Is Kevlar Honeycomb allowed?
 

Our team has access to Kevlar Honeycomb, a lightweight board material, and we would like to know if its legal in competition.

Re: Is Kevlar Honeycomb allowed?
 

Hey Bellingham!!

Sure its allowed!! It is a great material...

Most materials are allowed for competition. The costs must be figured out carefully though.

For instance. You must figure out what the smallest piece of honeycomb that could be purchased....if it is sold only in 4X8 sheets you will have to add in the entire cost of the sheet to your bill of materials for your robot.

This costing is kind of difficult the first time you do it but if you read the rules carefully it tells you how to do this.

Remember, even if the material is donated, you must include it in the bill of materials for your robot and you may not exceed $3500 for the robot.

If you have any questions about this let me know...

good luck
We look forward to working with you guys in the Seattle (Tacoma) regional
If you want to come down some weekend and try out your robot please let us know we would love to have you down!!

R

Re: Is Kevlar Honeycomb allowed?
 

also if that 4x8 sheet costs more than $400 then you probably cannot use the material.

Read the rules carefully!

Re: Is Kevlar Honeycomb allowed?
 

...Including the ones about all teams being able to obtain the material.

From the definition of VENDOR in Section 8:
And <R35>:

Re: Is Kevlar Honeycomb allowed?
 

This is not correct. According to rule 8.3.5.1



According to this as long as the amount which is used on the robot has a value less then 400 it is fine to use. I would even say a team would be hard pressed to find a 4x8 sheet of 3/8 aluminum less then $400.

Re: Is Kevlar Honeycomb allowed?
 

If 4x8 is the smallest size the material is sold in, then the entire 4x8 cost must be included in the BoM. You can prorate only when you buy in bulk sizes but smaller sizes are available.

Re: Is Kevlar Honeycomb allowed?
 

That's not how the rule is worded. It doesn't say you account for cost by how much you used. It says you account for cost by the smallest amount commonly available. If you can't get material in smaller than 4x8 sheets, you have to account for the entire sheet in your cost.

Re: Is Kevlar Honeycomb allowed?
 

Hmm, this discussion actually made me realize I’ve been miscounting a cost for 6 years!

Our local metal dealer sells remnants of sheets of aluminum, before now I’ve been just counting the cost I buy those remnants at. I did this because the shop will sell you any amount you want with a cut fee, however since we are a high school they have always waived the cut fee (We usually ask them to cut our 21 foot beams down to 7 foot beams to transport them).

So even though we are buying remnants of aluminum from their cut off shop, we should count the cost of cutting the remnant, even though the person who caused the remnant to be left over paid the cutting cost.

-Jim

Re: Is Kevlar Honeycomb allowed?
 

Jim,
I think you were ok all along.
If the company will do business with anyone, then your costs were just fine.
Anyone would have been able to come in and purchase those materials so they are available to you at that cost. If they would waive the cut price for everyone or for FIRST teams in general , then you would NOT have to add that in either.

It all comes down to being generally available.

Hope you guys are doing welll!!

Robert

Re: Is Kevlar Honeycomb allowed?
 

I am all in favor of FIRST teams using composit materials and construction techniques. We Will be laying up some parts again this year. We will also probable use some pultrustions. However, Some teams have used some of the more exotic composite materials. I contend that many of them are not commonly available to all teams and do not pass the costing guide lines. This was brought up earlier on a prepeg post and now the arimid honey comb. I would love to see a link to a web site or company listing that would sell these materials in small quantities and the pricing. Put some fiber in your robots diet but do it with in the guide lines

Re: Is Kevlar Honeycomb allowed?
 

then there is ebay, where does that fit in. Everyone has an even chance at putting in a bid.

Re: Is Kevlar Honeycomb allowed?
 

Yes, everyone can bid, but only one team can buy each item. I consider ebay to be an acceptable source for COTS items that are also available from an acceptable vendor. I don't know what FIRST thinks of ebay.

