|
1
« Last post by webby2 on Today at 09:13:26 pm »
A small side track.
Concept test bed, not an optimized machine. Same hardware, same 12 V Yellow TT drive, same NEMA23, and two 50 Ω coil loads. Only the return/sun gear ratio was changed between runs. The table shows measured current/RPM data plus calculated carrier/slip values. Estimated coil voltage/power values are based on separate NEMA bench calibration and are not direct in-system measurements.
90/30 open RPM values in the table are the corrected rerun, 263/792, not the original bad tach reading.
2
« Last post by webby2 on August 24, 2026, 01:29:59 am »
something that has been bother me with this is that the math only shows 1/2 of the input coming back to assist and I did not see why that would be, well I finally figured that out and it is so silly that it is embarrassing that I missed it.
There are 3 systems lets say,, there is the upper input section, the slip and then the lower return section. The upper and lower share a physical connection on one side and a force connection on the other and it is that force only connection where the slip is.
Now if the input goes in on the upper and it spins the upper and then the upper goes across the slip and spins the lower and then the lower comes back to assist the upper,, the simple thing is that the slip boundary has the upper traveling at say 100 RPM and with the 2:1 return gearing the lower is traveling at 50 RPM, so the same force but at half the rate means half the return work,,, and that is why there is only 1/2 of the input returned to assist.
3
« Last post by webby2 on August 13, 2026, 04:18:28 am »
The printer I used for the frame sections had an issue that I have now resolved. I reprinted those parts and also made the dual ring gear, or hybrid ring gear, a little stronger so it is less prone to deforming under load. I also found two bad pivot bearings and replaced them.
As tested:
28 bearings
17 gears
Blue motor alone: 0.07 A
1:1 direct head-to-head, 1 Blue driving 3 Yellow:
0.48–0.50 A
2:1 system, no load motors:
0.16–0.23 A
1:1 system, no load motors:
0.18–0.24 A
2:1 head-to-head through the system, 1 Blue driving 3 Yellow:
0.45–0.54 A
All tests were run at the same 6 V power-supply setting and allowed to run until reasonably stable.
These are the measured numbers from this build. They are not being presented as evidence of gain; they are simply the results from the current configuration.
4
« Last post by webby2 on August 03, 2026, 05:13:04 pm »
there seems to be an error on the calculated TT motor turn ratio,, so those conclusions are wrong. Sorry for the confusion.
5
« Last post by webby2 on August 02, 2026, 09:16:43 pm »
the yellow motor was not going to cut it so I changed it up for a blue body all metal TT motor,, well then I got a little carried away with doing some silly testing and this pdf sums it all up fairly well.
a reduced cost is pretty cool when it matches the math to the bench.
6
« Last post by webby2 on August 02, 2026, 06:14:23 am »
here are some premature test runs for setting a base line,, with this run however the Blue TT motors are geared down 4:3 to the input drive gear.
Configuration / Setup,Input Voltage,Total Input Current (Iin),Net Current over Motor Tare,Generated Output / Status,Bench Notes
Yellow Motor Alone (Tare),6 V,0.11 A,0.00 A,N/A,Baseline internal motor + gearbox friction.
Yellow + Bare Frame Stack,6 V,0.22 A,0.11 A,N/A,Frame bearings (8 mm shafts) & structure add just 0.11 A drag (no 80T gear).
1 Blue TT Motor (Direct Drive),6 V,0.35 A,0.24 A,5.0 V Open Circuit,Smooth single-branch baseline; yellow motor stays cool.
2 Blue TT Motors (Direct Drive),6 V,0.54 A,0.43 A,—,Linear load scaling up to 2 direct-driven gearheads.
3 Blue TT Motors (Direct Drive),6 V,0.70 A→0.95 A,>0.59 A,Stall / Thermal Limit,"Torque limit exceeded; armature back-EMF collapses, cooking motor windings."
3 Blue TT Motors (In Planetary Loop),6 V,0.31 A−0.34 A,0.20 A−0.23 A,Feedback Loop Active,Key Result: Loop force cancellation drives all 3 motors for less current than 2 direct-driven motors!
1 Blue TT Motor (Under Peak Short-Circuit Load),6 V,0.78 A,0.67 A,0.110 A−0.120 A Peak,Measured across DMM 200 mA range (∼0.5Ω shunt load). Heavy magnetic back-torque.
7
« Last post by webby2 on August 01, 2026, 10:31:07 pm »
an inside look with the 80T upper gear and the TT motors removed to expose the lower 30T internal ring gear with its 20T mate
8
« Last post by webby2 on July 30, 2026, 08:54:33 pm »
I still need to print out some more spacers, cut 2 shafts shorter, build the electronics package, build the motor holder and the motor coupler.
It is coming along and so far it all spins fairly well.
9
« Last post by webby2 on July 30, 2026, 07:32:45 am »
printing off parts that should be the final parts,, should be because so far I have messed up a few print changes,,,,,
An interesting observation is that the "pin" when only between 2 pivot bearings can twist out of alignment, meaning that the pin is not 90 degrees vertical to the pivot bearing face,, good thin I built in a gear sync system for that part.
With all of the test fits so far the system actually can spin very smoothly which, with all of these gears,, is a little surprising but very good.
10
« Last post by webby2 on July 26, 2026, 11:36:38 pm »
the build so far
|
Recent Posts