Hi all,
I'm new to these forums and hope this is the proper location for this post.
I'm looking into building an electric kart for my 9 year old daughter to use in our local SCCA solo Junior Kart program and hoping to tap into the knowledge base here.
My current plan is to use the following Motor: Mars ME0909 PM pancake motor. http://www.cloudelectric.com/productdetails_popup.asp?productcode=MO-PTX-0909
One of the requirements I have set for myself in this build is to have the capability to remotely(I'm into RC planes and cars, so I have the transmitters/receivers) shutdown the kart in the event of an emergency. Preferably being able to use regen braking to quickly slow it down and not just cut all power allowing it to coast. I called Alltrax and spoke to tech support and apparently they do have a controller that I could make work by remotely activating the key switch, and the controller would go into regen braking, but it only works on shunt motors like the D&D, but those may be far to heavy and a bit over my overall budget. I couldn't find a number for Kelly Controllers, but I think they may have something that would work with the Mars Motor above. Any ideas?
Ok so that is my basic question, if you would like some more background info feel free to continue reading below.
For those that are not familiar with autocross... well I think wikipedia describes it best.
Currently the SCCA Junior Kart classes only allow a limited set of gas 4 and 2 stroke motors, namely the Yamaha kt100 and the Briggs and Straton World Formula. To keep speeds down restrictors or smaller carbs are used, but the kids still can get speeds up to 40 mph in FJB (9-11 year olds) and upwards of 50 mph in FJA(12-14 year olds). I would like to keep the electric motor on par with these gas engines as the ultimate goal here is to get the SCCA to allow two new electric kart classes. So parts need to be off the shelf and readily available and at a reasonable price. A Briggs and Straton World Formula motor that is race ready runs about $1000, so I've set that as my budget for Motor, Controller, and other misc items minus the batteries. Of course if I can come in under $1000 even better as this would probably appeal to more parents in our sport. I think this format of competition is ideal for an electric kart because we only need enough battery power to make four runs. Each run rarely goes over 60 seconds in length so total run time per event is maybe 5 to 6 minutes.
Here are the weights I have to work with. A rolling kart chassis minus engine and fuel tank comes in at around 105 lbs. The rules for FJ classes stipulate a minumum weight of 250 lbs with driver. My daughter weighs 60 lbs. So that gives me 85 lbs to play with. The Mars ME0909 weights 24 lbs, a 300 amp Kelly controller 6-10 lbs? That gives me 50 lbs for batteries. I'm not sure I want my daughter surrounded by heavy AGM, or SLA batteries at 12 to 20 lbs each. Instead I'm thinking of the same Lipos I use for my RC airplanes. HobbyKing has some 6S1p 8000 Mah batteries that weight about 2.5 lbs each. Four of those setup as 12s2p at 16AH would weigh 10lbs. After 6 years of flying with lipos in my planes I think I could comfortably come up with a safe way to use them in my daughters kart.
So that is my novel, If you read all that I really appreciate it and would welcome any advice you may have.
Thanks,
Paul
So my main objective is to be able to accomplish this safely.
I'm new to these forums and hope this is the proper location for this post.
I'm looking into building an electric kart for my 9 year old daughter to use in our local SCCA solo Junior Kart program and hoping to tap into the knowledge base here.
My current plan is to use the following Motor: Mars ME0909 PM pancake motor. http://www.cloudelectric.com/productdetails_popup.asp?productcode=MO-PTX-0909
One of the requirements I have set for myself in this build is to have the capability to remotely(I'm into RC planes and cars, so I have the transmitters/receivers) shutdown the kart in the event of an emergency. Preferably being able to use regen braking to quickly slow it down and not just cut all power allowing it to coast. I called Alltrax and spoke to tech support and apparently they do have a controller that I could make work by remotely activating the key switch, and the controller would go into regen braking, but it only works on shunt motors like the D&D, but those may be far to heavy and a bit over my overall budget. I couldn't find a number for Kelly Controllers, but I think they may have something that would work with the Mars Motor above. Any ideas?
Ok so that is my basic question, if you would like some more background info feel free to continue reading below.
For those that are not familiar with autocross... well I think wikipedia describes it best.
An autocross is a timed competition where drivers navigate one at a time through a temporary course marked by traffic cones, rather than racing on a track with multiple other cars, as in road racing or oval racing. Autocross tends to place more emphasis on car handling and driver skill than on sheer horsepower, and events typically have many classes which allow almost any vehicle, from economy sedans to purpose-built vehicles, to compete. Speeds are slower in absolute terms when compared to other forms of motorsports, usually not exceeding highway speeds, but the activity level (measured in discrete turns per minute) can be higher than even Formula One due to the large number of elements packed into each course. Autocross courses are typically 40 to 70 seconds in length, with speeds limited to 70 mph for insurance purposes.
Currently the SCCA Junior Kart classes only allow a limited set of gas 4 and 2 stroke motors, namely the Yamaha kt100 and the Briggs and Straton World Formula. To keep speeds down restrictors or smaller carbs are used, but the kids still can get speeds up to 40 mph in FJB (9-11 year olds) and upwards of 50 mph in FJA(12-14 year olds). I would like to keep the electric motor on par with these gas engines as the ultimate goal here is to get the SCCA to allow two new electric kart classes. So parts need to be off the shelf and readily available and at a reasonable price. A Briggs and Straton World Formula motor that is race ready runs about $1000, so I've set that as my budget for Motor, Controller, and other misc items minus the batteries. Of course if I can come in under $1000 even better as this would probably appeal to more parents in our sport. I think this format of competition is ideal for an electric kart because we only need enough battery power to make four runs. Each run rarely goes over 60 seconds in length so total run time per event is maybe 5 to 6 minutes.
Here are the weights I have to work with. A rolling kart chassis minus engine and fuel tank comes in at around 105 lbs. The rules for FJ classes stipulate a minumum weight of 250 lbs with driver. My daughter weighs 60 lbs. So that gives me 85 lbs to play with. The Mars ME0909 weights 24 lbs, a 300 amp Kelly controller 6-10 lbs? That gives me 50 lbs for batteries. I'm not sure I want my daughter surrounded by heavy AGM, or SLA batteries at 12 to 20 lbs each. Instead I'm thinking of the same Lipos I use for my RC airplanes. HobbyKing has some 6S1p 8000 Mah batteries that weight about 2.5 lbs each. Four of those setup as 12s2p at 16AH would weigh 10lbs. After 6 years of flying with lipos in my planes I think I could comfortably come up with a safe way to use them in my daughters kart.
So that is my novel, If you read all that I really appreciate it and would welcome any advice you may have.
Thanks,
Paul
So my main objective is to be able to accomplish this safely.