Sir_Samsalot

@nicjasno Ah, I hadn't even considered that the bricks were a cause of stress. I'll try using liftarms instead. As for the bogey, I did unfortunately run out of the right parts (I suppose I could try to buy some online or something). And yeah, I know the setup takes up tons of unnecessary space (like I said, WIP), but most of the gears are there because of the 4-speed gearbox, where I still have yet to build the parts that actually control the gears (I'm thinking about a setup similar to this , but have yet to figure out the logistics). Also, only one of the bogies is controlled by the gears; the other is a PF train motor. I'm trying to gear it in a way that the two motor speeds can be as close as possible. I might just have to scrap that idea though, and do the two bogies thing you suggested.Thank you for your input. @Epic Technic Well, looks like I'll probably have to scrap most or all of my bricks in favor of liftarms. Maybe I'll just do a full redesign, so I can work on better weight distribution. And that bevel is completely gone now. It was just too loose to work with. Thanks for the advice.

Hello all. It's been quite a while since I last posted anything here (got too busy for legos, sadly). However, recently I have been working on an MOC for a train (Correct me if I'm wrong, but this seems like the correct forum since I'm just asking about gear issues), and have run into a few problems: Here we have the train, without its cover. Nothing pretty here, just something thrown together to see if my ideas were even possible. The train is powered by one XL motor (attached by rubber bands to hold it in place), which is fed into Sariel's lovely 4-speed linear gearbox (http://sariel.pl/201...linear-gearbox/), after which power is geared up into the wheels. The main problem is the evident flimsiness of the whole setup (don't worry, it's still a WIP). The front wheels are not attached on well, the front needs more weight (though pushing down on the front doesn't entirely solve the problem), the middle needs more support (shouldn't be a problem after the case is finished), and despite my attempts to fix these problems, the gears constantly lock up and the train can only seem to move a few inches at a time before I shut it off in fear of motor damage. Evidently, gears are not my forte. So before I attempt to dive into this mess again and screw something up, I wanted to get suggestions from all of you people on where my problem area is and what I should do to fix it. But first, here are a few more pictures: A close-up on the rubber-banded motor. The bands aren't completely tight, so the motor probably pops out a little when everything locks up. Likely problem spot #1: The bevel connecting to the front wheels. The way it's set up, the entire front wheel assembly ends up spinning with the wheels. Not a good sign. Likely problem spot #2: The actual front wheel assembly. I tried to make it as efficient with my limited collection of parts, and this was the best I could make. Well, there you go. Hopefully I can get a suggestion on where to start with this thing, so I can get to actually finishing it Thank you! EDIT: I have narrowed down the issue to being the bevel gear, which was far too weak to handle the power I was giving it. Also, the motor seems to require stronger rubber bands, as it's really starting to slip now on the higher gears. Guess I should've done more experimentation before making this post . Oh well, I'm still open to suggestions for how to improve this thing's stability and reliability, not to mention its strength. Any ideas?

Thank you for all of the replies. I figured I would end up having to redesign the majority of it (lesson learned: lack of planning = huge mess). Also, to dhc6twinotter, I am using two different speeds because the mechanism will be lifting a large variety of weights, from very heavy to relatively light (If you can call lifting a Mindstorms brick and a few motors light), so I wanted to try and replace some of the unnecessary torque with a bit of speed (for efficiency's sake) for the lighter loads. Edit: Since my application for the transmission will not involve changing speeds under excessive load, I'll probably work with your 1st option. Thank you for all of the suggestions.

Hello again. Many of you will probably remember me from a post I made about a week and a half ago asking for help for a pulley system of my automated warehouse machine. Well, since then, I've attached four separate pulleys to the main transporter and I've been hard at work designing the entire pulley mechanism / horizontal transporter. Allow me to introduce you to this monster: As you can see, I have a serious overengineering problem. Anyway, the device features a total of 8 separate pulleys, arranged in 4 groups of 2. Things were going perfectly well until I realized that my 1:72 gear ratio (I've been trying to allow the system as much torque as possible) is, as you might guess, incredibly slow. I then got the idea for a 2-speed transmission, one at 1:72 and the other at ~1:14, which would be controlled by another PF motor to keep the system automated. Here are a few pictures of the transmission area: This is a bottom view. The moving section is the two white 9-stud connectors and everything attached to them. This picture shows the way that I intend to control the transmission with a motor (The PF motor will be put in the spot where the black gear is). Here is a top-down picture that shows how the moving part connects to the gear box. You can barely see the two white connectors buried beneath everything else. So this is all working perfectly well, except for one major flaw. Here's the problem area in question: The problem lies with the two 24-tooth gears that are connected to the worm gears. Both 24-tooths unfortunately lie on the only two moving axles in my transmission, and both gears have no room to move left or right without sliding on the axle. Because of this, the only way to change speeds means pushing hard enough on the axles themselves to slide the two problem gears back and forth. This requires too much force for my transmission to handle using the motor setup, and the whole setup is extremely awkward and clumsy even if I manually push both axles. Even worse, the only way I can see to fix this flaw is to redesign most of the gearbox. However, since every section of the machine is packed together and thus intricately connected, I would have to tear most of the setup apart just to gain access to the gearbox, and even then I don't have very much wiggle room because of the lack of space. Do any of you have any better suggestions, and if I do have to redesign the gearbox, do you have any suggestions on the best design I could use to avoid this mess again? Any ideas are greatly appreciated.

Just found out about this myself, love the idea! Put me in for Peoria, Arizona, USA!

Okay, thank you.

Alright, thanks for clarifying. What if I tried using my PF motors (since I have more of them) to increase the crane's speed, and then connected the motors to my Mindstorms brick with a setup like this: My only worry with this setup is slow response times. What do you think?

Hi, I'm not entirely sure what you mean. Are you suggesting a single NXT motor with four pulleys connected to it, or four NXT motors each with their own pulley?

Hello. Before I begin, I want to warn you that this is my first post. Also, this is my first time of really getting into MOCs with Technic/Mindstorms, so I'm not very well acquainted with a lot of the mechanical aspects like torque and gear ratios. I apologize for this beforehand. Apologies aside, I present to you my incredibly-unfinished WIP automated warehouse system, inspired by this setup: Unfortunately, I only have the transporter built that will transfer things from the loading/unloading area to the actual storage area. Here's some pictures: Perspective view Side view Bottom view Demonstration of the transporter's "grabbing" mechanism I built this section without very many issues, until a major problem ground the project to a halt: Developing a pulley system strong enough to lift the machine and its cargo. My current plan is to use either a two-pulley or four-pulley system that connects to both sides of the transporter, although (as I mentioned at the beginning), I am not very well-acquainted with torque, gear ratios, etc. So, I turn to you all for help: How would you go about designing a pulley system to lift the most weight possible? Any tips for minimizing weight on the actual machine itself? I'm also open to any suggestions for the project as a whole. Also, since materials are likely to be an issue, here's another picture of the motors and large gears that I own that are not currently in use on the transporter. (I know, it's a tiny amount of stuff, but I have some money to spare to buy extra gears and motors where needed) Thank you!