Navman S100 Satnav Mount Plate.



The Idea:

To modify the homemade Universal Handlebar Platform Mount that I made at an earlier stage of a different project to house other homemade components so as to be able to mount my Navman "Spirit" S100 Satellite Navigation System at a reasonable viewing angle, something around 20° extra to the handlebar mount which already sits at about 20° giving a total angle of 40°.

The Wedge Components:

The first task was to manufacture the 20° angled wedge components out of Aluminium plate that happened to be 9mm thick. The width of the component was made to be 48mm, (slightly less than the platform mount width) and the highest point measured 34mm at the start of the 20° angle. Working from the centre of each face in turn I put two M5 x 0.8mm tapped holes on each angled face, 34mm apart to a depth of 8mm of thread then turning over to the other face I drilled two 3.3mm diameter dowel holes 34mm apart for a depth of 8mm. In the centre I drilled and tapped an M5 x 0.8mm hole to a thread depth of 16mm. These holes are then used to fix the wedge components to the platform mount, (see Figures 1 to 4).

The Platform Mount Modification:

To fit the wedge components to the platform mount new holes had to be drilled and counterbored into it to accommodate the fittings, as usual I worked from the centre of the plate. The first job though was to try and loose some weight from it as the thing was getting a bit heavy!
  • To reduce weight I machined the thickness of the platform mount down to 16mm from 19mm.
  • Drill four diameter 3.3mm holes through the plate 17mm up and down and 59mm left and right across from the plate centre.
  • Drill two diameter 5.2mm holes 59mm left and right on the plate centre line.
  • counter bore these holes to a diameter of 9mm to a depth of 8mm on the underside, (this is to accommodate the two M5 x 0.8 x 20mm cap head bolts, see Figure 3 which is an underside view showing the new holes).

The Adapter plate:

As this is unique to the satnav device I have chosen to use, (a Navman "Spirit" S100 Satellite Navigation System) I am not going to go into too much detail with dimensions at this stage as they would only be relevant to the S100 and therefore pointless if a different satnav system is to be used. The idea however should be similar.
  • Machine a piece of Aluminium 150mm x 88mm x 18mm, (the S100 satnav unit measures 130mm x 78mm x 13mm).
  • Machine a pocket in the plate to leave a 10mm thick edge left, right and bottom to the measured satnav sizes, (see Figure 5 and 6).
  • Drill and tap three M4 x 0.7mm tapped holes 10mm deep evenly spaced either side along the centre line of the wall thickness, (again see Figure 5) take a note of the dimensional positions as they will be needed later for the cover plate, (Figure 7).
  • Drill and countersink four holes to accommodate the four M5 x 0.8 x 8mm countersink screws. These holes should match up with the ones on the angled wedge components.
  • Machine any other holes or pockets that may be required for access to any jack plugs, speaker holes or buttons on the chosen satnav unit.

The Cover Plate:

This is literally to stop the satnav unit falling out of the adapter plate. It is a piece of 2mm thick Aluminium that is to the same external dimensions as the adapter plate, (150mm x 78mm) but the internal size is smaller in width than the adapter plate internal pocket by 12mm giving an overlap each side of 6mm. It is held in place by six M4 x 0.7 x 8mm cheese head screws that each have a spring washer underneath to allow movement in the cover plate, (see Figures 7 to 9).

The Assembly:

First fit the two 20° wedges to the platform mount. This is done by locating the wedges using the four split dowels, (two for each wedge) and bolting the wedge down from underneath using the two M5 cap head bolts. Using the four M5 countersink screws the adapter plate is fitted to the angled face of the wedges. The cover plate is then fitted using the six M4 cheese head screws with spring washers underneath, (tighten these screws until a slight resistance is felt, do not over tighten) this allows the cover plate to move within the tension of the spring washers. It may be a good idea to use a retaining compound on the threads of the screws to stop them undoing due to vibration. See Figures 10 to 12 for the fitting components and finished article.

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View of all the components required to fit the wedge section to the modified platform mount.
20° Angle Wedge Components.
Figure 1.

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Figure 2:
Isometric views of the two 20 degree angled adapter wedges.
20° Angled Adapter Wedges.
Figure 2.

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Underside view of the shot blasted modified platform mount. The modifications being...
1: The drilling of four 3.3mm diameter holes suitable for split dowel pins. 2: Drilling and counter boring two holes to suit an M5 x 0.8 x 20mm cap head bolt. 3: To reduce weight a further 3mm was removed from the top mounting face.
Modified Platform Mount.
Figure 3.

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Figure 4:
Isometric view showing the wedges bolted and dowel pinned in place on the platform.
Modified Mount & Wedges..
Figure 4.

Click For Larger Image. Adapter Plate.
Figure 5.

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Figure 6:
This image shows how the Navman S100 unit fits snugly inside the adapter plate.
It is not a force fit so as not to damage the unit but there is slight resistance when the unit is slid into place.
Adapter Plate & S100 Unit
Figure 6.

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Figure 7:
The cover plate is made from 2mm thick Aluminium and is held in place with six M4 x 0.7 x 8mm bolts.
The lip overlaps to retain the Navman S100 unit but still leaves the whole screen visible.
Cover Plate
Figure 7.

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Figure 8:
Cover plate and six retainer screws. Spring washers are used to allow cover plate movement to retain satnav unit.
Note the four countersunk screws that bolt the adapter plate to the angled wedges on the platform mount.
Cover Plate & Adapter Plate.
Figure 8.

Click For Larger Image. Cover Plate & Navman S100 Unit.
Figure 9.
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Figure 10:
Two M5 x 0.8 x 20mm cap head bolts, four M5 x 0.8 x 8mm countersink screws, four diameter 3.3mm split dowel pins, six M4 x 0.7 x 8mm cheese head bolts and six 4mm diameter spring washers used to assemble the components.
Component Fixings.
Figure 10.
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Figure 11:
Underside view of all the components bolted and pinned together.
Underside Assembly View.
Figure 11.
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Figure 12:
Painted and assembled face on view of all the components bolted and pinned together.
Face On Assembly View.
Figure 12.

So Did It Work? (13/05/11):

Well yes and no. The bracket holds the satnav unit in place like it is supposed to and the positioning is pretty good for angle and viewpoint. Unfortunately the screen is hard to see with a crash helmet visor and sunglasses, (which is what I wore today whilst testing it) so I had to rely on audio directions which was very clear. This was achieved using "in ear" headphones, (which were quite comfortable surprisingly) and I did reach my programmed destination without a hitch. I have since found some more settings and increased the brightness of the screen from 70% to 100% so I will see how it fares next time. The other downside is that I got a low battery warning after about 45 minutes of use. The power in slot is the same as the audio out slot, (uses an adapter block for a 3.5mm audio jack plug) so I can't use power from the bike. It would be OK to get you out of trouble if you got lost but a journey of more than 45 minutes and it would struggle.

Click For Larger Image.
Figure 13:
The adapter brick plugs into a port in the bottom of the satnav unit which allows a standard 3.5mm stereo audio jack to be used for headphones. Unfortunately this means the unit cannot receive power as it uses the same port for this. This also means that there are trailing wires which was OK as long as you remember to unplug the headphones when you get off the bike. (To stop the adapter brick being lost should it fall out due to vibration I have attached it to a lanyard which is tied to the handlebar clamp bracket).
Audio Adapter Brick.
Figure 13.

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Figure 14:
Placement of the satnav unit from the riders point of view, (no power to screen in this image). Notice that the position of the bracket does not interfere with the view of the instrument cluster which was one of the reasons for mounting it in this position in the first place.
Placement On The Bike.
Figure 14.