Gluing Robot Frames

To branch off from Rion’s thread here is a thread to discuss gluing frames which was initially brought up by IndySam as an alternative to welding the frame

Quotes from Rion’s thread are the following.

I would like to see Pics of this in action too.

This is a very intriguing idea, never seen this before. But, I have a question about it…

In an emergency situation, how do you take these glued joints apart? If its welded conventionally, you just take out the grinder and its done. The epoxy seems a little more permanent seeing as they’re saying the aluminum fails before the epoxy.

For this reason, 810 has never welded anything due to the fear of having to change out a damaged frame piece or make a last minute design change, which has happaned to us before.

I have to ask the question as to how do you make repairs at competition sites?

We have a meeting Monday afternoon and I will get some pictures and more details.

If you need to take a joint apart all you need is a good application of heat. We have done that with axles glued into support blocks.

As far as repairs go, we haven’t had a frame failure in five years. We like to build our robot so we spend our time fixing other peoples machines instead of our own.

The standard repairs would apply. A good hacksaw or a trip to the welder for some heat application to separate the joint. Then either a welded repair or bolted repair. If there is a evening to allow the epoxy to set then re-gluing will work.

We glued and stapled our chassis together last year. But it was made of plywood, not aluminum :slight_smile:

In the case of wood, you can use superglue to repair it relatively quickly. I don’t know how effective that would be with metal, though.

http://i18.photobucket.com/albums/b109/scott4020/frame-1.jpg

This is the building sketch from last years lower frame. The connector pieces were simplified because our machining capabilities were more limited last year. This year we have the machine shop teacher as one of our sponsors and his best students are lined up and excited about making parts for us so we can make connectors more like the quick frame pieces (wow that’s a long sentence.)

You can see how we notched some of the pieces (kind of like Lincoln Logs) for assembly. We had more of these on the upper frame than the lower frame. These were hand fit and very strong when glued.

The holes you see are for 1/2" aluminum rod that connected the upper and lower frames together. Pictures I will take Monday will show this better. This may also change with our new machining capabilities.

IndySam, which Hysol product are you using?

It was the E series two part epoxy in the tubes. I don’t remember if it was the CL or HP. I will have to check in the shop to make sure and get the exact part number.

I just started a thread on Connecting Quickframe because I didn’t want to hijack this one on gluing. I would be interested in more detail/photos of how you notched those pieces that fit together like Lincoln Logs. Are those oversized pieces of aluminum or still Quickframe? If the later do you just bend the flaps out to go around the other member?

http://i18.photobucket.com/albums/b109/scott4020/Mobile%20Uploads/0104001407.jpg

http://i18.photobucket.com/albums/b109/scott4020/Mobile%20Uploads/0104001406.jpg

These first two picture show the types of connections we used last year. You can also see where we later riveted in some 1/16 wall tube to support the electronics board.

http://i18.photobucket.com/albums/b109/scott4020/Mobile%20Uploads/0104001454.jpg

This shows how we did the “Lincoln Log” type connections.

Last year we used E-20HP and E-60HP (the difference is working time.)
This year we recieved a case of E-30UT as a donation. This pick is a test of this product. Notice that the tube gave way and the epoxy never did.

http://i18.photobucket.com/albums/b109/scott4020/Mobile%20Uploads/0104001428.jpg

Kind of bizarre to see.

I guess you guys do CADD before doing any gluing?

-Tanner

Draw yes, CAD no. Not last year at least.

0117091538.jpg

This is what the product looks like that we used last year.

0117091538.jpg


0117091538.jpg

Our team uses machine screws and the normal Quickframe nylon connectors to secure the pieces together. For high stress applications, we sometimes drill a through hole and use a 10-32 bolt.

My question is, what is the advantage to the notched “Lincoln Log” system as opposed to adding another T joint? The Lincoln log system wouldn’t work so well with standard Quickframe because of the rounded edges.

In the picture, it looks like the used standard 1/8" wall tubing. I question doing this with 1/16" wall quick frame.

We always use 1/8 wall tube for the drive part of our frames.

You would have to ask someone who uses Quickframe about how it might work.

So, we know that 1/16 wall quickframe is pretty close to 1/2 the weight of the T10 extrusion, but what about 1/8 wall tube?

From what I understand Quickframe weighs very similar to a standard square tube so 1/8" wall tube likely weighs about twice what 1/16" wall Quickframe does.

1010 is .5097lb per foot, 1/8 wall is .5132lb per foot, 1/16 is 0.2729, Quickframe should be similar.

We only use 1/8 wall for the drive portion of our frame. These parts are subject to maximum abuse and are difficult to repair. They also seem to get the most holes drilled into them to attach other things so the extra thickness of the wall is an advantage.