Surgical Tubing

[Free Willy]

It is possible to buy surgical tubing loops. If it is, where can we buy them. If not, could you recommend ways to make strong loops from the tubing we already have?

Thanks!

[Redo91]

What are you looking to do with loops of surgical tubing?

[laditek]

We have used polycord (metric) in the past and welded it together. To make the best loop. it must be stretched first and then melted together.

[PAR_WIG1350]

Surgical tubing can be tied, if you don't mind knots. Other options are pulling it over metal tubes or rods which are slightly larger than the inside diameter of the tubing, if it needs to pass over pulleys, you could try rubber cord instead of the rods,but I have no experience with that. Zip ties might help.

[Tristan Lall]

Originally Posted by laditek

We have used polycord (metric) in the past and welded it together. To make the best loop. it must be stretched first and then melted together.

A good weld is remarkably strong in polyurethane belting. A 0.375 in V-belt, welded with a hot plate (with a sacrificial metal sheet on top, and a jig to assure alignment) couldn't be separated by two people pulling very hard on it with pliers. (Granted, that's a sizable area under tensile stress, so a lot of force is logically required.)

Originally Posted by Kevin Ray

The best method of connecting ends of surgical tubing that I've seen yet--especially if you want to use it as a loop is to cut about 1.5 in. of pneumatic tubing, then roll back .75 in. of the the surgical tubing onto itself (like folding down socks). Place a few drops of crazy glue on the pneumatic tubing (half of it). Unroll the surgical tubing onto the pneumatic tube. Duplicate the process with the other end of the tubing. The weld will NEVER come apart and is minimally larger than the original diameter of the surgical tubing. We have used that method for many years with no failures yet.

That's a very good idea. Any information on which tubing materials work best for this? (Synthetic vs. natural rubber? Polyurethane vs. other pneumatic tubing?) I've had good success bonding various synthetic rubbers (e.g. neoprene) together with Loctite 409 cyanoacrylate. It's expensive, but works nicely for the purpose.

[Jibsy]

Last year we used zip ties. There was a little bit of slip with only one tie when under high pressure. To remove any slip you could attach the two ends with one zip tie, then fold the overlap back over the zip tie and add a second one there. I can't imagine there would be any slip potential left.

[Kevin Ray]

The best method of connecting ends of surgical tubing that I've seen yet--especially if you want to use it as a loop is to cut about 1.5 in. of pneumatic tubing, then roll back .75 in. of the the surgical tubing onto itself (like folding down socks). Place a few drops of crazy glue on the pneumatic tubing (half of it). Unroll the surgical tubing onto the pneumatic tube. Duplicate the process with the other end of the tubing. The weld will NEVER come apart and is minimally larger than the original diameter of the surgical tubing. We have used that method for many years with no failures yet.
Now, as for the reason why you want to use it.... As mentioned above, use the poly cord it is perfect for this application.

[WillF]

Don't bother with complicated welds and gluings. It's just more effort than it's worth. Knots are just fine. If you are familiar with a water know (usually tied in webbing) it works fine due to the high friction of the tubing. If you don't know how to tie a water knot, look here. Another knot is the fisherman's knot, this works a little better and gives a better angle.

[Kevin Ray]

You're making it sound as though the crazy glue is a bother. You can do the whole thing in a few minutes. The big advantage for Freewilly is that he can use it as a belt and there is no knot which might cause the belt to hop off the pulley.

[NKP13]

Can someone please tell me the rules about surgical tubing, how much we can use, what type and of it we can use, thanks.

[EricH]

Originally Posted by NKP13

Can someone please tell me the rules about surgical tubing, how much we can use, what type and of it we can use, thanks.

I can... but I'm highly reluctant to deprive you of the opportunity to do your own research.

I will tell you that using a Ctrl-F search of Section 4 of the Manual turned up no references to surgical tubing or elastic or springs; it did turn up a few references to tubing, but all of them were pneumatic tubing.

[DonRotolo]

Yeah. We know you can read, and you can access the Internet. Look it up, you'll be the better person for it.

[Molten]

Originally Posted by EricH

I can... but I'm highly reluctant to deprive you of the opportunity to do your own research.

I will tell you that using a Ctrl-F search of Section 4 of the Manual turned up no references to surgical tubing or elastic or springs; it did turn up a few references to tubing, but all of them were pneumatic tubing.

Am I the only one that misses the day when sarcastic reference to reading the manual also came with an answer to the original question?

Originally Posted by DonRotolo

Yeah. We know you can read, and you can access the Internet. Look it up, you'll be the better person for it.

I guess not. Come on, lets be the better person and not pick on the guy/girl. I'm not proposing that we answer every single question posted. I'm not even suggesting that you don't tell them to read the manual. I do suggest that if your going to do so in a condescending tone, you have the courtesy to answer the question to some degree.

Eric, this second part is more targeted towards Don and anyone else that may be tempted to such post.

Don, try not to let a bad day show through to your posts. Hope your next day is better.

Jason

[Tristan Lall]

Originally Posted by Molten

Don, try not to let a bad day show through to your posts. Hope your next day is better.

It didn't seem particularly mean to me.

Incidentally, a relevant issue with the manual is that it's unclear to new users what core concepts are likely to be found inside, and whether a particular thing is an embodiment of one of those concepts. We all know that the typical FRC manual contains references to springs, to pneumatic tubing and to fabricated parts—but it might be non-obvious at first glance whether surgical tubing necessarily belongs to one of those groups. There's no substitute for reading the manual, but a perfect answer would identify the logic behind mentally invoking particular parts of the rulebook (which never once mentions "surgical tubing", the likely search term). That way, the new guy can make the connection for next time.

[Molten]

Originally Posted by Tristan Lall

It didn't seem particularly mean to me.

It wasn't the level of mean that was the issue. It was just the fact that the OP had already been told to read the manual in a quirky manner once. Doing so twice is a bit off-putting. If the "read the manual" statement was followed with something of more substance. I'm not trying to call Don out on this too much. It just seems particularly out of character from him. I'm one that always looks forward to his posts and found this one just a bit disappointing. That's all I have to say about it though as I don't want to single him out any further.

Don, if you have any questions/comments feel free to PM me.

Jason