Captainowie Posted January 21, 2015 Posted January 21, 2015 your best bet is to try That's kind of what I was trying to get at, but for some reason couldn't get the right words down. If you find that one box doesn't suffice (I don't mean to imply that Milan will be wrong, but the possibility is there - if the car is geared to go fast, then the current drawn during acceleration might get too much), then I would suggest each driving motor be powered by its own battery box, with the other stuff spread evenly across the two boxes. The reason is that two heavily loaded L/XL motors don't draw that much less current than two heavily loaded L/XL motors plus a bunch of other lightly loaded stuff, so if you're breaking the limit on the latter, you'll probably also break the limit on the former. On the other hand, if it's only juuuust not making it with one battery box, you might be able to get away with one AA battery box for driving and a smaller one (rechargeable, or AAA or similar) for the other bits. But again, you will need to see for yourself what actually works. Good luck! Owen. Quote
Jim Posted January 21, 2015 Author Posted January 21, 2015 That's kind of what I was trying to get at, but for some reason couldn't get the right words down. I did understand you Indeed I will do some testing, with different setups. The rechargeable battery boxes can be fitted nicely on each side. Probably a bit easier than the normal battery boxes, but that's something I need to try as well. Maybe the regular battery boxes will fit nicely between the beams. Quote
PKW Posted January 21, 2015 Posted January 21, 2015 I'finding some problem using one RC motor and The servo motor in The same receiver Due To The constantely use of power of The servo Electronic, But the motor has an high load so io You Wang to put 2L motors with an high load and only one lipo box you'll have Little bit more power if You don't put servo and motors To The same receiver (V2) Quote
Jim Posted January 21, 2015 Author Posted January 21, 2015 I just tested the setup with two L-motors. In all cases the drive shaft ends with a 12T bevel gear driving the 20T bevel gear, which drives the Diff. As you can see in the picture below. The pictures shows a WIP for setup 5 by the way. Another important detail; this setup is tested with the minimal chassis. The weight will have increased drastically when the car's finished. 1. Using two 20T bevel gear on the motors and one 12T bevel in the middle This worked pretty well, except when you start driving the gears grind. Obviously due to the force which need to be applied to get the car moving. Once it's moving it works fine. Driving backwards doesn't grind the gears and works fine. 2. Using two 12T bevel gear on the motors and one 20T bevel in the middle This prevents the gears from grinding. However, the cars drives a bit wobbly....slow....fast....slow....fast. It seems when the car is in the "slow" mode it is building up force to push the car forward. I reckon this is putting a lot of strain on the axles? When there's enough force, the energy is released and the car goes to "fast" mode. This motion repeats over time. Does this make sense? 3. Using two 16T gears on the motors and one 16T gear in the middle. I actually forgot to test this. 4. Using a single XL motor directly connected to the drive shaft A bit of teeth grinding and wobbly (slow, fast, slow, fast) driving in both directions. Taking a closer look; the gear grinding was caused because the gear slipped from his axle a bit. Not sure whether this was the case with the L motors as well. 5. Using two XL motors with 36T bevel gears and 12T bevel gears (Bruno's Ferrari setup) Not tested yet. I guess most of you Pro's will recognize my problems and think "been there, tried that" Any thougts or insights are more than welcome. For example; Are bevel gears more "grind prone" than normal gears? Quote
Milan Posted January 21, 2015 Posted January 21, 2015 If it is grinding at any stage of the building, its not good. All the gears should be braced so that car hit the wall, either motors should stop, or tires should continue spinning. Which gears are grinding? Quote
Jim Posted January 22, 2015 Author Posted January 22, 2015 Af far as I can see the ones near the diff. The 12T can easily slip from the axle. I probably need to find a solution for that. I can simply power the axle with the 20T gear. I will try that first. Then I can better determine whether it's still slipping. Using two L motors would be the best option to fill the gaps within the chassis. Quote
Milan Posted January 22, 2015 Posted January 22, 2015 I would suggest then to move that pair of gears in front of the 5x7 box, reinforce it from both front and back (cos thats causing grinding), and to add another 20 teeth gear inside the 5x7 box that will power the diff. This is easy in theory, it remains to be seen in practice. Quote
Jim Posted January 22, 2015 Author Posted January 22, 2015 I would suggest then to move that pair of gears in front of the 5x7 box, reinforce it from both front and back (cos thats causing grinding), and to add another 20 teeth gear inside the 5x7 box that will power the diff. This is easy in theory, it remains to be seen in practice. That's is exactly what I had in mind It's definitely better, but the question is....is it good enough. I don't MOC a lot (you don't say), so this is very educational for me! Quote
