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Don't underestimate them old tape drive motors! If it's as big as a
mower deck motor (3-4" in diameter, 6" or so tall), it's probably got enough
oomph for a kiddy car. In any case, from my experience, it would be better
to start out underpowered...... >>> "John de Rivaz" <John deRivaz com> 6/25/2002 3:07:56 PM >>> > I was checking in my shop and I have a 50 VDC nominal > motor (that came out of a 9-track computer tape drive made by DEC) I would rather doubt it. The power required to haul a kid about in a toy car is somewhat more than move tape. However there is a rule of thumb mentioned on this list or possibly a UK one which said that your electric motor can be 1/4 the horsepower of a gas engine used in a similar application. This is because the electric motor is capable of brief overloads, whereas a gas motor just stops. Therefore the gas HP has to be the peak load expected. If you know the sort of HP a gas engine would be, then divide by 4 and you get the electric HP needed. I HP = 746 watts. For a DC motor, the power in watts = emf (volts) x current (amps) x efficiency. Efficiency is high, about 90% (which would be 0.9 in the suggested calculation). -- Sincerely, John de Rivaz: http://www.deRivaz.com : http://www.AlecHarleyReeves.com http://www.longevity-report.com : http://www.autopsychoice.com : http://www.cryonics-europe.org http://www.porthtowan.com ----- Original Message ----- From: "SolidTech" <SolidTech qwest net> To: "'Elec-Trak'" <elec-trak cosmos phy tufts edu> Sent: 25 June 2002 18:18 Subject: (ET) Kid car idea > All, > Hoping for some thoughts on feasibility (and refinement) of the idea of > making a "better than retail" kid car. I know there's the plastic electric > vehicles you can buy at your local toy/department store. They always seem a > bit pricy for the mostly plastic thing they are. So... I was contemplating > a simple go-cart style vehicle with 1/2/3 batteries, a controller, and an > appropriate motor. I was checking in my shop and I have a 50 VDC nominal > motor (that came out of a 9-track computer tape drive made by DEC) and I see > there's various controllers on eBay. Questions: Is that electric motor > (Ametek brand) even appropriate for the task? What would be a reasonable > number/size of batteries? What would be appropriate for a controller? > > thoughts? > - - joe > > Joseph Rock > E-15 & MagnaTrac Hydro 5000 in Colorado > > |