this is a pic of a design idea one of my students did in inventor
Nice work. I like it. You may want to make it smaller though. There is a lot of “empty space” on the bottom plate. If you can remove that from the bottom [and top] you should be able to lose a few ounces. Also have you considered milling out the middle ring that attaches the speed controlers and spikes? We did this last year [something VERY similar] and it will save you weight but only if you have access to a mill. Also you might want plot out where your holes will be on Inventor and punch them, and then mill out large triangles to save some more weight. This can also be done on top.
Check out these links for more information and if you have any questions let me know. I’ll try to post a picture or two of our middle ring that lets us put our speed controllers back to back.
http://www.chiefdelphi.com/media/photos/28671
http://www.chiefdelphi.com/media/photos/28627
Pavan.
Cameron,
What a nice drawing! I normally caution teams on this type of electrical tray design. It is very difficult to troubleshoot and replace defective components. As always, secure the PWM cables near the device they control so that the connectors do not fall out during competition. If we are at the same event, please come and find me so you can show it off. Don’t forget pictures when it is built.
Where’s the big ugly heavy gray thing we’ve all come to love? :rolleyes:
It looks good! How close together are the components from each other? On our electronics board last year, the speed controllers and spikes were a half inch apart, and it was difficult to get the wires on without excessive bending of the wires.
An addition to what Al said, you might want to buy a couple of circular housings for your connectors.
It will make it more organized and if put a male/female to the analog PWM ports and a female/mail to the speed controllers etc., it will make life easier if you have to replace a specific speed controller down the line, a spike, or even the brain. It will make your life much simpler.
Also I suggest having a few “back-to-back” speed controllers ready so that you just have to pop out two-three screws and pop them back in with the new speed controllers and it wills save you the hassle of removing a speed controller and adding one on. I suggest having at least 1 of those arrangements [two speed controllers] for both spikes and victors because you never know when you’ll need it.
~Pavan.
Also I suggest having a few “back-to-back” speed controllers ready so that you just have to pop out two-three screws and pop them back in with the new speed controllers and it wills save you the hassle of removing a speed controller and adding one on. I suggest having at least 1 of those arrangements [two speed controllers] for both spikes and victors because you never know when you’ll need it.
This saved us much grief in Atlanta this year.
Interesting that you mention this, and I agree…of all the design considerations on the electrical component layout, serviceability should be way up at the top. Unfortunately this means it usually ends up taking up a lot of area, and requires also designing the rest of the robot around access to the electronics panel. On the plus side, if you design the robot to be modular, then you can quickly remove whatever might be in the way of the panel, and this modularity can help in other ways. The 1726 robot for 2007 has a quickly removable mast/arm assembly, with a 25 pin connector for all the arm sensor wires, so there is no need to mess with the individual PWM cables when working on it.
It might be helpful to lay out the Spikes and Victors flat, in rows, with the terminals facing the sides, rather than facing each other. Or perhaps the Victors and power distribution components could be on a bottom panel, and have a top hinged panel for the components that use “small” wires, that can be quickly swung out of the way.
In any case, now is the time to be thinking about it and learning how to make the drawings in Inventor, so kudos to 1527!
This is definitely something you want to keep in mind. There needs to be a decent amount of space at the ends of the victors and spikes for the wires, especially depending on what is controlled and hence what gauge wire is used. We had some similar problems laying out our components in physical space - it’s easy to forget about the wires and connectors when dealing with the neat little packages. And as squirrel said, putting the components together with their sides touching is a great way to save space - this is what we did when our failed pneumatically controlled arm had required 7 spikes to operate.
As the previous posters have said, think about the wiring a little bit more before committing to this design.
It might look good on paper, but just looking at your Spike relays, I’m seeing problems. If you’re using the basic crimp on connectors to wire those, the connectors protrude from the connection point another centimeter or two, which will lead to some problems in the current design. You can solve this by rotating the relays all 90 degrees…but things will still be close.
A nice and compact design might look great on paper, but I know from experience what a mess wiring can make when you don’t take it all into account. Nothing’s worse for serviceability than a tangled mess of power and signal cables when you have to run them all in the same little space.
You might be able to make your current board layout work…but just make sure the components are facing the right way, so you can make the wires go where they need to without problems.
As already said, beautiful drawing, but once you try to wire it, you’ll see that it won’t work.
Also, there is an advantage to having the Victors vertical, cooling works better.
The euro connector looks nice & neat, but if you ever had to remove the board, it takes a lot of time to actually undo all those screws. A circular or sub-D connector is fine for signals, but for power you need to use something larger, like the 20/30/45 Amp Anderson Powerpole series (They are all the same connector, the only difference is the size of wire they can hold).
It is good that the Victors are covered a little, as metal shavings and other debris are major failure causes. Keeping wires short helps with weight, more than you think. I don’t see a fuse panel, but there’s room on the top, or underneath the bottom. Don’t be afraid to drill holes for wires, either.
Don
Jim,
There are alternate ways of laying out electrical. We rarely put all of our electrical components in the same area. The power wiring between battery, Victors and motors become shorter when they are placed in such a way in the robot that wiring is more or less straight lines. Think of a star burst with the battery and power distro in the center of the robot (for weight and balance) and then radiating out from there the Victors and motors. In many cases, the motor wires can be attached directly to the speed controllers, eliminating yet another set of connectors and therefore another point of failure. This approach also makes troubleshooting much easier. We also do not use hardware for mounting the speed controllers. Tywraps work great when using a punched aluminum panel for mounting everything.