The brushless plastic housing is 30% thicker in the thinnest areas and I feel like the upper bearing support is better as well. It also has a more consistent air gap around motor and plastic case. Also noticed all hardware is bigger.
Hopefully the brushless will create much less heat because its more efficient. Really depends on what kind of amps it will be pulling. Not worried though, the big shapeoko spindle mount is a great heatsink!
On a side note both my corded bearings have measurable axial endplayā¦ definitely going to look into higher quality replacements and establish a service interval
Edit 90 watts is enough to run no load at speed 1.5
As far as the commutator wear, I wonder if the the āsock modā a la @RichCournoyer would help with that? Especially since youāre loading it up and cutting without dust collection, the router could be sucking small particles through it and basically sanding the brushes/commutator. I forget where it was posted, but I remember @RichCournoyer mentioning that he had many many hours of heavy use on a single set of brushes. Maybe if I mention his name a couple times heāll show up and comment;-)
Imo the off the shelf compact routers are a wear item and easily replaced when worn. The Makita can be had for little over $100 shipped with 4 year warantee. A couple years of hard use is pretty dang good. I also run a sock (take it off for photos).
@RichCournoyer already expressed that the brushless looked gutless.
Now Iām wondering if there is a way to trigger feedhold automatically if this thing dies quickly. If not Iāll test using heavy adaptive horizontal runs @28k and stand ready. I could see what kind of amps this thing pulls easily as well under load and no load conditions
Trial by fire as they say
I love the math, but Iām also optimistic. Time IS money, but everything has a scale. Ac/dc compatibility is a big benefit for my long term goals.
This forum is awesome! I think if it had existed in the far off past it may have been possible to bring Edison and Tesla(the man, not the car) here to discuss the merits of AC versus DC,ā¦without the need to electrocute an elephant! Great discussion brings great ideas, and great ideas arenāt always followed by āHold my beer and watch this!ā. Iāve got my tinfoil hat on and Iām watching eagerly!
if I was a betting man I would probably put my money on Richard.
How does Makita rate the rt701c @ 1.25 hp and claim 6.5amp draw? ohms law doesnt apply cleanly to ac power right? Most charts i see claim 6.5 amps for a 120v ac motor to be anywhere from 0.5-1hp, and thats no load.
I have zero education on electrical and maybe im missing something but what if the RT701c isnt really 1.25 hp
1 Like
CrookedWoodTex
(Tex Lawrence (Don't Mess With My Texas!))
32
How does Makita rate the rt701c @ 1.25 hp and claim 6.5amp draw?
HUGE SIMPLIFICATION
A BrushLess DC (BLDC) motor contains its own electronic switches instead of a commutator that is mechanically switching/reversing the polarity. These electronic switches are essentially ON or OFF with very little power consumed in the switch itself. In other words, at the moment one of these switches is ON, it has very little resistance to the current flow. (Note that brushes, which a BLDC does not have, are high resistance switches and are even momentarily power-consuming short circuits as the rotor rotates.)
So, during the momentary ON state you would calculate (via Ohmās Law) very little power āwastedā by the switch itself. Conversely, there would be more power available to produce more torque for rotor movement.
As an aside, the momentary ON state is also duration tuned to only provide enough current to efficiently operate the motor, thus saving current there, too.
Thatā's probably āPeak HPā which is more a marketing term and factual from my experience.
1 Like
CrookedWoodTex
(Tex Lawrence (Don't Mess With My Texas!))
34
āā¦ probably ā¦ā Is Makita normally overstating its ratings? It is really easy to write off everything to āmarketingā, but BLDC motors will surprise you; just look at the tiny fans that are around. They didnāt show up until BLDC motors became abundant.
I did the math too, and I agree that some numbers are wonky. Based on the real world test of the 5Ah battery lasting 30 minutes, it would seem that the continuous power is roughly in the 1/4hp range instead of the claimed 1 1/4hp.
Handling adaptive great at 22krpm, 75ipm, 0.04 opt and 0.08 Doc. This is super conservative for me but Iām running on the stock s3.
@Griff Motor is 80 degrees after almost 100% continous load cutting. Iāll get some decibel ratings tonight, just cause I love you guys. Power supply not even warm.
That was one a 3 flute 250 TAS with one tip missing, switching to good 250 single flute.