145 + Glue =awesome? [Archive]

DarkFlame145

29-01-2008, 18:46

Our frame now is tougher then Chuck Norris. All thanks to Mr. Epoxy who is married to Mrs. Rivets.

http://i2.photobucket.com/albums/y25/DarkFlameGTS/FIRST/2008/DSC06839.jpg

http://i2.photobucket.com/albums/y25/DarkFlameGTS/FIRST/2008/DSC06840.jpg

http://i2.photobucket.com/albums/y25/DarkFlameGTS/FIRST/2008/DSC06841.jpg

http://i2.photobucket.com/albums/y25/DarkFlameGTS/FIRST/2008/DSC06842.jpg

http://i2.photobucket.com/albums/y25/DarkFlameGTS/FIRST/2008/DSC06843.jpg

I would like to thank Mr. Wolf and Norwich Glass for doing this for us. Oh and the mentor who to the pics, I'm not sure who it is =P.

Daniel_LaFleur

29-01-2008, 18:50

Looks great ... but it looks awfully low. Do you have enough clearence for the center structure supports?

DarkFlame145

29-01-2008, 18:58

we sure hope so, i have seen bots a lot lower then that.

GrammarNazi

29-01-2008, 18:58

DarkFlame145

29-01-2008, 19:06

Way to not do it yourself... you better hope you dont have to change anything... and thats not really going to make your robot any stronger,it will still flex as much as if it was bolted together, you just wont be able to take it apart now... have fun!

Mr. Wolf is a mentor and Norwich Glass is a sponsor of our team. That is the only thing that was not done out of our shop. Some teams have everything fabbed at a shop then all the team does is put it together.

The weak spots on a frame are it's corners, make them stronger then the frame as a whole will be.

The drive train has been tested, our lift fits on it great, and everything is just right. So there shouldn't be a need to take it a part.

sanddrag

29-01-2008, 19:13

I must be missing something here. Why are you using black goo to join your frame members as opposed to something such as say, bolts? What is that stuff anyhow?

GrammarNazi

29-01-2008, 19:14

GrammarNazi

29-01-2008, 19:20

I must be missing something here. Why are you using black goo to join your frame members as opposed to something such as say, bolts? What is that stuff anyhow?

ummmm welll according to the last 5 or so posts its epoxy (glue)

DarkFlame145

29-01-2008, 19:22

I must be missing something here. Why are you using black goo to join your frame members as opposed to something such as say, bolts? What is that stuff anyhow?

It's epoxy, we are saving a good amount of weight, by not using as many.

Well those teams suck and they should be kicked out, not that they could enforce that... and the corners are not the weakest spot they have 2 to 3 layers of metal unlike the sides which are long and only 1 layer, unless you varied from the default layout a lot.... i sure hope your right when you say it fits cause it would really suck if you had to take it apart...

Bolts can losen during a match and need to be tightened. That makes the frame corners weaker. Epoxy can't losen, so it will make the frame strong all the time. Welding will do the same thing, but welding can make the frame warp. This is just as light weight as welding, but with no warping.

GrammarNazi

29-01-2008, 19:28

if you tighten bolts theyll be fine, depending on how much stress you put on the frame epoxy will crack, it usually shatters like glass only with a lot of stress though, im sure the epoxy will work fine it will just suck ifi you make any mistakes

Madison

29-01-2008, 19:47

Well those teams suck and they should be kicked out, not that they could enforce that... and the corners are not the weakest spot they have 2 to 3 layers of metal unlike the sides which are long and only 1 layer, unless you varied from the default layout a lot.... i sure hope your right when you say it fits cause it would really suck if you had to take it apart...

Welcome to ChiefDelphi. Helpful or inquisitive posts are encouraged here, but whining, complaining or making derogatory remarks about other people or teams is not.

Keep that in mind as you explore the wealth of information that's available here. Not only do other students see what you write, but mentors, sponsors and FIRST personnel as well. Do unto others and all that.

