VexPro Bearings

[kbrowncny]

Our team was planning to use VexPro hex or thunder hex bearings to support a hex shaft in a low load, high RPM application (14k RPM) . Has anyone come across any specs or ratings for hex or thunder hex bearings that they offer?

I know that I can get 1/2" bearings rated to up to 15k or 30k but turning the shaft to a round does not support our application.

In addition, what is the risk to using the VexPro bearings at that RPM?

Thanks!

[Chris is me]

There are no specs publicly available, but teams have used the hex bearings in small wheel shooters in 2013 which spun at similar speeds.

I would suggest ThunderHex so that you don't have any minor issues with runout / concentricity, which aren't always noticeable in a normal hex bearing application but might be at high speed.

[steelerborn]

Honestly the fact that vexpro doesn't have specs online really bugs me.

In the industry we have to consider all of these aspects and bearing selection is a major part of the design.
I don't know what speed vexpro hex bearings are rated for so I can't say exactly if they will work or not. However since they decided to withhold the specs I would assume that the bearing won't work.

I am going to let you in on a bit of info that 5817 learned this season. We changed out the hex bearings on the shooter with bearings from McMaster (who give specs on their bearings) with an appropriate rpm rating, our shooter spun around 1000 rpm faster with just a bearing swap.

I don't know why vexpro doesn't give us this info, I am assuming it is either 1: they don't accurately know, or 2: posting the data will harm their sales.

Let's say that the bearings have a low speed rating this could affect uses in a lot of frc applications besides shooters perhaps even some gearboxes. Vexpro also knows that students might not look into specs and thus never bring up any concern.

[Kevin Sevcik]

Originally Posted by steelerborn

Honestly the fact that vexpro doesn't have specs online really bugs me.

In the industry we have to consider all of these aspects and bearing selection is a major part of the design.
I don't know what speed vexpro hex bearings are rated for so I can't say exactly if they will work or not. However since they decided to withhold the specs I would assume that the bearing won't work.

I am going to let you in on a bit of info that 5817 learned this season. We changed out the hex bearings on the shooter with bearings from McMaster (who give specs on their bearings) with an appropriate rpm rating, our shooter spun around 1000 rpm faster with just a bearing swap.

I don't know why vexpro doesn't give us this info, I am assuming it is either 1: they don't accurately know, or 2: posting the data will harm their sales.

Let's say that the bearings have a low speed rating this could affect uses in a lot of frc applications besides shooters perhaps even some gearboxes. Vexpro also knows that students might not look into specs and thus never bring up any concern.

1. It doesn't look like McMaster sells 1/2" hex bore bearings, or anything close to thunder hex size, so it sounds like you might be comparing apples to pineapples or something.
2. Have you tried asking anyone at Vex for ratings, if they're that important? I suspect the main reason the specs aren't listed is because they're in excess of nearly every FRC application.

[steelerborn]

The McMaster Carr bearings are round bearings not half inch hex, if you lathe down the shafts you can use the round bearings. So I am not comparing apples to pineapples or something.

No I haven't reached out to vex however I still believe they should put the bearing specs on their website. And I don't believe that the bearings specs are in excess for every single frc application. I believe that their max rpm is a lot lower than everyone "assumes". I will reach out to vex about their bearing specs. But 1000 rpm difference with only a bearing swap is very significant in my eyes.

[Jon Stratis]

Originally Posted by steelerborn

The McMaster Carr bearings are round bearings not half inch hex, if you lathe down the shafts you can use the round bearings. So I am not comparing apples to pineapples or something.

No I haven't reached out to vex however I still believe they should put the bearing specs on their website. And I don't believe that the bearings specs are in excess for every single frc application. I believe that their max rpm is a lot lower than everyone "assumes". I will reach out to vex about their bearing specs. But 1000 rpm difference with only a bearing swap is very significant in my eyes.

Did you miss the part where the OP said turning his shaft to round won't work for his application?. That basically means McMaster bearings won't work and he's "stuck" using commercially available hex bearings.

For what it's worth, I've never seen a problem with any of the hex bearings we've used - either custom applications or as provided in some commonly used gearboxes.

