[FTC]: Custom Materials
 

In the game manual, Rule <R5> c 18 says all mechanical fasteners (nut, bolt, screw, etc.) of any length, any thread type, up to 3/8 in. diameters are allowed.

However, it also says the intend of the rule was to allow teams to use fasteners similar to TETRIX ones from local stores.

Currently my team is not registered so we can't post questions on the forum but can someone post the following questions on the official FTC forum?

1. Sheet metal screws, hex bolts, lock washers are not in the TETRIX kit but the rule <R5> c 18 says ANY mechanical fasteners are allowed, so are they legal for FTC?

2. Are 6-32 thread lock-nuts allowed?

3. Are 6-32 thread socket head cap screws longer than the ones in the TETRIX kit allowed? Longer as in 2 in, 3 in, etc.

4. Our team bought 1/16 in. aluminum square tubes from a local store and the decimal equivalent of 1/16 in. is 0.0625 in. However, on the receipt it round the decimal places up and it's written as 0.063 in, which exceeds the thickness limit. Would the receipt be a valid proof of thickness since it's a systematic issue, not the actual thickness?

Thanks in advance. My team and I would certainly appreciate it if anyone post these questions on the forum for us.

Also, what do YOU / YOUR TEAM think about the new rules lifting maximum constraints on custom materials?

Re: [FTC]: Custom Materials
 

18. All mechanical fasteners (nuts,bolts,screws,etc.) of any length, any thread type, up to 0.375” (0.9525cm) diameter. The intent of this rule is to allow teams to use fasteners from any supplier that are substantially the same as TETRIX fasteners. Compatible fasteners are characterized by using the same thread characteristics as TETRIX fasteners. For example, an acceptable substitute for the TETRIX 6-32 thread,1/2" length socket head cap screw is a 6‐32 thread, 3/4" length, button head cap screw purchased at a local hardware store.
Emphasis mine.

I do not remember any sheet metal screws in the Tetrix kit.

The receipt should be acceptable proof, if needed. Most often a comparison with other Tetrix parts on the robot is sufficient to determine thickness.

Re: [FTC]: Custom Materials
 

The intent of the rule was what I had confusions about.

In last year's game manual, it allowed Compatible mechanical fasteners of any length.

If the intent of the GDC was to let teams use the screws they buy from a local store, last year's rule allowed teams to do so already.

I was just wondering if this allows us to use other kinds of fasteners even though it's not the intent of the rule. Because like I said up top, if the point is to allow teams to use screws bought from a local store, there's no point changing last year's rule.

Appreciate your help!

Thanks

Re: [FTC]: Custom Materials
 

Henry,
The language in this rule is essentially the same as last year except for the allowance of the 3/8" fastener to allow for the threaded rod. As always, the Q&A has the last word on this rule. I am having an issue logging onto the FTC website.

Re: [FTC]: Custom Materials
 

The GDC most likely change the rule to compliment the allowance of the threaded rod.

That makes sense now.

And like you said, the official Q & A have the final say.

Thank you!

Re: [FTC]: Custom Materials
 

Does anyone know if we're allowed to use springs? I've seen other teams in the past use them, but I don't see anything specific listed in the game manual. Thanks.

Re: [FTC]: Custom Materials
 

Tom,
Springs are allowed if they are Tetrix or Lego parts. Rubber bands are also allowed.
R5-C
21. Any number of Rubber bands size #32 or smaller, (i.e.0.125”/0.3175cm thick & 3"/7.62 cm in circumference).

Teams may use any of the allowed materials as well.