$0.73 per Flanged Bearings 1/2'' HEX and 13.75 mm Thunderhex


Hey FRC Teams,

I am Kenneth from FRC 5857! Recently, there has been a shortage of bearings and our team desperately needed some. Therefore, we have been in contact with a Bearing Factory in China who is able to make the 1/2 inch Flanged Hex Bearing (comptable with Hex shaft) and the Flanged Thunderhex (13.5mm) Bearing (compatible with Thunderhex shaft). Using the same measurements from other platforms (Flanged Bearing- 0.500" Hex ID x 1.125" OD x 0.313" WD and Thunderhex 13.75mm (1/2" ThunderHex ID) x 1.125" OD x 0.313" WD) being the model FR8ZZ (general bearing model # that FRC teams use).

$0.73 + Shipping Cost to USA + Shipping from LA to wherever you are.

Quality: The manufacturer said their bearings are typically used for Go-Carts and Electric Motorcycles along with different machinery. And the materials will come from Japan for better quality.

Arrival time frame: We have told the factory and the shipping company that we WILL NEED the bearings in the US by January 5th, 2018. They have verbally agreed. Since I am visiting China for Winter Break, I will be stopping by at the Factory to ensure the deadline can be made.

FRC Team 5857 and I WILL NOT profit from this sale. We have only started to look towards a different alternative to the current platforms for bearings. We see this as a great opportunity for teams to get cheap bearings. Since our minimum order is 5000 bearings, we would like to offer this amazing deal to all FRC Teams.

Noting: This is our first time ordering from this supplier, we have spoken with them on the phone over five times yesterday, and a few times today. Throughout the week, we have also been continuously texting each other. In my opinion, it seems like the manufacturer is trustable and can have bearings sent to the US by Jan 5th, 2019 and maintain a high quality. However, if you purchase these bearings. Please remember that we are trying our best to meet the kickoff date and produce bearings with good quality. :slight_smile: :slight_smile: :slight_smile:

**We would like to have 2500 bearings “pre-ordered” or have interested, before confirming the order. We are at 1200ish right now. Please order ASAP. **

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Chinese Bevel Gear Group-Buy -- Gauging Interest!

Have you spoken to vex to find out if it’s OK to use their product design and name?

This forum is sponsored by vex, and I have a feeling they might not like you undercutting their pricing and using their product name.


Can you describe your plans for receiving, repacking, and shipping these bearings once they arrive in LA? Can you tell us how long you’ve scheduled for customs processing?

Extraordinary claims require extraordinary evidence.


And further, I’d want to know the seller of record so I could document the VENDOR (as defined in recent game manuals).

They could probably be more thorough about their phrasing and use of Vex’s proper product names*, but I also think it’s possible to have compatible bearings without concerns about product design here.

*I run programs that use LEGO® Bricks. Part of the training was a good couple hours on their Fair Play guidelines, and what we can and can not say in our messaging that uses their trademarks. It can be a tightrope.


How are you going to QA the bearings?

How are you sure they are not going to get caught in customs?

Have you figured out the import fees on the bearings.

How do you know that these guys are just not going to go and find the vex supplier and try to buy it from them and re-sell it to you? (Common).

Just be careful that you are not getting scammed (also common).


A quick patent search revealed nothing, a 13.75 MM ID bearing is not new technology. However, I do agree that using the “ThunderHex” name in this thread and the survey is very poor form.


Yeah, “ThunderHex Compatible” or “ThunderHex size” would probably be better to use.

OP, despite the possible trademark issue, I hope your venture is successful so teams can get the parts they need. I don’t think my team will be involved right now, but don’t let this discourage you from sharing this with more teams and doing this in the future.


Funny how some memories stick in the mind for a long time.

More than fifty years ago, I clearly remember seeing this quote attributed to the 19th century polymath John Ruskin, posted high on the wall of a Baskin-Robbins* ice cream shop in Decatur, Georgia:

“There is scarcely anything in the world that some man cannot make a little worse, and sell a little more cheaply. The person who buys on price alone is this man’s lawful prey.”***

*As an eight year old, I mistook Ruskin for Baskin, and thought the quote must have come from the owner of the ice cream shop. I learned who Ruskin was many years later, but the memory of seeing that quote has stuck.


My family does a lot of importation of items from China to USA. From past experience, it takes 5 days for the times to leave China. Upon arrival to LA, it will take ONE day for items to get processed and for customs to release it. We have a company that handles all this for us, sometimes the items are even processed before arriving in LA. Typically, customs will charge 10% for import tax. However, the recent “Trade War” (don’t want to involve politics in anything) has increased some items to 25% for import tax.


