Teams have been having difficulty with the linear slides such as the plastic parts stripping, bending, not being stable enough, the plastic outer slide trucks snapping off the metal slide, combining to the point where many people prefer the old slides. Therefore, I propose the fallowing improvements to the plastic part of the slide.
Inner plastic slides only. Outer ones are too weak.
Instead of 8-32 self tapping, using the 6-32 self-aligning built in thread like racks have.
Instead of 2" segments, sell them in long sections to be cut as the builder chooses.
Thanks, I know there is the whole HS-shaft thing, but I hope Vex has time for this!
Somewhat this. It would be nice, but I know this might not be economically feasible for VEX. I’m okay with using multiple blocks and just cutting the last one to whatever length needed.
This would be amazing. It would still allow for not needing a nut on the other side, but would be much more reliable then the self-tapping holes. It would also make the blocks easier to align straight on the slide/metal that you’re fastening it to.
If the 6-32 built in thread isnt an option, perhaps the square profile could be added to the back side like the bearing flats have to it is at least easier to ensure that the blocks are straight when you mount them. Right now you have to tighten and loosen them over and over to get them as straight as possible on the slide, which is difficult with the self-tapping holes.
I know VEX usually releases new parts at the World Championship, but knowing how many teams will probably be purchasing linear motion kits, I think it would be a great investment for VEX to update the kit with these or similar changes. It would improve the performance greatly.
I must propose that the alignment structure, like the black derlin blocks, be added to the green slides. It is very hard to perfectly align two pieces of derlin slides and they hardly stay stable. The black derlin blocks have designs that will keep the block snapped to the square holes, and green slide sections should have them also.
For now, I think it would be hugely helpful if VEX sells just the inner slides individually, that way there is no need for a new design or new molds, just some different packaging.
For the future, I would hope to see linear slides that are not only easier to install, stronger, and aligned better, but also lighter! These things are heavy, and I’d presume the old ones are even worse.
The linear slide is one of the oldest pieces of vex. As nice as it is to see improvement, individual parts for sale would be great for teams with a budget. This will be my first year playing with the new linear slides and hopefully i can work out all the kinks and problems that people have and make them efficient.
My team has always been scared of the slides because they just seem to bend too much, no matter what we try to do. The bending problem seems to compound as the slides get longer - I doubt we’ll see many lifts try to use these because of the bending.
I’ve used linear slides on a climbing mechanism for Round Up and a 3-stage linear lift for the beginning of Gateway. My slides have never bent, even after many hours of running the robot and fierce competition. You must be doing something wrong with them, or are using too much force somewhere.
The only problem I faced with them was friction in my gateway bot.
Guys this thread (and the OP) is talking about the plastic linear bearing blocks that slide inside the rail, not the metal rail. And yes while the rails are heavy, if they made them aluminum, the inside wouldn’t be as smooth and they would be easier to bend.
Lets keep this thread to the blocks, specifically the internal blocks.
The little corners of the delrin bearing blocks work, but I have had them break off. I have also heard of the plastic threads stripping. Using corners like bearing blocks would help, but metal built in thread is stronger. The only thing is, it might be difficult to fit the metal threads in the plastic slide, which is thinner than a rack. Hope vex can do it.
In 6 years I have never had a tab on the delrim bearing flats break off. They work just fine for alignment and theres no reason for them to break off if you tighten your nut and bolt enough so the block does not want to move out of the hole. That would cause them to break.
The delrin slide trucks do not come with threads already on them. It is an undersized 8-32 hole that will self-tap when you screw a 8-32 into it. This is what some teams have an issue with as it does not make mounting the trucks easy.
I highly doubt this will happen. First of all, looking at the CAD if you take the thread insert part file from the rack gear and throw it in an assembly with the current inner slide truck, you can quickly tell that VEX would have to add a decent amount of material to the truck to make it thick enough to house the insert. This would cause new tools to be made for the molds, which would cost them tens of thousands of dollars to do. Additionally, I’m guessing adding at least 2 of those inserts to every truck would probably increase the cost of producing the product (cost of the insert + welding them into the truck) and would decrease the profit margin on the part.
There’s really no need for the insert. It would be easier to make room on the inside face of the truck for an 8-32 nut, open up the holes to 8-32 clearance, and add the square profile tabs, similar to the bearing flats.
However even hollowing out the inside face to allow room for a nut might require a new tool which would probably be no good.