? bending delrin

[prusik333]

I am trying to bend 5/16 delrin for my Bully
will this be ok, that notch on top of the link?
i would hate to do all 4 lower links and they break at that notch
i tried 4 other links and they are not getting any better

I'm using a Master Heat Gun 300' to 500' / 12amp 60hz
thanks

[NeXt559]

it looks like you only heated one side. and yes they will break at that notch. check out some pics of bent delrin links notice the bend tends to be pretty wide

[cwneuwirth]

WOW, how are you bending those. I think you need lower heat for a longer period of time to heat up the center on the link more. I made bent links for my super out of 1/2" delrin. I heated them up slow on low heat, then bent them half way, let them cool. Them heated them up again for the last little bit of bend. That way you don't stress the delrin too much. I would use those as a learning experience, and try again. The last thing you want is for them to snap on you during a comp

[prusik333]

thanks, I only did heat the one side, i figured i would just heat it up until i can bend it oops
i'll try it again, thanks

[prusik333]

Originally Posted by cwneuwirth

WOW, how are you bending those. I think you need lower heat for a longer period of time to heat up the center on the link more. I made bent links for my super out of 1/2" delrin. I heated them up slow on low heat, then bent them half way, let them cool. Them heated them up again for the last little bit of bend. That way you don't stress the delrin too much. I would use those as a learning experience, and try again. The last thing you want is for them to snap on you during a comp

I just drilled a hole in my crapy wood desk, heated it up with a heat gun for about 2 minutes, put the end in the hole (drilled to 30mm) then bent it, it bent pretty easy.
i will put it on a lower setting and heat it up slower
thanks guys

[Ripperfi]

Easiest way to bend delrin rod below 1/2 is with a big block of wood. Drill a hole about 1.5 - 2.5 inches deep the same diameter as the rod you are bending. Mark on one where you want the bend then wrap a piece of electrical tape around the rod on both pieces so as to match up when inserting into the block. Insert the short end into the hole then use your brute strength to bend the rod down to the block of wood. Release, then do it again 2 or 3 more times. Do the other piece the same way and when your done you will have perfect 30ish degree bends. As an added step you can place both pieces in boiling water for about 15 minutes then plunge into ice water. This process I was told finalizes the delrin's molecules and makes it stiffer. If you want your ends tapered, simply chuck them up in a drill and grind away on a file at an angle. After a few tries you'll get the hang of it and be able to get the ends matching and even. Then bend them, boil them and your done.

EDIT: Its unnecessary to heat the rod prior to bending if its under 1/2in.

[prusik333]

Originally Posted by Ripperfi

Easiest way to bend delrin rod below 1/2 is with a big block of wood. Drill a hole about 1.5 - 2.5 inches deep the same diameter as the rod you are bending. Mark on one where you want the bend then wrap a piece of electrical tape around the rod on both pieces so as to match up when inserting into the block. Insert the short end into the hole then use your brute strength to bend the rod down to the block of wood. Release, then do it again 2 or 3 more times. Do the other piece the same way and when your done you will have perfect 30ish degree bends. As an added step you can place both pieces in boiling water for about 15 minutes then plunge into ice water. This process I was told finalizes the delrin's molecules and makes it stiffer. If you want your ends tapered, simply chuck them up in a drill and grind away on a file at an angle. After a few tries you'll get the hang of it and be able to get the ends matching and even. Then bend them, boil them and your done.

I'm i understanding this right?
so your bending the delrin 90' to the wood without heat, 3 times and it will stay at that 30'
i just want to get this right, before i run out of delrin
i know hire the handicapped

got it, thanks
EDIT: Its unnecessary to heat the rod prior to bending if its under 1/2in.

[Ripperfi]

You got it Be sure to drill and tap, then taper, bend, boil, done.

[prusik333]

Originally Posted by Ripperfi

You got it Be sure to drill and tap, then taper, bend, boil, done.

thanks Ripperfi
i tried some 3/8 stuff i had laying around
bent it 3 times and it worked stayed at that 30'
bent it 2 more times after that to show off to my buddy and it snapped in half. it's 27' outside and only 46' in my work shed, so i'm sure thats why it broke. I will keep the delrin inside tonight and bend it Monday.....after i drill, tap & taper
thanks for all that responded, another tip learned

[Reflection]

Weather heats needed or not,it does make it easier. You don't need much at all. The 5/16" delrin I've bent,I just held a cigarette lighter under it for a few seconds and it bent SUPER easy

[prusik333]

thanks Reflection
can't wait to try them out on my Bully, my alum. links are bending all over the place. i know the 5/16 Delrin with Revo rod ends will work alot better, had them on my DNA comper and they held up great

[xirtic]

I use a heat gun for 10 seconds on the bend location (Until the Delrin looks a little glossy). I also use 1/4" Delrin Tube over 4mm threaded rod stock. This is very rigid, and does not flex. IT also gives a little more clearance around the gear box.