GrammarNazi

29-01-2008, 20:47

i only make remarks at the teams that have there robot fabricated by someone else(that to me is cheating and defeats the whole purpose of this team activity) , i was trying to figure out why this team would use epoxy when bolts are readily available, then when the team said why i explained the epoxy does break and that properly tightened bolts should not come lose. i'm not being mean, i'm being curious and realistic

jgannon

29-01-2008, 21:01

Mr. Wolf is a mentor and Norwich Glass is a sponsor of our team. That is the only thing that was not done out of our shop.
Congratulations on finding a successful fusion of students and engineers that works for your team. It sounds like your team understands the purpose of FIRST far better than teams whose students never touch the robot, or than teams who try to attack this problem with no engineer support at all. Best of luck with the rest of your season.

x7shaddow

29-01-2008, 21:07

lukevanoort

29-01-2008, 21:30

I'm curious as to why you don't get your frame welded, it's stronger then epoxy and bolts togther, you dont have any bolts to lose, and you wouldn't believe how much weight you'd save not using bolts. Becides if you're sure enough of your frame design to epoxy it togther you'd be sure enough to weld it, because grinding off the weldded joints would probabally be a compareable ammount of work to that of removing all that epoxy.
Surprisingly, welding may not be that much stronger than epoxy (if stronger at all). Welding ruins the heat-treatment on the aluminum, which makes its strength take a nosedive. On the other hand, some epoxies are insanely strong and do not affect the heat treatment.

colin340

29-01-2008, 21:46

Surprisingly,welding may not be that much stronger than epoxy (if stronger at all). Welding ruins the heat-treatment on the aluminum, which makes its strength take a nosedive. On the other hand, some epoxies are insanely strong and do not affect the heat treatment.

good point but weld can't shatter they can bend

and GrammarNazi your being mean a your Well those teams suck and they should be kicked out this is mean everyone's being nice to you about this we(I) do not mind this we just want you to under stand first better remember- this is more about gp than robots
-colin

DarkFlame145

29-01-2008, 22:09

Congratulations on finding a successful fusion of students and engineers that works for your team. It sounds like your team understands the purpose of FIRST far better than teams whose students never touch the robot, or than teams who try to attack this problem with no engineer support at all. Best of luck with the rest of your season.

Thank you very much, that means a lot from someone that is from a team that is in an area with a much larger population then little old Norwich, NY

Surprisingly, welding may not be that much stronger than epoxy (if stronger at all). Welding ruins the heat-treatment on the aluminum, which makes its strength take a nosedive. On the other hand, some epoxies are insanely strong and do not affect the heat treatment.

That is very true, when I weld alum. tubing I cause put 2 tubes welded into a "T", let it cool, put it into a vice and rip the alum all around the weld before breaking the weld. It's because the areas around the welds became heat treated and became weaker.

good point but weld can't shatter they can bend

-colin

I haven't seen any of my welds on a robot "shatter", but every year i have one cracked or fully broken weld (often my crappy welds). What is nice about epoxy is that it has some stretch to it.

x7shaddow

29-01-2008, 22:30

Although some very valid anti-weld points have been brought up, out team has had 3 out of our 5 total robot frames (2008 included) with no trouble from welds cracking, or even the aluminum being weakened from the heat, I think we actualy bent our frame last year from so many hard impacts with both the arena, other robots and various shop components (students included :P) and it still has full structural integrity with no strees points showing in metal or welds. I guess one of the main factors would be that they have either been welded with a TIG by students/mentors with more than proficent welding skills or it was sent out to be welded professionally.

bobdahaxor

29-01-2008, 22:31

I'm sorry but it seems like the grammer Nazi needs a lesson on gracious professionalism and needs to represent his team better!

TD78

29-01-2008, 22:40

wow...interesting idea. i'd have never thought of gluing the chassis together. the past few years we have used 1.5" and 2" bolts that go the top and bottom of the end caps and end rails. much much easier than using all those small bolts that come in the kit. this year and last year we've bought aluminum spacers and faced them down so they fit inside the frame rails (otherwise the rails would bend inwards when tightening down the screws). you can see the bolts and the spacers here: http://www.joemenassa.com/images/robotics2008/day19/images/IMG_8368.jpg.

Gdeaver

29-01-2008, 22:59

Metal adheasives CAN be stronger and more cost efffiecint than welding. The mentor that epoxied the frame most likely was trying to expose his team to other joining methods. That is what First Mentors are supposed to do. I try every year to work some composite construction in to our Bot. I posted a picture this week showing another use of epoxy. Hopefully some others saw it and may think of it's use on thier bot.

M4 Sherman

30-01-2008, 01:10

I think you still cant beat a bolt and the next best thing is a weld.

Look at the comparison of Liberty ships built by the U.S. during WWII with rivets verse welds.

And the part about the Aluminum failing around the weld is probable because you're using a thin wall tube (Like 1/16").

