BRIAN RANDALL
New Member
New owner of a 1985 Sundancer. Just hauled the boat out for maintanence and noticed the transom mounted speed wheel was broken. Is it recommended to replace it? Boat doesn't have autopilot, does have Raymarine radar setup.
Speed Wheel Replacement
- Thread starter BRIAN RANDALL
- Start date
Getaway
Well-Known Member
- Oct 13, 2010
- 1,077
- Boat Info
- 1998 290DA Sundancer
Lowrance electronics, Fishhawk, Scotty Downriggers
BoatWheels Tri-Axle Trailer
- Engines
- Single big block 454 MPI Mercruiser engine and Bravo III outdrive.
That must be for your sonar or something. The Sea Rays had plastic tube pickup that hung down by the lower unit for your speedometer. I got rid of mine a long time ago and use the speed readout on my GPS.
CapTwiggy
New Member
- Sep 11, 2022
- 26
- Boat Info
- 1985 Sea Ray Sundancer 270
- Engines
- I/O Twin 185hp Mercruiser
Do you have a manual for this boat? I'm looking for a copy. Have you made any changes/updates to the boat? I'd love to hear from you.
DaveKamp
Active Member
- Jun 9, 2021
- 187
- Boat Info
- 1970 SRV180, '77SRV220CC, 76 SRV-240FB, another SRV180
- Engines
- Mostly MerCruisers with R-MR-Alpha drives
Wheel-type knot/log meters were common from the late '70's through the mid 90's, particularly on sailboats, slower planing and faster displacement hulls, because they were significantly more accurate than a pitot tube at slower speeds, but also because they provided speed/distance-through-water indication that would otherwise be no better than a guess with the pitot tube and dead-reckoning.
Nowdays, the GPS is accepted as more 'accurate' with respect to position-over-ground, but it doesn't indicate your speed through water, which if you're trying to determine currents, you're out-of-luck.
If the function of your knot-log system is important, replacing the wheel isn't difficult- typically it's just a wheel on a free-spinning axle, and there's a small magnet in the wheel, and a sensor in the bracket that detects the magnet as it passes by. If you have remnants of the wheel, take it to a kid who has a 3D printer, have him model a replacement of same diameter, melt one up, and transfer the magnet and axle to it, balance it on your kitchen counter with a pocket knife, and put it on- it'll work fine.
Nowdays, the GPS is accepted as more 'accurate' with respect to position-over-ground, but it doesn't indicate your speed through water, which if you're trying to determine currents, you're out-of-luck.
If the function of your knot-log system is important, replacing the wheel isn't difficult- typically it's just a wheel on a free-spinning axle, and there's a small magnet in the wheel, and a sensor in the bracket that detects the magnet as it passes by. If you have remnants of the wheel, take it to a kid who has a 3D printer, have him model a replacement of same diameter, melt one up, and transfer the magnet and axle to it, balance it on your kitchen counter with a pocket knife, and put it on- it'll work fine.
