Gear & Transmission - Installing a gear indicator
Last Updated on Monday, 29 March 2010 10:47 Written by Nicolai Due Wednesday, 10 March 2010 15:36
When you are driving a racecar it is important to know which gear the vehicle is in at all times. To do this you need a gear indicator, and they come in many different types. On the previous Vikings this gear indicator was quite troublesome, so this year we wanted a solution without glitches. So to make a glitch-free solution the Transmission Team got to work with the Engine Team.
More detailed information about the issue with the gear indicator is awaiting for those who click on the "read more"-button.
On the Viking II car, there were a lot of problems with the gear indicator. This was because the position of the gear was calculated, when the gear actuator was activated. This was a problem when the car was turned on, whilst not being in neutral gear, because the indicator would then be wrong. To overcome this issue on the Viking III, it was initially the idea to insert a rotary potentiometer and connect it to the shift drum (See picture). This was then investigated: First the service manuals were looked through. This however did not provide the team with much information, since there was only a picture of the shift drum, but it was not possible to draw any conclusions from the picture. The team now knew that there was only one thing to do: Disassemble the crankcase and measure inside it. The Transmission Team then contacted the Engine Team and scheduled a date for disassembling the crankcase.
Sunday the 28th of February the crankcase was disassembled. This was done by two from the Engine Team, Carsten Pedersen and Dennis Hamborg, and me (from the Transmission Team), Nicolai Due.
The first step was to remove the clutch. The plates were easily removed, by unscrewing the bolts, but the clutch outer was not as easy. This must be removed with a special tool to hold the clutch outer in place, while the lock nut is unscrewed. There was a problem though: This tool was not at our disposal, so we would have to make our own. It was made from a circular plate with a hole in it, and holes were drilled to attach it to the clutch outer with bolts. Also a 400mm rod was attached. The tool was now used to remove the clutch outer. Then all of the bolts on the top of the engine were removed, and the engine was flipped to access the bolts in the bottom. These were removed in the order specified in the service manual, and the crankcase was removed. It was now possible to draw a conclusion: It is not possible to place and connect a rotary potentiometer to the shift drum. But the teams were not yet ready to give up. The standard Honda CBR 600 RR has an indicator for neutral gear. The plan is now to replace the standard switch indicator, with a linear potentiometer, and make a special part for the shift drum. To do so the shift drum must be modified slightly. This modification must be very precise to avoid any accidents while the car is running. To ensure maximum precision the shift drum will be scanned with the 3D Laser Scanner available here on the Faculty. This way the shift drum can be edited in CAD-programs and the optimal solution can be simulated and the best part to fit the linear potentiometer can be machined.
In the upper right corner is a screenshot of the shift drum from the CAD-program after the 3D-scan. The red line indicates the path of the standard neutral gear indicator. Below is a picture of the manufactured clutch removal tool.
