3D printing elevator bearing parts

The team I’m mentoring this season is looking at building a horizontal slider type deal similar to WCP Competitive Concept and we initially thought that we could repurpose the AndyMark Climber in a Box to do that, but upon further inspection, the Climber in a Box uses nylon sliders and we think it will cause binding when a load is placed on the end.

We also don’t have much of a budget to buy more Thrifty-bot bearings, so I was thinking about 3d printing brackets and buying bearings from McMaster-Carr, however I’m not sure about the print strength. I’m thinking as long as we print with PETG and print off-axis with a higher infill, it will be fine, but I’m not sure as I have not personally printed with PETG before, nor do I know what kind of forces an elevator bracket experiences.

I’m hoping someone here can provide some insight, thanks!

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I did this in 2018 and we popped our entire elevator out of its frame in our first match.

Not saying you shouldn’t do it, but you need to be really careful. Some have done it successfully, others have had trouble. I would be extremely cautious.

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Little did we know how apt the #hellavator slogan would be

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This is definitely one of my fears, we don’t meet that often, so I don’t know how much testing any custom part would get outside of me doing it at home without the students, and I would rather the students have a hand in testing a custom part.

If you’re looking for a more budget-friendly version of the CC, there’s a simpler version that goes on a kitbot and uses fewer components. It was released alongside the CC, but the render wasn’t finished yet so it wasn’t in the promotional material. I believe the cad model is on the website under the 2023 CC zip file. In the meantime, you can get an idea of what it looks like here: https://drive.google.com/file/d/1WdOqdsVR1pl41DJrwQBEg_8Y6sYsucA_/view?usp=drivesdk

Now this being said, the CC (and the simple CC) still aren’t the cheapest options out there. If money is a primary limiting factor for your team, and the CC is close to the edge of your budget range, I would not recommend blowing the budget for a CC 2023-esque robot. Instead, consider alternatives that will keep you within your price range and keep your team afloat. If you need help finding options like this, feel free to send me a message and I can work with you on making some of your designs cheaper without sacrificing reliability.

I think you’ll find McMaster prices on most bearings are pretty high.

If you really need cheap cheap bearings, look around on Amazon. Deals to be had, very thrifty.

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EDIT: oh yeah this is similar to above

When I did a build-buy analysis of several elevator bearing blocks, I did a similar thing: I looked up same spec bearings on McMaster and compared the price to the blocks.

Even with the cheapest bearings (single, not packs, though…) the ThrifyBot came out to be something like $1 more than the bearings, which seemed ridiculous. (As in $1 per each block bought you the 1/4" Aluminum and the bolts.)

I was wondering if you’ve done something similar to check my sanity.

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Our plan was to mimic the cc, and custom make the specifics. We aren’t locked into any specific horizontal mechanism yet, so we still have the option to switch to a cheaper mechanism if we absolutely need. I’m working on a CAD mock-up right now so I might do some mock-ups of other options for the students if we can’t find an adequate solution to this.

I haven’t quite looked at bearing prices closely, as this problem only came to my attention in the past 3 hours, the bearing prices costing as much as the COTS kit would definitely affect our decision. We have a lot of tubes of bearings laying around, I’ll have to check at our meeting tomorrow to see what we have on hand. Absolute worst case scenario, I can steal the bearings out of my skateboards or dig up my old bearings from one of my project boxes at home. small interior bearings are definitely gonna be the tricky part.

We were also talking about other mechanisms, so we might have to ditch this one if it won’t work out.

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If you’re looking to mimic the CC and bearing blocks price points are a difficulty, send me a DM with how many you need. I’ve got extra WCP credit my team doesn’t need, we’ll see what we can do about getting you the blocks. Elevators are hard enough as it is, and messing up bearing blocks can ruin a season.

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Do you need bearings or bearing blocks to mount the bearings?

Our climber last year was similar to the thrifty climber/Andy mark climber in a box and used 3d printed blocks to hold the bearings.

may be somewhat off topic but has anyone attempted to 3d print spools for wire driven elevators? My assumption is that there would be problems with the cable cutting in to the plastic but i have limited experience dealing with it in practice.

we’ve found some bearings laying around, so now we’re looking for advice on printing. I’ve personally never worked with PETG, but from what I understand it’s pretty strong and can be printed on some of the hobby grade printers that Michigan Tech has for students.

I believe 857 did that in 2018, you would have to double check with @Christopher149 as my memory of those specifics is a little hazy.

I don’t think it was wire either, I think it was polycord from andymark.

Are you trying to do a tube in tube style or an elevator style?

We have done this. We have had both success and failure at it. On lighter load elevators, it worked alright. On a climber it split out pulley in to pieces.

elevator style, we currently have a lot of 2x1 tubing on hand, so I was thinking to use that if possible.

If you are 3d printing them, My best advice is use a lot of material. Make the parts much thicker than you need. You can also do some tricks to use the bolts through the bearings to your advantage.

PETG is pretty good, we do a lot of spacers and other things like that out of it. We have access to a markforged so we use that in high load places.

What team are you with now?

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I’m working with 5486 Robotic Turmoil out of Lake Linden, MI right now. Their lead mentor is fairly new to FIRST and I think the most experienced student has only been on the team for two years. There’s a crew of about 5 of us college students lending them as much experience as we can, lol.

They’re goal this year was to not just do an every-bot, and to get picked for elims at their district events, so, assuming we can get this design to work, I think they’ll have succeeded in their goal.

What size bearings do you have on hand?