ShiftPoint
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Nomadio Tach Install on a savage
this is the sensor and 2 magnets.
Here’s how I installed the tach sensor on my Savage X.
A place was needed to mount the sensor and 2 magnets that rotates and has to be after the transmission, the smaller diameter the better. I picked the cup the dogbones go into, first I marked 2 spots 180 degrees apart for balance.
(the silver dot)
Then drilled a hole to countersink the magnet.. After drilling the holes I cleaned up the plastic shavings from the hole with an exacto knife and cleaned the area with nitro cleaner. I inserted the magnets in opposite poles facing out you can do this by sticking the magnets together then marking the ends with a sharpie, then install them with the marked ends out this way the sensor can see the reversing poles.
. Next I epoxyed the magnets in place and covered over the top of them, I used 2-ton epoxy for this, I would have used JB weld but was afraid the metal content in the JB weld might interfere with the magnetic field’s./.
After the epoxy dried for the magnets I just used the 2 ton epoxy to tack the sensor board in place as close to the magnets as I could without touching them, after the tacking epoxy dried enough to hold the sensor pretty tight,. I then tested the placement by turning on the sensor and selecting the tach display, I spun the wheels and made sure I got a reading.
When I was happy with the sensor placement I cut 2 pieces of close hanger and laid them in place extending out over the side of the transmission casing and bent them so they were touching the sensor board, this was added just for some extra support. Then I used JB weld and covered the close hanger pieces and used it to hold the sensor tight. (we will see how long it holds)
I let it dry over night, and tested it using the tach display on the radio again the next day.
Now to get the settings for the radio so I will get correct speed readout..
There are 2 parameters needed to be set in the radio, rollout in inches, and rollout in revs, there are 2 methods of getting the number’s you need one is by calculating them, the other by actually measuring them. The measurement method was my first choice but that meant counting the number of turns for a distance the truck is rolled. This would have meant getting down on the floor and counting the turns, because of physical limitations due to illness I cannot do this. Plus the longer distance the more accurate the reading. Because of this I choose the calculation method which should be more accurate anyway.
First you need the dia of the tire’s, I have dogbones on this truck, I looked them up and found they are 150mm dia, I used google to convert this to inches and got 5.90551181 inch’s in dia. Then you take the dia and multiply it by Pi (3.14159265) so
5.90551181 x 3.14159265 = 18.55271 inch’s, so that is the circumference of the tire, or the distance the truck will roll in one revolution of the tire.
Since the tach sensor is in front of the differential we need the reduction ratio of the differential, the ratio for a stock diff is 43:13, so to figure out how far the truck will travel in one revolution of the axel. To do this take the ratio and divide the smaller gear (the one on the drive shaft to the transmission) and divide it by the gear on the dogbones turning the tires so in this case 13 / 43 = 0.302325 this number gets multiplied by the circumference of the tire so 0.302325 x 18.55271 = 5.6089 inches, that is the distance the truck travels in one rotation of the axel between the transmission and the diff. now this just needs to be converted into a fraction so it can be input into the radio. Do this by multiplying it by a number (200 or larger) I will use 500, so 500 x 5.6089 = 2804.45 rounded off to 2804 so the fraction would be 2804/500 these are the numbers to ebnte into the radio
Rollout in inches = 2804
Rollout in revs = 500
So for every 500 revolutions of the axel the truck will travel 2804 inches…
The same 2 parameters are needed for the tach setup, I just turned the cb till the axel where the sensor is rotated 1 time, it was about 6 turns of the CB for the axel to turn 1, this was a little off and will only be good for 1st gear since the radio has no settings for the other gears, plus it has no way to tell which gear your in anyway. I just used 6, and 1 in the tach setup.
I hope this helps, I couldn't find much of any info for doing this on a Savage. I would of had more pictures but my camera battery died on me during this so I missed out getting pic's on a couple steps.
this is the sensor and 2 magnets.
Here’s how I installed the tach sensor on my Savage X.
A place was needed to mount the sensor and 2 magnets that rotates and has to be after the transmission, the smaller diameter the better. I picked the cup the dogbones go into, first I marked 2 spots 180 degrees apart for balance.
(the silver dot)
Then drilled a hole to countersink the magnet.. After drilling the holes I cleaned up the plastic shavings from the hole with an exacto knife and cleaned the area with nitro cleaner. I inserted the magnets in opposite poles facing out you can do this by sticking the magnets together then marking the ends with a sharpie, then install them with the marked ends out this way the sensor can see the reversing poles.
. Next I epoxyed the magnets in place and covered over the top of them, I used 2-ton epoxy for this, I would have used JB weld but was afraid the metal content in the JB weld might interfere with the magnetic field’s./.
After the epoxy dried for the magnets I just used the 2 ton epoxy to tack the sensor board in place as close to the magnets as I could without touching them, after the tacking epoxy dried enough to hold the sensor pretty tight,. I then tested the placement by turning on the sensor and selecting the tach display, I spun the wheels and made sure I got a reading.
When I was happy with the sensor placement I cut 2 pieces of close hanger and laid them in place extending out over the side of the transmission casing and bent them so they were touching the sensor board, this was added just for some extra support. Then I used JB weld and covered the close hanger pieces and used it to hold the sensor tight. (we will see how long it holds)
I let it dry over night, and tested it using the tach display on the radio again the next day.
Now to get the settings for the radio so I will get correct speed readout..
There are 2 parameters needed to be set in the radio, rollout in inches, and rollout in revs, there are 2 methods of getting the number’s you need one is by calculating them, the other by actually measuring them. The measurement method was my first choice but that meant counting the number of turns for a distance the truck is rolled. This would have meant getting down on the floor and counting the turns, because of physical limitations due to illness I cannot do this. Plus the longer distance the more accurate the reading. Because of this I choose the calculation method which should be more accurate anyway.
First you need the dia of the tire’s, I have dogbones on this truck, I looked them up and found they are 150mm dia, I used google to convert this to inches and got 5.90551181 inch’s in dia. Then you take the dia and multiply it by Pi (3.14159265) so
5.90551181 x 3.14159265 = 18.55271 inch’s, so that is the circumference of the tire, or the distance the truck will roll in one revolution of the tire.
Since the tach sensor is in front of the differential we need the reduction ratio of the differential, the ratio for a stock diff is 43:13, so to figure out how far the truck will travel in one revolution of the axel. To do this take the ratio and divide the smaller gear (the one on the drive shaft to the transmission) and divide it by the gear on the dogbones turning the tires so in this case 13 / 43 = 0.302325 this number gets multiplied by the circumference of the tire so 0.302325 x 18.55271 = 5.6089 inches, that is the distance the truck travels in one rotation of the axel between the transmission and the diff. now this just needs to be converted into a fraction so it can be input into the radio. Do this by multiplying it by a number (200 or larger) I will use 500, so 500 x 5.6089 = 2804.45 rounded off to 2804 so the fraction would be 2804/500 these are the numbers to ebnte into the radio
Rollout in inches = 2804
Rollout in revs = 500
So for every 500 revolutions of the axel the truck will travel 2804 inches…
The same 2 parameters are needed for the tach setup, I just turned the cb till the axel where the sensor is rotated 1 time, it was about 6 turns of the CB for the axel to turn 1, this was a little off and will only be good for 1st gear since the radio has no settings for the other gears, plus it has no way to tell which gear your in anyway. I just used 6, and 1 in the tach setup.
I hope this helps, I couldn't find much of any info for doing this on a Savage. I would of had more pictures but my camera battery died on me during this so I missed out getting pic's on a couple steps.
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