Posted August 18, 20213 yr * I don't know when this moc will finish. I don't have plan to build to real in now except very few part for work testing. We did TC20, with remake studed set to studless. But, how about reverse? Studless to studed. Some rule also will reversed. Like electronic permitted in here. I select 42070 for reverse tc20. Because this set is 40th anniversery model of technic. I set to limit to use part before 1997 except tire and color. because 24t clutch gear came in 1997 and changeover catch came in 1996.. Planned function Wired remote controll using poll reverser switch and 2 motor like 8082's controller(maybe 2 43362 or 1 43362 and 1 2838.) 6x6 drive with steering with central differential and portal axle Both rear axle has simple pendular suspension Outrigger with worm gear(cause no linear in past) Crane rotaion with worm gear Crane rase/lower with worm gear(cause no linear in past) Winch on crane with worm gear secret function Use all gear(8, 16, 16 clutch, 24, 24 crown, 24 clutch, 40(this will removed if not good), worm) Edited August 18, 20213 yr by msk6003
August 18, 20213 yr Which motors are you going to use? The old ones (1997 and before) were pretty weak and of course there was no return to center for steering control, so I'm curious how you're going to solve these issues. Interesting project though, I'll be following this!
August 18, 20213 yr 13 minutes ago, howitzer said: Which motors are you going to use? The old ones (1997 and before) were pretty weak and of course there was no return to center for steering control 42070 doesn't have that either.
August 18, 20213 yr 14 minutes ago, Maaboo35 said: 42070 doesn't have that either. It doesn't have the servo motor? That's pretty strange considering the servo had been available for ages before that set came out...
August 18, 20213 yr 13 minutes ago, howitzer said: It doesn't have the servo motor? That's pretty strange considering the servo had been available for ages before that set came out... Nope. It uses an M-motor for steering when it's in drive mode.
August 18, 20213 yr 2 hours ago, howitzer said: Which motors are you going to use? The old ones (1997 and before) were pretty weak and of course there was no return to center for steering control, so I'm curious how you're going to solve these issues. Interesting project though, I'll be following this! 42070 had no return to center either - it used a M motor and a worm gear? to steer. And it had a clutch gear in the mechanism. You could "steer" infinitely.
August 18, 20213 yr Interesting concept. But those wheels look so out of place. I would use the old hard foam wheels instead and maybe scale it down just a tad if they look small.
August 19, 20213 yr 9 hours ago, GTS said: 42070 had no return to center either - it used a M motor and a worm gear? to steer. And it had a clutch gear in the mechanism. You could "steer" infinitely. Okay, that's funny way to build a steering mechanism. Anyway, what about the drive motors? The PF XL which this uses for driving has some 4-5 times the power compared to 71427 motor which was released in 1997 so it'll be hard to replace the PF motor with anything from 1997 or earlier...
August 19, 20213 yr Author 8 hours ago, LvdH said: Interesting concept. But those wheels look so out of place. I would use the old hard foam wheels instead and maybe scale it down just a tad if they look small. Considering to steering system combind with driving with portal axle this tire size is better. 22 minutes ago, howitzer said: Okay, that's funny way to build a steering mechanism. Anyway, what about the drive motors? The PF XL which this uses for driving has some 4-5 times the power compared to 71427 motor which was released in 1997 so it'll be hard to replace the PF motor with anything from 1997 or earlier... Because that, I did enormous gear reduction before wheel. original 42070's gear ratio of drivetrain is 4.2:1 but I did 27:1(2 old 4L differential meshed with 8t and 1:3 in portal axle.)
August 19, 20213 yr 42070 uses m-motor for steering because in another mode the motor is used to drive other functions of the model. As for motors, the 4x4 stud ones released in 97 with the barcode truck are about the worst ever! They may be efficient using very little power, but their total mechanical power output is really bad. But I find the older early 90s 5x4 9v ungeared motor  has around the same mechanical power output as a PF M-motor when geared down to roughly the same speed. So 2 of them may well produce roughly the same power as an XL if done efficiently, so no worm gears as they are very inefficient, or bevel gears. Use spur gears only and maybe a belt drive at the first stage if it's too noisy, but not too tight as that will increase friction. But 1:27 is not a big reduction with these motors. Also beware that the older drive rings appear to be less efficient than the newer ones because the older ones have slightly wedge shaped dog teeth, which pushes the gears out from the drive ring when under load, causing friction against the surrounding frame work. The newer ones have totally straight dog teeth.
August 19, 20213 yr Interesting project. Are you going to do all the bodywork with system bricks/plates/tiles ? Is there any chance of switching the wheels and tyres? If you’re doing retro it would look so much more authentic with older tyres
August 22, 20213 yr Author Progress 1 Crane base and transmission system is installed. Transmission setup is same with original model. It has first transmission it devide drive with other and other function is controlled by second transmission. All transmission system and crane is tested in real life. Drive setup Only front portal axle and steering is tested in real life. Steering setup I need to brace final gear Crane turning setup Winch setup Outrigger setup Need to make outrigger now. Crane lifting setup Current setup is to much slow so I considering flipping differential. All gear setup
August 23, 20213 yr 11 hours ago, skaah said: You're missing a lot of the vertical 6L beams for bracing, those are a classic. Yes you’ll need some vertical liftarms to brace your structure. You can’t rely on clutch power of the bricks alone
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