Expedition Navigation Software 
- DuncanR
- Expert
Offline - From: Up and down East Coast Aus
- Registered: 9/16/2015
- Posts: 465
Re: B and G speed sensor misbehaving
Hmmmmm. PJ, it isn't clear to me what you are asking, maybe ask another way. Two questions/thought bubbles:
1. Assuming the log is taken out after each race - and it should be - is it put back in the same way by the same person? I don't let anybody else insert the log, the housing is a bit worn and it requires concentration and checking to ensure it is properly seated and aligned every time;
2. Do you have a heel sensor, and does your boat instrument setup allow for heel adjustments to BSP? If not, was one result fresh and the other light? That could explain the variancxe.
D
- pjl
- Expert
Offline
- From: Lake St. Clair, MI
- Registered: 11/09/2015
- Posts: 113
Re: B and G speed sensor misbehaving
DuncanR, thx for interest and reply; appreciate having other thoughts. Our log stays mounted; our biggest risk in fresh water St. Clair is a weed or a zebra mussel, but that we are alert to and can fix quickly. We know that our paddle wheel output has a delta tack to tack, and I'm hopeful that the Nexus calibration functions that show the ability to have port and starboard cals will eventually solve that problem - yet TBD when that problem gets to the top of the problem list. Yes, we have heel (roll) data on the N2K bus, but I have made no effort yet to use it. I'm still confused by the Exp cal table that I see by checking the Bsp box (settings, Exp cals, var cals, check Bsp box, click Bsp) that implies entering calibration values for up to 30k Bsp with the heel as a variable. I can see the Bsp needing calibration for heel, but why such large Bsp values? Also, why not have a port-stbd value, which seem much more relevant? Hope I have been able to clarify my quandary. pjl
- David
- Expert
Offline
- Registered: 9/23/2015
- Posts: 15
Re: B and G speed sensor misbehaving
Fergal wrote:
Duncan
Just to follow up, that document didn't give me a definitive answer, but it did send me in the right direction. I determined that the calibration factor for the paddlewheel had somehow been set to zero. I'm not sure how this happened and it is making my concerned for the rest of the system. I applied an immediate factor of 6.25 as suggested by the above document (6 blade paddle wheel) and the displayed boat speed numbers were in the right ball park. But a quick check against SOG indicated that they were still inaccurate. So now I have to do a full calibration run to set the correct factor.
I'm just perplexed that the stored value got lost. Hopefully it doesn't indicate a bigger problem.
For now, I'll stop hijacking the Expedition forum with B&G issues!
Fergal.
Every so often, or when I change things ,I upload all the boat's B&G Cal values to Expedition and then save thgem as a file, and rename it using the date as part of the file name. That way I always have a complete set of cal values I can load back into B&G when things go wrong in the strange black world that is B&G. Works for me, has saved our bacon a few times. I tend to use Expedition to manage the B&G cal values in any case as it's easier, so Exp always has a good set of values available in any case.