DarkShadow73 Posted January 23, 2015 Posted January 23, 2015 (edited) Funny, I've been waiting for the 42039, but maybe it hasn't been released in the USA yet? Many times TRU has a lot of sets available right before Xmas, but so far it isn't even on the their website here. EDIT: Upon checking Brickset, I see according to their info, 42039 hasn't been released in US or Canada yet. At least we got most of the 1H2014 sets on time, instead of waiting until summer like last year. I just tested the setup with two L-motors. In all cases the drive shaft ends with a 12T bevel gear driving the 20T bevel gear, which drives the Diff. As you can see in the picture below. The pictures shows a WIP for setup 5 by the way. Another important detail; this setup is tested with the minimal chassis. The weight will have increased drastically when the car's finished. 1. Using two 20T bevel gear on the motors and one 12T bevel in the middle This worked pretty well, except when you start driving the gears grind. Obviously due to the force which need to be applied to get the car moving. Once it's moving it works fine. Driving backwards doesn't grind the gears and works fine. 2. Using two 12T bevel gear on the motors and one 20T bevel in the middle This prevents the gears from grinding. However, the cars drives a bit wobbly....slow....fast....slow....fast. It seems when the car is in the "slow" mode it is building up force to push the car forward. I reckon this is putting a lot of strain on the axles? When there's enough force, the energy is released and the car goes to "fast" mode. This motion repeats over time. Does this make sense? 3. Using two 16T gears on the motors and one 16T gear in the middle. I actually forgot to test this. 4. Using a single XL motor directly connected to the drive shaft A bit of teeth grinding and wobbly (slow, fast, slow, fast) driving in both directions. Taking a closer look; the gear grinding was caused because the gear slipped from his axle a bit. Not sure whether this was the case with the L motors as well. 5. Using two XL motors with 36T bevel gears and 12T bevel gears (Bruno's Ferrari setup) Not tested yet. I guess most of you Pro's will recognize my problems and think "been there, tried that" Any thougts or insights are more than welcome. For example; Are bevel gears more "grind prone" than normal gears? Just a thought on gears, in most cases I've found that bevel gear against bevel (mainly 12T bevel against 20T bevel, or 20 against 20 or 12 against 12) tends to produce more noise, and grinding noise than standard (16T) gear against another standard or a 16T dk gray clutch gear. That's been my experience over the years. The old 8T gears we're much more prone to slippage, therefore grinding than the newer, reinforced style. Just my .02 worth...I've never had much problems with single bevel against single bevel. Edited January 23, 2015 by DarkShadow73 Quote
Corvette3 Posted January 23, 2015 Posted January 23, 2015 I had a quick question about that render, why does the L motor look so strange? Sorry if i sound stupid or something. Quote
Rishab N Posted January 23, 2015 Posted January 23, 2015 L motors and servos aren't available in LDD so the motor is a mock up that is the same size Quote
BusterHaus Posted January 23, 2015 Posted January 23, 2015 I'm late to this party, but a while ago I made a video which partially answers the question of having two hard coupled motors: Regular DC Motors don't have the same acceleration and deceleration, and their speed probably varies. I would consider this solution acceptable for MOCs that don't get much play, but if you were to run a mechanism with frequent start/stop cycles for a prolonged period of time, it will affect the lifespan of the motor(s). Quote
Jim Posted January 23, 2015 Author Posted January 23, 2015 Just a thought on gears, in most cases I've found that bevel gear against bevel (mainly 12T bevel against 20T bevel, or 20 against 20 or 12 against 12) tends to produce more noise, and grinding noise than standard (16T) gear against another standard or a 16T dk gray clutch gear. That's been my experience over the years. The old 8T gears we're much more prone to slippage, therefore grinding than the newer, reinforced style. Just my .02 worth...I've never had much problems with single bevel against single bevel. I will try a setup with 16T gears as well, thanks! I'm late to this party, but a while ago I made a video which partially answers the question of having two hard coupled motors: There no such thing as too late. Thanks for the information. You've given me a great idea.....EV42039 Quote
SilenWin Posted January 24, 2015 Posted January 24, 2015 (edited) Hi there! I just finished motorization, and I must say that this set is just perfect. All electrics can be placed very tight, the exterior has not changed (just a couple of panels added). I used two buggy motors for drive, servo for steering and two M-motors to the other functions. I also used two LiPo batteries and SBrick. Model reaches acceptable speed and well controlled. Video is coming soon. Edited January 24, 2015 by SilenWin Quote
Jim Posted January 24, 2015 Author Posted January 24, 2015 Nice work. Looking forward to the video Quote
SilenWin Posted January 24, 2015 Posted January 24, 2015 Nice work. Looking forward to the video Thanks! Now I'm choosing between two gear ratios: 1:2,3 vs 1:3,9 (gears safety vs fun) Quote
Omikron Posted January 24, 2015 Posted January 24, 2015 Thanks! Now I'm choosing between two gear ratios: 1:2,3 vs 1:3,9 (gears safety vs fun) Why not both? Quote
SilenWin Posted January 24, 2015 Posted January 24, 2015 Why not both? If I add the gearbox, then I'll have to sacrifice one of the main functions =) Quote
Omikron Posted January 24, 2015 Posted January 24, 2015 If I add the gearbox, then I'll have to sacrifice one of the main functions =) I meant why not film both versions? Quote
SilenWin Posted January 24, 2015 Posted January 24, 2015 I meant why not film both versions? Because gear changing is a bit difficult) Making outdoor video with two gear options will take two days. Quote
Omikron Posted January 24, 2015 Posted January 24, 2015 (edited) Well do you know the saying : "A smooth sea never made a skillful sailor" ? I hope it's easier to choose now. Edited January 24, 2015 by Omikron Quote
SilenWin Posted January 24, 2015 Posted January 24, 2015 Well do you know the saying : "A smooth sea never made a skillful sailor" ? I hope it's easier to choose now. I think that easier way is change the car's rear part to make the process of gear changing more friendly :) Quote
Jim Posted January 25, 2015 Author Posted January 25, 2015 Great performance! I need to consider RC motors too. Quote
SilenWin Posted January 25, 2015 Posted January 25, 2015 Great performance! I need to consider RC motors too. Thanks! I think that RC motors fits perfectly. They could drive this car (1,68 kg) even with direct drive (not count differential gearing). Quote
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