Little review: DKLM RC 550-motored 4:1 gearboxes
Posted: Fri Jul 06, 2018 2:07 pm
Well. Finally bit the bullet and ordered the DKLM gearboxes with big 550 motors.
They're HUGE! However, I discovered -despite their size- they fit quite nicely in the Plastic Leo 2A6 chassis. it was a bit of an expensive gamble, and I was prepared to having to order the metal tub. But luckily, they -indeed- fit just fine.
There was, however, 'one snag : The casing is a bit concave on the bottom, so, when finally screwed in the tub, the shafts exited at an angle, and the motors looked crooked. In the end I epoxied' a 0.5 mm ring on top of the innermost standoffs in the tub, and hey, presto! Everything lined-up great. Had to cut 4 mm from the back of the battery-compartment, though, because the big motors and their mantle needed that space.
I also epoxied metal bushings around the standoffs, to prevent them from cracking when the screws go in. Added to that I epoxied an ABS-cross-beam on the bottom of the tub to give it a bit more strength. All in all, the gearboxes will fit the plastic tub, but not without a little plastic-surgery..
Everything works fine, the IBU2 isn't bothered in the least by the big 550-motors, that look decidedly like Graupner ECO 600-motors. So their max Amperage will be about 7Amp each.
Thing is.. it's not very fast now. Coming from taigen 1:3 with 25000rpm 490-motors, It even looks anemic. But that suddenly seizes to be a problem when the terrain becomes really rough, and by "really rough" I mean "Rutted and gutted agricultural lands".. The speed remains the same, whatever underground.. nice, impressive even. And the big, blue cooling fins..nice as they look, aren't really necessary. The motors get hand warm in an open tub, and no more than that, so they aren't really stressed..
I'm still a teensy bit bummed by the low speed, so the next things I'm going to test are the well-known Tamiya RS540SH/Johnson540's. I got a drawer full of those beercans.. all brand new.
An RS540SH also doesn't pull enormous amounts of Amps. About 7,5 to 8 when stressed for a bit. Biggest advantage: 16000rpm @ 7,4v to the 12000 @ 7,4 v of the 550's. I'm interested to see if it makes a difference. The rpm under load at max efficiency is also higher on the 540, be it that the amps go to about 10.
We'll see.
Edit: Took off the weak iron mantles of the 550’s, and the speed increased by quite a bit. Those mantles are supposed to increase torque at the cost of rpm. I think the 550’s are powerful enough without them. The weird thing is, they run about as long on a 2200mah LiPo as my T90 with the blue-endbell Taigen motors. I guess the 550’s aren’t really stressed at al, and sip amps as a result. Nice!
I'd love to hear more experiences with the standard DKLM gearboxes (Not the fancy one with the separate turning motor) Not a lot of stuff about them on the Web and Youtube. Lots about the fancy ones.
Any of You people use them? What motors? Experiences? Breakages?
Update: By now I have about two hours of running in them. They still perform flawless without their mantles, and have become very silent now they’re properly run-in. The sheer torque forced me to upgrade all the wheels and swing-arms. The plastic idler gave up the ghost first, after that the running wheels became wobbly and squeeky, and the swing arms developed shocking amounts of play... and that after just an hour of running in (admittedly really) rough terrain.
Everything is metal now, except for the chassis and turret. Weighty! Yet, the big 550’s don’t care one bit. Braking, and accellerating now does that great leaning and swaying forward/backward of the real tank. Love it!
They're HUGE! However, I discovered -despite their size- they fit quite nicely in the Plastic Leo 2A6 chassis. it was a bit of an expensive gamble, and I was prepared to having to order the metal tub. But luckily, they -indeed- fit just fine.
There was, however, 'one snag : The casing is a bit concave on the bottom, so, when finally screwed in the tub, the shafts exited at an angle, and the motors looked crooked. In the end I epoxied' a 0.5 mm ring on top of the innermost standoffs in the tub, and hey, presto! Everything lined-up great. Had to cut 4 mm from the back of the battery-compartment, though, because the big motors and their mantle needed that space.
I also epoxied metal bushings around the standoffs, to prevent them from cracking when the screws go in. Added to that I epoxied an ABS-cross-beam on the bottom of the tub to give it a bit more strength. All in all, the gearboxes will fit the plastic tub, but not without a little plastic-surgery..
Everything works fine, the IBU2 isn't bothered in the least by the big 550-motors, that look decidedly like Graupner ECO 600-motors. So their max Amperage will be about 7Amp each.
Thing is.. it's not very fast now. Coming from taigen 1:3 with 25000rpm 490-motors, It even looks anemic. But that suddenly seizes to be a problem when the terrain becomes really rough, and by "really rough" I mean "Rutted and gutted agricultural lands".. The speed remains the same, whatever underground.. nice, impressive even. And the big, blue cooling fins..nice as they look, aren't really necessary. The motors get hand warm in an open tub, and no more than that, so they aren't really stressed..
I'm still a teensy bit bummed by the low speed, so the next things I'm going to test are the well-known Tamiya RS540SH/Johnson540's. I got a drawer full of those beercans.. all brand new.
An RS540SH also doesn't pull enormous amounts of Amps. About 7,5 to 8 when stressed for a bit. Biggest advantage: 16000rpm @ 7,4v to the 12000 @ 7,4 v of the 550's. I'm interested to see if it makes a difference. The rpm under load at max efficiency is also higher on the 540, be it that the amps go to about 10.
We'll see.
Edit: Took off the weak iron mantles of the 550’s, and the speed increased by quite a bit. Those mantles are supposed to increase torque at the cost of rpm. I think the 550’s are powerful enough without them. The weird thing is, they run about as long on a 2200mah LiPo as my T90 with the blue-endbell Taigen motors. I guess the 550’s aren’t really stressed at al, and sip amps as a result. Nice!
I'd love to hear more experiences with the standard DKLM gearboxes (Not the fancy one with the separate turning motor) Not a lot of stuff about them on the Web and Youtube. Lots about the fancy ones.
Any of You people use them? What motors? Experiences? Breakages?
Update: By now I have about two hours of running in them. They still perform flawless without their mantles, and have become very silent now they’re properly run-in. The sheer torque forced me to upgrade all the wheels and swing-arms. The plastic idler gave up the ghost first, after that the running wheels became wobbly and squeeky, and the swing arms developed shocking amounts of play... and that after just an hour of running in (admittedly really) rough terrain.
Everything is metal now, except for the chassis and turret. Weighty! Yet, the big 550’s don’t care one bit. Braking, and accellerating now does that great leaning and swaying forward/backward of the real tank. Love it!