Alternate Source for 1/2" Flanged Hex Bearings

FIRST General Forum
#40

Nobody is suggesting that it’s “part of the challenge.” Jon did point out that there’s a warning in the manual regarding stock shortages, but that’s not the same thing as implying it’s a portion of the desired challenge.

All I see is someone responding to a thread with the general question of stock shortages of a particular part. He replied with how his team works around that challenge. That is a useful and beneficial post, even if it doesn’t immediately solve the overarching issue. A whole bunch of people jumping down that posters’ throat afterwards doesn’t seem particularly helpful to anyone involved

#41

It was definitely a joke, but fair point. I would hope all rookies know who the main FRC suppliers are seeing as they get the KOP drive from AndyMark (which I’ve used multiple years, it’s great), items from VEX & REV, etc.

Sadly, a lot of rookie teams don’t know what they don’t know in my experience - and that’s all over, not just region specific.

FRC rule of thumb should be - buy early, buy at least double of what you think you’ll use if you can afford it. If you don’t use it immediately, you will eventually.

#42

Given the current trade war with China, It might be wise to order your Vex parts early. Also a disruption in one part of the supply chain can effect another part. IE higher demand for US sourced parts. Makes me happy I am not a buyer trying to predict very seaonal demand. Disclaimer: I have nothing to do with Vex, China, or the current administration so my comment is considered speculation. I am not making a political statement, but the political climate does effect international supply chain.

#43

If we really wanted to help rookie teams around the very steep FRC learning curve, the KOP would be able to play the game at a basic level, with the parts in the box.

Never mind, there’s no way a successful STEM program could do that… :rolleyes:

-Mike

Edit: AndyMark’s kitbot is a life-saver. Seriously. 1678 has started not opting-out of the kitbot so we can build one for ourselves each year and be better prepared to help local teams with theirs. Thank you AM!

#44

Back to the thread-necromancer’s question: I don’t recommend it.

About ten years ago (before 1/2" hex bore parts had become an FRC commonplace), I considered using 7/16" hex shafts made from 4140. Rather than just turning down hex stock to fit a round bearing shoulder, I tried broaching a 1406 bearing using this. The results were very bad. I still have that broach. It makes rounded-corner 7/16" hex holes suitable for press-fitting to hex stock, with a large press-in force. I don’t have much need for that normally.

  1. AM is great. Everyone should go buy stuff from them right now.

  2. Re: what a STEM program can do – I don’t expect it to become a cash crop, but Michigan needs to export OCCRA.

#45

I guess I don’t get why anyone would go through modifying the bearing when they could just turn the hex down to round and use a round bearing? Even if you don’t own a lathe you could surely find another team or a sponsor that could turn the ends down.

Fun to read about your pre-hex shaft as a standard trials though Richard. I would not have the patience. People really don’t realize how good we have it now even with items going out of stock. When was the last time anybody used a keyed shaft?

#46

Seriously, anytime a team asks for improvement suggestions the one I always go to is “Use the KOP chassis”. If I look at your robot and see an overweight “custom” chassis that probably took you half the season to build you’re doing it wrong.

#47

Vex is currently out of stock of the 1/2 Thunderhex bearing.

#48

Even though off-topic, this.

If you integrate a kit drive into your build regiment, then you can successfully have a prototype / practice frame ready to go within the first two days of build without having to worry about fabrication at all. Then, you can purchase your competition frame and have that built by the end of week 2. Two weeks to get the majority of your ideas down and ready for fabricating other systems on your robot is so valuable.

Remember, you have an entire robot to design in 6 weeks. If your resources are limited or your mentor / trained student base does not have substantial depth, opt in for the KOP frame or at least a variant.

#49

I can think of two reasons.

First, resources. Teams may have a hex broach but not a lathe - If you are in that situation, the idea of broaching a bearing would certainly appeal over trying to turn down a hex shaft, or even finding someone to do it for you. The thought of a few minutes with a broach and arbor press versus the delay in finding someone to help is appealing.

Second, application/design. I can easily think of several cases on my team’s robot last year where we had the bearing in the middle of the shaft with hex parts on either side. For example, running a WCD drivetrain. You can have hex hubs on your wheels with hex sprockets/pulleys, and the drive rail with the bearing sitting between them. In other situations, we’ve used the VersaPlanetary female adapter this year, supporting the shaft just past the adapter with a bearing to help reduce stress on the adapter and gearbox. That bearing has to be hex, although the other end of the shaft could be turned down and use a round bearing.

#50

I hoped that even the ludicrous idea of a AM support person saying such a thing would make it clear that it was a joke. The reason I chose to use AM over Vex was because I hold AM’s support in quite high regard.

The idea being proposed in the post by a former AM employee was that teams with the resources to stockpile COTS commodity parts deserve the advantage they get as a de facto game challenge created by FIRST and it’s suppliers is absolutely absurd. This is something I think you agree with me on judging by your response to my post.

#51

I mean, there’s also plenty of areas in Michigan that could use their own OCCRA too, not just the rest of the country!

If anyone is looking into starting an offseason league competition like OCCRA, please feel free to contact myself or anyone on 33 and we can work to give you advice and council on things, and I’m sure others involved in OCCRA would be happy to help as well.

#52

I agree. I would like to plant some OCCRA here.

#53

Lol, you guys set up a live webcam of your construction project? :smiley:

#54

Vexpro has them in stock right now for $5 a pop. Why not just order 50 of them if you need them that badly?

We always order at least 50 a few months before the season starts to make sure we have enough for the robots. And generally re-use old ones on the pbot.

#55

I would suggest to scout Alibaba.com for cheap 1/2" flanged hex bearings. I had this idea in mind for a few weeks, but haven’t got a chance to start looking for suppliers and quotes… But if you order products from such websites, you do need to get them through some kind of QA before you use them on a competition robot.

#56

Greetings,
Yep, I nerco’ed the thread. I thought it would be better to keep all the ideas/thoughts/info/opinion in one place. Thank you for the feedback.

**Regarding stockpiling: **We are in the process of doing that now. That’s why I was asking the question weeks before the season started. However, one of the things my team tries to do is have the ability to source items from one than one vendor if at all possible. We believe that flexibility is always important in the supply chain.

Take away: Vex and AM are the only consistent source for these parts according to the experience of those on CD.

#57

I was surprised that this even applied to ThunderHex bearings. My impression had been that Thunderhex used a standard bearing size that you could get elsewhere (but having never needed to use it I never looked). Much to my surprise even the 13.75mm round bearings used with ThunderHex are not a standard part. I think I understand a bit better why some teams still choose to go with 1/2" round keyed stock, it’s far easier to get bearings for them just about anywhere. :frowning:

#58

WCProducts also has them, but experiences the same supply issues as the other vendors. They are currently listed as on backorder.

http://www.wcproducts.net/bearings

That is indeed one of the reasons 1712 stuck with round stock longer than most teams. Back before we could afford to stockpile significant quantities of shaft and bearings, having an immediate quick-turnaround supply from vendors like McMaster was an important consideration for us.

We have since shifted to mostly Thunderhex (with some Hex and Round where applicable) now that we can stockpile before the season.

#59

I think ideally thunderhex size would be a common bearing size, but the profile of 1/2" hex just does not line up to be close to any standard bearing. You would have to round the corners of the hex too much and would not have enough face width for the shaft to be effective.

We made some custom 3/8" “thunderhex” last year that used 10mm bearings and turned down hex. It seemed to work fine, but in the future we will still be stocking up on the vex 3/8" thunderhex and the corresponding bearing anyway, because I would rather have the wider face width.