If you can contact vex and get a spec for them, you'll know for sure if it'll hold up for your application. If it doesn't, you could try something my team did last night... For one application, we have a hex shaft that we needed to put a specialty bearing (specifically a one way bearing... Those things are so cool!) right in the middle, and a hex bearing just wouldn't work. So instead we got a 3/4 ID version of the bearing, a 3/4 shaft, and bored a 1/2" hex hole in the middle. That lets us put the bearing on the 3/4 shaft, and the 3/4 shaft on the hex shaft wherever we want it, while preserving the hex on either side of the bearing for other applications.

[Greg Needel]

Originally Posted by Jon Stratis

Did you miss the part where the OP said turning his shaft to round won't work for his application?. That basically means McMaster bearings won't work and he's "stuck" using commercially available hex bearings.

Here is an old trick.... get a bearing that fits a 5/8 shaft, get a bushing that is 1/2 ID and 5/8 OD. Broach the bushing, and put it inside of the bearing. Now you have a simple hex bearing.

The one major issue with this is that I have not found a 5/8 shaft bearing with a 1.125 OD, but if that doesn't matter to you this is a good stand in solution, that many teams used to used before hex bearings were common.




On a side note, I also have been meaning to ask what the specs of the hex bearings are, both in RPM, load, and rated life. We have some that during prototyping (spinning at only moderate speeds) seemed to get really loose quickly, I assumed it was either an old bearing or we were beyond the spec. We changed the design, but it would be good to know for the future.

[Kevin Sevcik]

Originally Posted by steelerborn

The McMaster Carr bearings are round bearings not half inch hex, if you lathe down the shafts you can use the round bearings. So I am not comparing apples to pineapples or something.

No I haven't reached out to vex however I still believe they should put the bearing specs on their website. And I don't believe that the bearings specs are in excess for every single frc application. I believe that their max rpm is a lot lower than everyone "assumes". I will reach out to vex about their bearing specs. But 1000 rpm difference with only a bearing swap is very significant in my eyes.

Sorry, were you using half inch round Vex bearings and then switched to half-inch round McMaster bearings? If so, then I'll agree that the McMaster bearings were an improvement over the Vex.

If you're talking about switching from half-inch HEX bearings to half-inch ROUND bearings, then that's a whole different ballgame. Vex notes in a few places that hex shaft in hex bearings can have some tolerance issues, and I would expect them to have some minor issues running at higher speeds. So apples to pineapples.

[PowerfulKitty]

We used Vex 1/2" hex bearings for a prototype shooter that ran with 775 pro motors at full speed with no issues.

[TylerS]

Early on in the design process I tried looking up the specs for both Vex Pro and Andymark's 0.5" hex and round bearings to no avail. Still we are using them anyways in our shooter simply because there's not a good alternative.

It would be interesting to get a spec sheet and some data from practical testing through typical FRC uses (shooters, drive trains, high load applications, etc) so teams can make better informed design decisions.

[steelerborn]

I read the op I was just posting what we were able to do.

Vex emailed me back with no info, but they said they would be contacting soon in this thread.

I am just so surprised at these reactions, all I was saying is that bearing specs should be posted and how going from 1/2 hex to the McMaster high speed round bearing made a difference.

[Kevin Sevcik]

Originally Posted by steelerborn

I read the op I was just posting what we were able to do.

Vex emailed me back with no info, but they said they would be contacting soon in this thread.

I am just so surprised at these reactions, all I was saying is that bearing specs should be posted and how going from 1/2 hex to the McMaster high speed round bearing made a difference.

To be fair, you did accuse Vex of withholding damaging information from customers to bolster sales of their product. Which is is kind of a serious accusation.

[Ryan Dognaux]

Originally Posted by Kevin Sevcik

To be fair, you did accuse Vex of withholding damaging information from customers to bolster sales of their product. Which is is kind of a serious accusation.

ding ding ding we have a winner... Basically steelerborn, you come off as a jerk. I'm sure you didn't intend for that but there it is. Not posting product data because it will harm their sales... mkay.

[steelerborn]

I said that it was only one possibility, let's say that the half inch hex bearings are rated for only 1000 rpm, I would imagine that would affect their sales. I like vexpro I think they are doing a great job.

However I don't think it is too much to ask a supplier to post the load specs for their hardware. Especially when in the workforce students will one day have to understand bearing selection and the reasons why.

I can't be the only one who thinks they should put those specs online.