by HomeRacingWorld » Wed Feb 13, 2019 9:52 am
For anyone wanting to begin testing yourself, here is my advice from the skills taught to me over the years:
1. A low cost "Ebay" laser tachometer is just as accurate as a high dollar one. I have access to 2 different tachs that cost ridiculous money. The results? The same. Most are within 15 to 25 rpm. That is basically nothing when you are measuring these motors. I have tested 5 or 6 brands over the years against my calibration machine. Trust me, a $15 tach does the job.
*** I will add that one needs to read the initial post above. This new SOUND APP is just as good. I am just impressed by it's accuracy***
2. Motors go through a break-in period before delivered to dealers. The only thing you will gain by more break in run time is usually slight increases in RPM as the small brushes improve their seating against the commutator. I bench test the motors for 2 minutes at 12 volts. This is the voltage 98% of end user/enthusiasts will do, so that is how I test them.
3. An easy way to make a disc for the motor is to use plastic pinions. They are easy to press on and off, but hold tight during testing. Glue the pinion over some styrene plastic and paint it flat black. Reflective tape is easily found in the cycling area of Walmart or even in the scrapbooking section. Reflective chrome auto pinstripe is not as reliable as you would think.
4. Sometimes a "slow" motor does not have the brushes seated properly. The tabs that hold the brushes through the endbell are sometimes not mounted evenly. You can take them out on some motors, or using a needle nose pliers you can adjust them. The one shown in my test has a removable mount, so it was easily pushed out.
5. Other times the bushings on either end might not be seated well. This causes binding. Normally I have not had luck trying to seat them correctly.
6. You will soon discover that there is literally no difference between a "name brand" high dollar motor and a lower cost alternative such as the series of motors from SCC/Cloverleaf, MT Racing, etc. They are all made in the same place most instances and the only difference is the wrapper/markings on the outside.
7. Some companies DO field test motors and try to match the motors they install in their models. Yet, the variance is still 800 to 1000 RPM in my testing results.
8. Acquire a low cost, adjustable bench supply. I cannot stress how convenient it is to have a dedicated supply. I run my Tire Razor, SCC Roller Test Bench, and my motor testing all from one supply.
9. You WILL see different readings from other people testing. These motors are made in batches. The variances can sometimes be quite a lot. I have tested motors from Fly for example that had a 3000 RPM variance. This was in the same model, just different paint schemes and release dates.
10. All the data in the world doesn't amount to a hill of beans. It is ON TRACK TESTING that is the best way to find out if you like a motor.
All of us have different tastes in speed, braking, etc. All of us have different tracks. I might like a motor...you might hate it. My testing just combines some of the data, with a good road test.
I like this motor, but not as much as I like the standard Piranha. The original has proven itself in our Showdown Series over the years to be a very quick, responsive, and durable motor. We have enough speed for my smaller oval...so I won't be changing the rules.
But I am betting this new ball bearing version will reveal itself to be just as good for some of you out there looking for a new "Spec" motor.