I have just edited the form and the post. Thanks for letting me know.

My intentions were not to create competition with Andymark or Vex or WCP. There have been a lot of teams in my area that urgently need bearings. Therefore, I started to look for some suppliers.

I am just trying to help a few teams along with the teams that I mentor. Having a 5000 minimum. I wanted to offer this to more teams.



A few years back, gen1 hex broach gears were often noticably not concentric. Is the supplier experienced with holding a concentric tolerance on those parts?

The nominal size of the thunderhex bearing is 13.75mm, but a few tenthousandths is enough to take it from “slip fit” to “press fit” tolerance on the hex stock. Do you have the dimensions defined well enough to ensure the desired fit? (We have ~100 pressfit bearings that I find hard to use)

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inb4 they’re anodized red


Look man, whatever your intentions are, you’re effectively entering the market with this. Personally, I put in for a few-- here’s hoping you’re successful, even if I expect some kinks the first time around.


I saw your post on Facebook and was going to write there, then I saw this. I don’t think this is a great idea. You said you need bearings? I don’t mind going communist sometimes. We just inventoried and we have about 100 hex bearings, and about 80 Thunderhex bearings that were slightly undersized and require you to sand off the corners of the hex. Want some? I bet other teams have extras too and can spare some


So… While everyone else has technical and supply side questions, I just wanted to say hi from your team number neighbor. Good luck with this, I know a lot of teams are hurting for these right now.


Producing these at cost and sharing the opportunity to get some with other teams is commendable. However, there are some definite ethical hurdles you need to be aware of when going into business.

It would be very easy to contact vex and ask them how they would like this handled. Barring that you could just remove any reference to thunderhex and call out the appropriate dimensions or describe the important features in depth. Even when there is no legal barrier like trademarks, there is an appropriate way to do this.

I wish you the best of luck.


We’re a small team with a small budget, but we’re interested.


I put down interest, although I do have reservations.

First is legality. Are the bearings standard parts from their catalog, or is this a custom order? It sounds to me like you aren’t ordering a part number, but rather providing them with specs so they can create a custom order. That would mean it’s not COTS, and is thus subject to the rules around manufacturing dates - it would have to be produced after kickoff in order to be used on a competition robot (again, per the 2018 rules). They could still be used for off-season stuff, practice robots, etc. And at a potentially cheap price would be worth stocking up for that use. But there is definitely some clarification needed before you potentially get other teams (and yourself, of course) in trouble with inspection.

Second is quality control. “Materials will come from japan for better quality” doesn’t really mean anything. What materials, exactly? Has this company gotten you a sample of the finished bearing so you can do your own QA on it, ensure concentricity, load tolerance, and everything else vendors like Vex and AndyMark do on their parts? I could see a company unfamiliar with hex bearings very easily designing and building a bearing, and then broaching it, and leaving the walls to thin at the corners, making it subject to breakage under stress.

Third is the unknown cost. Advertising it as 73 cents per bearing is extremely misleading. You state you haven’t taken into account shipping costs yet… why not? What about export costs? What about customs cost? With Vex’s new 12-pack, bearings are down under $5 each - are you completely, 100% sure your solution is going to be cheaper than that?

I understand the urge to look elsewhere when you see out of stock notices on items, and it’s great that you’ve gone as far as you have so far… but there’s still a lot more work to be done before I would feel comfortable placing an order.

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My advice would be before approaching anyone about potentially buying from you or working with you, make sure you figure out all the fine details. You will often find that there is an unknown financial factor that screws up plans like this (shipping, taxes). Getting parts like this is always way easier when you are a very large company and tends to only become more expensive the smaller you want your operation to be. Myself and another 865 student actually tried to run the numbers on doing a similar thing for box tube (Aluminium stock, extrusion, transportation, etc.) and we found that we would actually need to sell about 28000 pieces of box tube to make it work. Just want to make sure that you have everything ready before getting other teams excited. Having said, if you can make it work withing FRC rules, all the more power to you.


If you think a $0.73 bearing is going to cost $5 after taxes and shipping, you need to order more stuff online. I’m betting this will hit about $1/bearing after taxes, maybe $1.50-2.00 after shipping. There is a world of difference between buying bulky and heavy aluminum tubes and comparatively tiny bearings from China.
The 13.75mm sounds fine to me, but the hex will probably suffer from the thin corners if the factory is using a standard R8 as the base for it. I’ve asked 1072 if we can buy 50 or so of the 13.75mm bearings.