mdemerchant

From the way you originally said it, it implied the wheel only spins in one direction. Which would be kind of magic. But you meant it turns in one axis and slides in the other axis like any low friction wheel does.

Project looks good so far. It's an ambitious number of functions to pack into the scale, especially with pneumatics. One minor comment, I don't think bulldozers have steering wheels as a general rule. I can't think of any tracked construction vehicle I've ever seen that does have one. Maybe you could do two levers driven off the tracks with really weak clutches, that would look kind of realistic when the tracks are driven.

I learned recently when we had a photographer in doing a product shoot that they way the pros achieve this is by shooting a bunch of images with narrow depth of field at different focal depths and combining them in photoshop or whatever editor of choice. It's called focus stacking. You need a proper camera, which you have, a tripod, which I assume you have, and it's more work but it will give you crystal clear depth of field as deep as you like with any lens and aperture.

That's an impressive model with a lot of nice details and the functions seem to work well. It's too bad there is not a smaller bucket you could use to make the wheel more realistic. Why does the real machine have all those cranes? Just for maintenance?

Nice job. It should be more accessible in this size for more people to build. You even have a tiny operators cab. You are missing the box for the chain to pile into though. Do they use that on all the sizes of SK cranes or only the biggest ones?

I'm fine with a big model costing more than that. But I think it probably strongly depends what kind of MOCs you buy and why. In my case, the ones I buy are almost always fairly large/complex things I want for display pieces in which case I'm going to order typically hundreds of dollars of parts for them anyway so the instruction cost is not that significant. But if you are looking to buy MOCs just for something to build with your parts you have then I can see you will be more concerned about the price. I rarely do that because if I just want to build something I'll just build something myself most of the time.

Wow, all of the examples all of you gave are very reasonably priced and so few takers. @M_longer, your Volvo is a great model and it got plenty of views, around 4500. I'm shocked it has so few purchases. I have only a couple of free MOCs posted and they both have thousands of downloads, one has nearly 14000. Around half the people that view them download them, versus less than 0.5% for the Volvo. I was quite sure that having a price versus free will obviously greatly reduce the number of people who get the model but I never would have imagined it could be by 100x and for one of the most popular MOCers on Rebrickable. I wonder what happens if you just charge some nominal amount like 1 euro. Maybe there's a magic price point that can drive volume, even though it seems unreasonably low given the quality/complexity of the MOC.

This is an interesting point. What is the actual mechanism by which you get paid through Rebrickable? I have only posted a couple of MOCs for free so I never really thought about it. But I always assumed money would get directed to you minus some sorts of fees from RB and whoever else may be involved in handling the payment so you collect less per sale than the listed sale price. But your comment kind of implies you have some fixed overhead cost just from being setup to sell MOCs. If you run you own website I get it but does RB work that way?

Your question kind of got lost in the other discussions but here is my two cents. The gearing is probably the major problem with responsiveness, not the U-joints. Consider that 270 degree rotation of the worm gear will only turn the 16T gear 3/4 of a tooth. This magnifies all the slack in the system and is going to make the steering super slow even with no slack at all. You will be much better off to find a more direct routing of the steering and use closer to 1:1 gearing assuming this is a non-RC model. If you really can't avoid sending the steering sideways it would be better to use a chain or even a bunch of 16T gears in a row rather than sticking in a worm gear to turn the transmission axis and U-joints to turn it back. If you really, really have the turn the axis then use some bevel gears instead of the worm gear.

This looks great, really well done. I like that it has a few functions that are beyond the standard 4 function loader. My current project also happens to be a loader but I can safely say it's unlikely to look nearly as impressive as this one.

Yes, it is too wide for scale by quite a bit. Those tires look good but from the video they seem really soft. Do you think they will be able to support heavy models like this or your Grove? I guess the weight is distributed over a lot of tires, maybe ok. I did not make a video originally and my crane has been disassembled for a few years so I can't make one easily now. @seregiz and @nigel1975 both took some awesome photos of theirs but told me it was too large for them to easily make videos.

They are certainly going to make the build much quicker which is good if you are the sort that really gets bothered by repetitive building. I think the resulting structure is probably also a fair bit stronger than most built up 7x7 lattice booms, mainly because they have cross bracing in both directions where most people build those booms with two flat lattices just connected by axles so they are flimsy in one axis. I don't have the parts though so can't say for sure but in looking at how they are assembled they must be stronger. I think the main limitation is they only work well for a 7x7 cross section. If that's what you need for your crane, great, but if you are interested in making something closer to scale most cranes don't have booms with square cross sections and don't use a fixed cross section for boom, jib and derrick. So I don't think the parts are as flexible in their application as they ideally would have been.

Great choice but that's the one PU set I own so I don't need a conversion Although I did convert it to C+ full RC after I was done playing with my 42100. Unfortunately I don't have a complete design file for it or I would post it. Doing the conversion of the original set should be pretty straightforward, only one motor to deal with and it's got space. Now I feel like building Big Red again... such a good set.

No, actually I find it easier to thread through things because it's thinner but stiffer. It's not really that prone to tangling, just more so than the Lego string which is nearly impossible to tangle. If you throw several meters of the Kevlar in a heap on the floor and then wind it up you are likely to come across a small tangle while winding but it isn't prone to tying itself in real knots.

It's also just using the tilt reading from the hub but the linkage makes the hub tilt more than the rest of the superstructure does. The control may be slightly more complicated/less good with the load sensor because you can't just control it to have zero tilt. You probably need to have just open loop control based on the sensor reading and some math. But if you just put the hub in the superstructure and use tilt I'd be worried about it having very little precision and the counterweight position constantly hunting all over the place. I guess you can put some coding in the control loop to minimize that.