My triumphant arrival at the finish line! We even managed to have some fun along the way.Įnjoying a few miles of off-highway riding on a very nice bike trail.Īt a food stop on Day 2, in front of the “World’s Largest Egg” in Winlock, WA. While we were among the slower riders in the throng of 10,000 cyclists, we got it done. We’d never done a century ride before, much less two of them back to back. When I last wrote, CFL and I were training for Seattle to Portland (STP), a two-day, 206-mile bike ride. The year 2016 has been a stampede of events upon events. Looking ahead, I expect 2017 to be even busier! There are always upcoming events to train for, the actual events to experience, and then the very brief period of rest and recovery before ramping up for the next one. Time has a way of going quickly when you are busy doing things that you love.Īs I approach the end of my fifth year of post-corporate life, I continue to be amazed at the lack of white space on my calendar. Sometimes a thrust washer will allow a motor to turn freely when not energized, but when power is applied and the armature shifts to its "magnetic" center, it binds.īigbillnky,C.E.F.(Chief Electrical Flunky) RE: DC motor running slow.It’s been a long time since I’ve posted here. Other than that, I would check the bearings. Use ohms law to calculate correct winding resistance based on the nameplate field voltage and current. If you are interested, you can Google "field weakening DC motors" and you will be able to find relevant information that explains how the field current and armature current interact.Īlso, check the field winding resistance.
Typically, diode failure in a controller that has a seperate power supply serving the field winding causes a higher than normal field current, which in turn limits the armature speed.
I would test the field current with the motor running and make sure that it matches the motor nameplate.
#NO LIMITS 2 COASTER RUNS TOO SLOW HOW TO#
How to ID concerns jimm圓456 (Aerospace) 17 Dec 10 12:17ĭo these motors have a wound field? If so, the field current could be the cause of the speed variation issue. It really reads like there's some kind of mechanical problem though. the whole thing is likely a candidate for replacement. It should have a consistent chocolate brown appearance all the way around.Īny indication of a bar being discolored is a sign the armature is "shot", and reluctantly. Utilize a flashlight and look into the motor through the brush opening and inspect theĬommutator as the motor shaft is rotated (if you even can). Mechanical drag as mentioned already is likely hampering movement.Īs far as brush appearance? In addition to looking at remaining brush length look for any sign of heat damage to the brush springs,Īnd whether the shunt wires have not been broken. In performance like in the case of an internal combustion engine. Small permanent magnet motors (or actually most all kinds of electric motors) typically don't have any progression downward If indeed two motors have lost their "snappy like" behavior, waross is correct in checking supply voltage. The title of the post, "DC motor running slow." implies only one motor, and the body of the post indicates a problem with two motors.