David Guzman

30-01-2008, 01:28

This is pretty cool, it is always nice to see teams try new things. Exploring new ways to do things is what makes robots in FIRST better every year. Congrats to your team on trying new things and sharing them with the CD community.

We used the kit frame back in 2005, at first we kept having issues with bolts getting lose. So we reassembled it and used red loctite on all the bolts and nuts, never had a problem after that.

I am a fan of welding most of our stuff, however not all teams have too many welding capabilities and finding another method will help a lot of other teams get rid of those heavy bolts. ;)

sanddrag

30-01-2008, 02:16

Surprisingly, welding may not be that much stronger than epoxy (if stronger at all). Welding ruins the heat-treatment on the aluminum, which makes its strength take a nosedive. According to Metal Forming Magazine, the minimum tensile strength of a weld joint in 6061 aluminum is approximately 24 ksi after welding. The tensile strength of a typical epoxy such as JB weld is approximately 4 ksi. Welding is stronger by a factor of approximately 6 times.

richalex2010

30-01-2008, 02:50

What type of epoxy is that, with what additives (if any)?
Looks like a "normal" epoxy (non-JB Weld) with chopped carbon fibre, or something similar.

A few other additives to think about for anyone using epoxies:
Kevlar
Fibreglass
Microballoons (microscopic glass spheres, looks like powder)
Colloidal Silica (rich man's microballoons, IIRC)

One material I've been trying to get my team to look at is a coupld of layers of fibreglass on each side of a sheet of balsa. Some of the strongest stuff I've used, probably on par or a bit weaker than G-10 sheet, and far lighter.

Composites are great, if used properly. A lot of the time they're overkill, though.

DarkFlame145

30-01-2008, 07:05

I think it's aircraft epoxy, what it's made out of I have no clue. If it is aircraft epoxy then I have 100% faith that it will hold seeing how the stuff holds things that got 300+ mph in the skies.

richalex2010

30-01-2008, 08:48

Yeah, Aeropoxy (and other brands; can't think of them right now) is really awesome. And it actually helps hold together rockets that can break mach three and/or reach FL 300 (30,000 feet) in seconds.

West System and other brands are also really good, and cheaper (not sure about how much cheaper). Polyester isn't so great (pretty much anything you find cheaply), and neither is "hobby" stuff (which is actually more expensive if you need a lot of it; this is anything that you mix with 50:50 proportions).

johnr

30-01-2008, 09:30

we to will be trying rivets and epoxy this year after acouple of years of welding frame. something new. also if it works out,in our case,it would get the whole build back into the students hands. hopefully they won't glue them(hands) together.

jacob07

30-01-2008, 12:11

Since the Kit frame has been available to use, my team has ALWAYS used red lock-tite on the bolts and nuts to hold our frame together, it is a beautiful thing. It works so well!

GrammarNazi

30-01-2008, 18:41

That is the only thing that was not done out of our shop. Some teams have everything fabbed at a shop then all the team does is put it together.

The weak spots on a frame are it's corners, make them stronger then the frame as a whole will be.

The drive train has been tested, our lift fits on it great, and everything is just right. So there shouldn't be a need to take it a part.

So you are saying that the only thing you did was put epoxy in the corners? How is that any better than sending the whole thing to a shop and having everything done somewhere else? A three year old could put epoxy in the corners, seriously...

vivek16

30-01-2008, 19:14

because they still design and put everything together. The reason for this is so that they have more precision parts. i am sure they fabricate things at the last minute but it saves a lot of energy to have it done at a shop.

-Vivek.

DarkFlame145

30-01-2008, 20:14

So you are saying that the only thing you did was put epoxy in the corners? How is that any better than sending the whole thing to a shop and having everything done somewhere else? A three year old could put epoxy in the corners, seriously...

Listen I'm getting a little sick of your crap. We are trying something INNOVATIVE, SOMETHING FIRST IS ALL ABOUT. If you look at the pics, where ever there is a joint on the frame it has been epoxied, not with aircraft epoxy yet. But soon we will be applying the SAME stuff that holds MODERN AIRPLANES together.

The reason why we did it out of shop is because we ran out of time on Sat. and we needed both Sunday and Monday for it to cure. Everything else is made by the students in the Norwich HS tech shop. Except for the motors, wheels (even though in 05 we made our own wheels), and other stuff that comes in the KoP.

because they still design and put everything together. The reason for this is so that they have more precision parts. i am sure they fabricate things at the last minute but it saves a lot of energy to have it done at a shop.

-Vivek.

Yes, everything is designed, fabricated, and tested by our team in our shop.