacht I used to sail (an international Dragon)out of Lyttelton (Port of Christchurch)  had had its compass removed. I bought it's owner a cheap car one for Christmas along with some other goodies I thought we should have. It would in no way be considered a steerage compass but we reckoned if we got caught out by one of the sea fogs that occurred from time to time in the area, we would have to head off shore. Afterward though at least we would be able to find the South Island.

[Moto]

I'm the OP, interested in a magnetic compass, but want to post this related product discovery before I forget to.

Marlin, a maker of motorcycle clocks, thermometers and magnetic compasses, is about to offer this gps-based motorcycle compass: http://marlinsclocks-net.3dcartstores.com/Marlins-Quest-Compass--Satellite-Driven_p_270.html



It looks pretty much like a magnetic compass, mounting on the handlebar. But it uses GPS signals to determine the vehicle's direction within an eighth of the dial: N, NE, E, SE, S, SW, W, NW, N.

I'd been wondering if such a thing had ever been made, and now here it is. I spoke to the developer today, who said it should be ready for sale next week. The case diameter is 1 3/4", and the compass requires external power, either 9v battery or 5v USB (and maybe 12v, I think). The price is about $140.

This would avoid the magnetic compensation problem entirely, and as the developer said, requires no subscription to use, unlike a cellphone. I don't know anything about its quality and reliability though. I'm sticking with my magnetic compass, and I'll post an update about that.

Just thought I'd pass this along. If anyone buys one, by all means post your experience with it.

Moto

[sturgeon]

Analogue watch and a sextant. What could go wrong? 

[sbaker]

So, have you ever seen a compass binnacle on a steel boat? With the two huge steel orbs on either side.. THAT is how you swing a compass on a ferrous metal vehicle/boat... You could attempt to do it on a Tonti frame, but you would be chasing it around trying to compensate and I don't think the compensation magnets inside most analogue compasses would have enough to offset the steel tonti frame.  The GPS compass is better it's not really a compass.. It's a direction of movement display.. Not a which way are you pointing display.

[sturgeon]

I'm the OP, interested in a magnetic compass, but want to post this related product discovery before I forget to.

Marlin, a maker of motorcycle clocks, thermometers and magnetic compasses, is about to offer this gps-based motorcycle compass...

All well and good as long as you're moving. Completely useless when stopped, unless it has a magnetic backup.

[charlie b]

The compass app on my phone works just fine when standing still.

[Moto]

OK. I've got the Formotion magnetic compass mounted, calibrated, and working well. Here is my report. [Edited for length.]

The first photo shows details of the physical mounting.



On the bottom of the compass I found a 9mm diameter brass post, tapped for a 4mm x 0.7mm screw. I used the black, aluminum handlebar mount from my recent clock purchase by drilling its existing 8mm hole to 9mm, but only half way through (lower right). I had to buy a longer screw (25mm) for the clamp-to-compass connection, but otherwise it is great, and saved the $20 that Formotion gets for their mount. (The clock with its mount was about $13, I recall.) Also visible in the picture is a little non-magnetic adjusting screwdriver I made from a dowel and brass sheet to replace the execrable and flexible aluminum version that came with the compass (seen below it).

The second photo shows the final mounting position of the calibrated compass.



Location and calibration At first I mounted the compass on the handlebar up against the clutch lever, figuring that would put it away from the "great lump of steel" I perceived near the instruments. But it was impossible to calibrate the compass -- it would only point South.

So I used my free Android gauss meter app (https://play.google.com/store/apps/details?id=com.keuwl.gaussmeter&hl=en) and took measurements. First, I measured the field strength in the middle of my yard and found it was less than 0.5 gauss, the value that the Wikipedia article indicated applies for 50 degrees N latitude. (I'm at 43 degrees.) 

Then I measured the field strength at my original mounting point near the clutch lever -- over 3.0 gauss. But another spot on the handlebar, right beside the handlebar mounting bolts, measured only about 0.4 gauss. I put the compass there and found I could easily calibrate it. (I had the motor running.)

The compensating magnets in this compass can overcome a modest field strength from the bike, but not one that is far in excess of the 0.5 gauss that the Earth is providing at its surface. I think using a gauss meter app might be a good way in general to position compasses on motorcycles. I was surprised to find such large variations in field strength at different points along the handlebar.

Performance I was able to calibrate the compass within two tick marks of each of the cardinal points (N E S W). This is within 10 degrees, good enough. I took a trip this afternoon and was very pleased -- using the sun and maps as my reference, I could see that the calibration held up on the road. The compass wanders over its heading while underway, but it settles pretty quickly so that it is not hard to interpret.

Quality of the instrument I took off the chromed brass case, hoping to see the "solid brass and stainless-steel construction for years of use" claimed on the website. The guts of the compass are made of plastic, though it seems well enough constructed. No doubt the manufacturer only meant to claim that what brass and stainless steel is present exists in the solid, rather than the liquid or gaseous states, and in that claim I can find no fault at all.

All in all I'm very satisfied. Thanks again for the recommendation, Kirby.

Moto

[Chuck in Indiana]

Nice trick using your phone Moto! I had no idea there was an ap for that..