So for our elevator system we are trying to use the Rev Robotics kit as shown here. This kit requires some special T-Slot extrusions that allow for the bearings to travel smoothly along the stock. We searched far and wide, however, we could not find any stock that is comparable to the one we need.
Is there any other vendor that offers this kind of special stock? Could we technically get away with using normal T-slot extrusions?
This is a great place to get T-Slot Extrusions! It is where my team stocks up every year!
The key is the chamfered surface for the v-bearing to ride in, this cross section has that feature.
https://www.servocity.com/x-rail
https://8020.net/1010-s.html (here is the standard T-Slot) They are also great quality and well priced!
Careful, this doesn’t have the v-grove bearing surface spec…
That is true, but there are some bearings it works with well (in the t-slot)
It sounds as if the OP is looking into an elevator kit. Changing the spec on bearings/t-slot profile could lead to some nasty surprises with mounting or included kit hardware. Not to mention longevity considerations…
There are also around ten different models of T-Slot Extrusion, each with different specs, sizes, types of edges, and colors, on the site if this one does not work for your needs…
If you’re OK with metric, check out the options from Open Builds Parts Store. Everything I’ve bought from them is great quality. In general, the stuff from Misumi is great as well and you have loads of machining options through them, but I don’t believe they have any sort of V slot extrusion profiles.
Also want to point out - Rev’s extrusion is the lightest I found when looking last year. That being said, some “standard” T slot fasteners don’t fit their profiles, and some of those fasteners have benefits over using regular nuts.
We used their elevator system last year and looked, unsuccessfully, for other sources. This appears to be a custom extrusion for rev. Yes, it looks like 80/20, but it’s not.
Fair warning on the elevator: you have to figure out how to do the spool really well. The diameter of the spool gets larger as you put more string on it. And, since you’re using the same spool for both the up and down, the result is that you’re winding string at a somewhat different rate than you’re pulling it off. And, that means that the string gets slack, and the slack string jumps off the pulleys made of v-groove bearings they want you to use. And, that’s not good. We had several instances where the string got stuck and, instead of lifting the elevator up, the pillow block pulled completely out of the extrusion.
If it were me, I’d think about using a continuous chain driven by a sproket instead of trying to spool- and unspool string at the same time.
The Rev lift kit is built specifically to work with the Rev extrusion. I would not suggest trying to use it with 8020 or any other t-slot extrusion profile other than the Rev extrusion. See if any teams in your area may have some Rev extrusion to sell you. Additionally reach out to Rev (@Greg_Needel) to see their upcoming stocking plans for their extrusion
This is what my team did last year, except we had the 80/20 kit instead of the Rev kit. I agree that using chain and sprockets is much better than going with the string and pulley method…
That may be our only options for now. Otherwise we could just cross our fingers and hope that it doesn’t take too long to assemble the elevator system once we revive the extrusions.