Exactly, I was rebuilding 6 speed sequential dog boxes when I was 15 years old. My motocross bikes had them. They were so simple, with none of the synchro nonsense with all the baulk rings and springs.
I think clutchless shifting on that thing would be rather tricky, compared to a normal bike shifter setup. Can I ask what kind of controller you are going to use?
Im not too sure yet, something by texas instruments perhaps, or something from RS. I can see myself just getting a pcb schematic and building it myself though. The driver circuit is pretty basic really, but with the above kits, there is no need to write code, as you would with a self build. They come with fancy Cds, where you clock in the inputs in English, in a nice table, you then save this to the board via the usb and away you go. The kit from Texas> I snipped out page instead of posting link, links can die after a while The nice thing as I said about that is that its user friendly. But, costs about 200dollars, and the stepper that comes with it would need to be replaced for another type. Building the board myself is far cheaper, but I then have to deal with coding the (say) L297 or whatever micro.c I go with in the end.
Thankyou, that sortv'e kit makes sense, but I'm guessing torques required for shifting are going to take a reasonable amount of power to be supplied to a stepper motor. Guessing a development type board from texas may not have the guts to run that sort've power. But I'm sure you'll cover this all later on, mechanical stages need sorting first.
Indeed, I read that the dev board can handle the nema 34 frame stepper with a few small component upgrades, but Im not that bothered as yet as you said. Plus, having a bro an electronic engineer for 25odd yrs eases me a bit too about the whole thing. But, Im only going to contact him at the last resort. Trying to decide what size stepper Ill need was a bit of a head scratcher for a while. Ive come up with the Idea of using a torque gauge on the end of drum near completion, shouldtell me a ballpark torque required Nm figure. Another thing I am thinking about is the syncro engage time delay/line up delay, its not the same time exactly at all speeds. This has me wondering if I should put a flexible coupling between stepper shaft and drum to act as a torsion damper/give syncro time to engage. This would allow me to use constant step times for all engine/road rpm. An internal spring loaded hub would do the same for me. Just something to keep the hub/fork under preload while the syncros are seating, and also allow stepper to reach its predetermined step angle position without binding/overload/strain. Thats also stuff I have to think more about. BG
Interesting, looks like the paddles control the shifter lever via pneumatics? Im sure you all saw this too>
May not even be pnuematics Brian. It reminds me of the unit used with this system. http://www.kliktronic.co.uk/
I could always use the old lego pneumatics for a mockup too At the minute, pneumatics are doing anything for me, since a ratchet system is needed then on the end of the drum. I could of course run a rack at 90 degrees to the drum, engaging on a pinion on drum, and control that rack with pneumatics. But, Im not sure how you control specific amounts of air in indexed steps. And, at different temperatures it would all change ever so slightly. Lots to think about thats for sure.
Indeed, Dogwood's! How does the remote shifter stuff (on this thread) interrelate with the limitations of OEM syncros / clutch? Or has the thread strayed a little?
Chris, discuss all if you wish, split it off to another thread then if it gathers pace, In the mean time Ill continue figuring out the job at hand.
Fine, just read back - looks like it has strayed. Will leave for now rather than break the flow. Split later.