Re: Is Kevlar Honeycomb allowed?
 

How much do you need?

If I were able to sell small amounts Nomex honeycomb or Roahcell #71IG foam and other vacuum bagging supplies would that make it legal for the FRC teams that wish to buy it?

Bill

Re: Is Kevlar Honeycomb allowed?
 

Do or can you meet the definition of a VENDOR as described in Section 8?

Re: Is Kevlar Honeycomb allowed?
 

Ok first things first, the rules in section 8.3.5.1 is
The cost of items purchased in bulk or large quantities may be prorated on the basis of the
smallest commonly available unit that satisfies the need for the item.
o Example: A team purchases a 4' x 4' sheet of aluminum, but only uses a piece 10” x 10”
on their ROBOT. The team identifies a source that sells aluminum sheet in 1’ x1’ pieces.
The team may cost their part on the basis of a 1’ x 1’ piece, even though they cut the
piece from a larger bulk purchase. They do not have to account for the entire 4’ x 4’ bulk
purchase item.
So if and only if, the item is available in smaller quantity can you prorate and only based on the smaller quantity price. If you purchased the smallest quantity available then the entire price is listed on the BOM.

Be careful with exotic materials. If they require repairs at competition, and also require special handling during those repairs, you may not be able to make the repairs at competition. Such was the case with composite graphite fiber for ramps last year. If the repairs give off toxic fumes or dust then you cannot expose the public to these dangers and repairs will not be allowed. Even though the material may make it through the approval process using the flow chart at the back of Section 8, the special handling may not.

Re: Is Kevlar Honeycomb allowed?
 

The materials for wet lay up or vacuum injection composite construction are available from many vendors. Amine epoxy resins are available from many vendors. There are many vendors that sell fiberglass, S2, Kevlar and carbon woven and unidirectional dry cloth. All the materials to do vacuum bagging are available from many vendors to any team. I can order small quantities of core materials, raw honeycomb and corrugated core materials. McMaster sells pultrusions along with several other companies. These materials are available to all teams and can fit into the cost constraints. If any team wants to do wet lay up I can list many, many links to vendors that would be happy to help out a FIRST team do composites. However with prepegs and other manufactured composites that are used in aerospace manufacturing, I can contend that these materials are not available to all teams and with order $ and quantity minimums are not available to all teams. Give me a name of a company that I can order some honey comb material and meet the FIRST guide lines and I'll change my mind. Last year our team wanted to use honey comb material for our ramps. I could not find a source that met the requirements so we used polycarbonate and had weight problems. Would have loved to use this stuff. May be I didn't search hard enough. Find some vendors and prove that it's a valid material.

Re: Is Kevlar Honeycomb allowed?
 

that stuff is great we used last year as the platform of our ramp because the wieght to strength ratio was exlent but it costs alot like $500 a sheet

Re: Is Kevlar Honeycomb allowed?
 

I can assure you we spent a lot less than $500.00/sheet. I arranged the purchase about April last year, I have receipts and I pretty sure the cost was closer to $320.00 per sheet.

But it is only 3mm thickness. I think there is a mix of RC model Airplanes, Aerospace and Boat building here, everybody is used to different thickness for their applications. My problem with most vendors is, they rape you on the cost of these materials and/or the lead times are to great to make it a viable option this late in the game.

What I don't understand is why nobody is talking about end grain balsa instead. It's so strong and I would bet it's stronger than Nomex, sure it's a bit heavier, but it's commonly available and this is competition is more about being "Industry Strong" than "Aerospace Lite".

If you want to make some of yourself, I can tell you how to make a precision planer, using a std mill.

Re: Is Kevlar Honeycomb allowed?
 

If it costs that much, you had an illegal ramp. $400, legal; $401+, illegal. (for the smallest available COTS quantity)

Re: Is Kevlar Honeycomb allowed?
 

