Wood electric brew stand concept

I drew this up in SketchUp, as a plan for my brewstand, and I am looking for some input. It is constructed of 4x4's, 2x4's and some plywood. I'm also going to put some casters on the bottom. I decided to go with a two tier setup, so that I will only need to use one pump, and I also wanted everything at eye level or below, so the MLT tier is low. I am also not sure what kind of casters to use, if anyone has any suggestions that would be fantastic.

Stand looks good. I used some 3" casters from home depot. I would also raise your mlt a couple of inches above you pump so you will have a easier time priming the pump.

I like it. Looks like you have room to put some cabinet doors and shelves on there too. I think I would raise the MLT tun to have room for the pump and maybe a rims tube. Easy access but out of sight for a clean look.

don't forget to account for the casters in the overall height.

i might make both pedestals the same dimensions (21" x 21") so you can move things around or change vessels for bigger batches without having to re-engineer.

definitely move the MLT up a bit so you can get a prime on the pump, perhaps the top of the cooler just under the top of the pedestals. that extra space can be used to hold hoses, etc.

i would put a diagonal 2x4 on each pedestal back and one on each side to keep things square.

pick a spot for your mash paddle to hang

After looking a little more, I think you have some structural issues. Not hard to fix.

Move your vertical 2x4s so they are right above and below the framing. Orient them so both frame pieces in each corner are supported. You don't want to rely on screws or nails to hold the weight.

You also have some twist issues with the towers for the BK and HLT. I think a shelf would help but if you can face them in plywood, they would he really strong.

Lastly, you need to add some support between the towers in the front.

I'll draw it up in Sketchup for you.

4x4 vertical members look like WAY overkill to me for the load they will be carrying - and, they add to the weight of the stand. 2X4's like in the above drawing are plenty strong enough IMHO.

I agree with the others regarding the height of the MLT being a bit above the pump for priming reasons.

Ok, I drew it up again from scratch ... I currently am not able to work on it and have quite a bit of free time, so I can keep drawing it up as many times as possible.

I replaced the 4x4's with 2x4's, and I think the way I designed it, it should pre pretty rock solid. I didnt know how to draw diagonal 2x4's in sketchup, so I went with plywood. I also raised the MLT up high enough to put the march pump underneath it, however it should prime just fine in the old position because the water level would have been above the pump inlet, right?

It seemed like it would be more stable if the pedestal supports had a collar around them and the flat of the pedestal on top of that. If that isn't true, and I will need more support/stability I will rework it, although it seems like it will be very stable, especially if you look at the image of the bottom.

Is there anything wrong with using large framing screws to put this together? I have a nice drill, but no nail gun ... so screws seem like the easiest assembly solution.

Here is version 2.0:
Front:

Bottom:

And here it is with no vessels:

I always pick screws over nails. I made my wood stand out of 2 x 6 and lagers bolted everything together.