One of our fall training projects will be a swerve drive base. We would like to try building the frame out of 80/20 or some similar t-slot material, since we have never used it before and would like to try new things for the this project.
Questions:
I spoke to Misumi USA at Houston, and I know that they sell the material, but I lost their contact info. Navigating their website hasn’t thus far turned up the material. Anyone have contact with them?
What suppliers do those of you who use extruded aluminum like to purchase from? I want to try Misumi but am open to any.
What material profiles work well?
What fasteners tend to be the most universally useful?
I won’t be too much help with your other questions, as my team doesn’t use T slot. We were considering it a few years ago, but ended up going towards plain aluminum tubing with polycarbonate gusset plates.
+1 to REV extrusion. Have worked with both 80/20 and REV and the REV extrusion is just as good, about the same price, and uses hardware you probably already own.
That being said, my team is much happier since we have realized that 80/20 and REV extrusion are for prototyping chassises (what’s the plural of chassis?) and the final chassis should be made out of rectangular extrusion and/or sheet metal. You’ll save yourself a lot of headache with having to ensure the bolts stay tight and everything stays square. And if you want to make any precision holes or tight-tolerance chain/belts, you’ll need some divine intervention. This isn’t to say that there’s no place for these extrusions on your robot, just that you’re probably better off not making your chassis from them.
Please don’t use something like 80/20 on a drive base. Superstructure is okay most of the time, but every-time I’ve used the stuff on a drivetrain it is a constant battle of adjustments and checking to make sure nothing has moved. If it really is just a prototype, thats one thing. But if you actually plan to build a useful robot on top make it out of something else.
I’d be careful building a drivetrain from T-Slot. Unless you really gusset/bracket it well, it has a tendency to rack and could cause alignment issues. Not to say you shouldn’t try it, just a warning.
We use OnlineMetals for our extrusions. They don’t have T-Slot unfortunately, but they have just about anything else you could want.
This is entirely the right attitude to have. TSlot is all good for things you plan on adjusting regularly, or to prove a prototype.
But, I’d ask the question of diminishing returns: If the cost of box extrusion and some simple gussets/brackets is lower than TSlot and associated hardware, why not just go with that?
For other brands of TSlot, also check out OpenBuilds, and the various Chinese equivalents.
80/20 holds adjustment pretty well if you use adequate gussets and torque the fasteners properly. Once we are sure of position we loctite the fasteners, It is a good choice for an off season drive base prototype. 80/20 will give a substantial educational discount. I have received it both working through a distributor and calling them directly. You have to ask for it every time you buy something so it is best to start with a fairly complete list.
Thanks everyone, I’m gonna contact REV about their options. We are only using it as a test base for swerve modules, and it will not be used for a competition base. We want to be able to adjust the geometry to understand more about how to optimize a swerve base, without committing to any particular arrangement by welding or riveting the frame.
Agree, great for superstructure, would not prefer it on drive train. The KOP drive base can mated with 80/20 pretty easily.
We had a supplier that let us have “scratch n dent” stock at a very low price. We also bought the button head hex bolts from McMaster, much cheaper. Yes, gussets and brackets are expensive. But unless you mod them they are a long term “capital” expense that you will use and reuse for a long time.
It enabled us to step up to a two robot build.
There is some tendency for bolts to work loose in places. Just add a once over to the pit routine.
The stuff is a bit heavy compared to tube but we like it.
We used 80/20 our first year… hardware was expensive as noted in previous post…
Second year we started with REV, love the fact that we could leverage the #10 hardware… very cost efficient…
We are redoing our pit, workbenches and cart… we will be using Tslots… they are giving 50% off their price list to any FRC team and shipping is free once a month.
There is a seller on eBay that goes by the name of 8020inc. There is at least one other vendor of similar stuff (don’t know if they are a re-seller). Make sure you are not going to get killed on the shipping though. There used to be a vendor on eBay that was a knock-off of 80/20 but I don’t see them anymore.
Check around the scrap metal yards in your area. I have seen industrial workbenches made from 80/20 at scrap yards in the past. You would have to check to make sure that the pieces are straight enough for your application.
80/20 has nice material in metric and SAE (standard) sized hardware.
I like to avoid metric because every now and then a student will crank on a metric bolt in the wrong place and destroy something.
You can use 1/4" bolts and washers to lock things down, but these need to be fed from the ends (slide in). That is ok, if you plan everything out ahead of time. If not you are better off with twist and lock fittings that can be inserted (drop in )anywhere. These are the things that can get expensive. https://www.8020.net/