I'll say it one more time. List some companies I can call today and order some of these materials for my team. Give me the name of a prepeg house that will sell my team a small quantity prepeg that meets the cost reqirements and then we can all go forward and use these wonderful materials. Until then I contend that these more exotic materials are not legal for FIRST use. I went thru the Thomas register last year looking for vendors. I found no company that would be legal by First guide lines. The biggest problems were minimum order quantity, Minimum dollar amount per order or they just do not sell to the general public. I could have gotten some material for our ramps last year from a friends company. I did not because I could not account for it By the rules. May be I should just ignore the GP and take the atitude other teams do. It's OK util some body calls them on it.

Re: Is Kevlar Honeycomb allowed?
 

For small amounts I depend on Aircraft Spruce. Our shop is in Corona, CA. and within a couple miles of their wherehouse, but they ship everywhere and have an Eastcoast wherehouse too.

When I have time to wait for products like S-glass, I use Thayercraft ind. I found them on Ebay and prefer dealing with them, instead of local resources.

Products like Kevlar and Carbon Fiber Tow or Cloth, I prefer to wait for on ebay because most of those vendors are selling Carbon products that have expired their shelf life and are no longer suitable for aerospace manufacturing. Once the expiration date has been reached, it's value drops dramatically. I have no idea how this works out in the rules, but composites that have exceeded their shelf-life, are basicly scrap and are sold as such.

Until the middle of 07', many of the composites were in short supply because of Iraq. Before that time Carbon and Kevlar prices were sky-high, If you could find it at all.

Aircraft Spruce
(my guess is most people already know about Aircraft Spruce)

Aircraft Spruce-Ebay outlet

Thayercraft

I'll post more sites after I visit our shop today.

Also there are work arounds for composite materials, like the end grain Balsa and with good assembly techniques and the use of heat (this time of year is a must) and/or perferated plastic sheets between your Peel-ply and Breather Cloth, you can minimize the amount extra weight gains from the epoxy resins and prevent "Bleed-outs" into the Breather-Cloth that sacrifices strength.

Re: Is Kevlar Honeycomb allowed?
 

Here is a list of companies that sell small amounts of prepreg carbon fiber and other interesting composites. They are not my regular vendors, but they are all well established (20+ yrs) and sources for my personal model airplanes.

Model Research Labs

Dave Brown Products

Bussiness with a greater inventory and higher prices (But are still small amount suppiers)

Aerospace Composite Products

CST-The Composites Store, Inc.

(I think CST will be the most helpful for most FIRST teams)

Another valuable source of information is the "National Free Flight Society", They publish a Symposium every year, many of the authors are aerospace engineers and they have published many articles that can be applied to FIRST

I hope this helps out, I'll post more later

Bill

Re: Is Kevlar Honeycomb allowed?
 

I will add that Robotmarketplace also sells small pieces of Carbon Fiber. Their selection ranges from thin sheets, sandwich foam plates, and structural shapes. A fairly impressive selection, though the prices are to be expected... (I have never purchased CF material from them, so I have no comment as to the quality or availability of this material)

Bengineer

Re: Is Kevlar Honeycomb allowed?
 

These are my normal suppliers for Vacuum bag materials, Composites and Resin & Mold making products. They do not sell in small quantities like Aircraft spruce though.

Richmond Aircraft Products

The West coast supplier for Nomex honeycomb and Roahcell high density foams is Technology Marketing, Inc

For resins and rapid prototype mold materials I use PTM&W There are a few new resins on the market (like MGS), but in my tests none of them showed a strength advantage. The PTM&W products were easier for beginners to work with and were generally better in cold working conditions.

PTM&W also sells a wonderful product called RT2C, to make a very strong mold, very fast at room temp. It is a light weight, 2 part epoxy sand like material. We have also used it like somebody would use Nomex or Roahcell, it has excellent
compression capabilities. Here is it's PDF Data sheet

Hope this helps someone