# Bi metal CAD designing **URL:** \ **Category:** General Yo-Yo\ **Created:** [April 10, 2016, 2:46pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018 "2016-04-10T14:46:30Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![yoyoguy2017](https://avatars.discourse-cdn.com/v4/letter/y/45deac/32.png) [@yoyoguy2017](https://forums.yoyoexpert.com/u/yoyoguy2017)\ **Post date:** [April 10, 2016, 2:46pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/1 "2016-04-10T14:46:30Z")
Hey, I design yoyos for an upcoming company, and I’m not sure how to design bimetal throws. I don’t know whether to make the rings separately, or cut of part of the cross section and make it a ring, I don’t know. Do I make it so the snaps together with the rest of the yoyo? ---
**Author:** ![sparhawk](https://avatars.discourse-cdn.com/v4/letter/s/94ad74/32.png) [@sparhawk](https://forums.yoyoexpert.com/u/sparhawk)\ **Post date:** [April 10, 2016, 4:16pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/2 "2016-04-10T16:16:58Z")
Generally the rings are made separately and then thermally fitted to the other part of the yoyo. ---
**Author:** ![wishiwasayoyoexpert](https://avatars.discourse-cdn.com/v4/letter/w/a88e57/32.png) [@wishiwasayoyoexpert](https://forums.yoyoexpert.com/u/wishiwasayoyoexpert)\ **Post date:** [April 10, 2016, 4:34pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/3 "2016-04-10T16:34:46Z")
A guy posted a picture of a bimetal cad in the facebook yoyo designers group a few days ago. He just attached it to the rim of the yoyo on the design, and I assume just assigned the material separately from the body of the yoyo. They’ll need to machine the two parts separately for obvious reasons, but you can attach it to the yoyo body on the actual cad so you can have an idea of how it would actually look. ---
**Author:** ![yoyoguy2017](https://avatars.discourse-cdn.com/v4/letter/y/45deac/32.png) [@yoyoguy2017](https://forums.yoyoexpert.com/u/yoyoguy2017)\ **Post date:** [April 10, 2016, 4:37pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/4 "2016-04-10T16:37:47Z")
> [@sparhawk](#): > > Generally the rings are made separately and then thermally fitted to the other part of the yoyo. by thermally fitted, do you mean welded onto the yoyo? ---
**Author:** ![wishiwasayoyoexpert](https://avatars.discourse-cdn.com/v4/letter/w/a88e57/32.png) [@wishiwasayoyoexpert](https://forums.yoyoexpert.com/u/wishiwasayoyoexpert)\ **Post date:** [April 10, 2016, 4:50pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/5 "2016-04-10T16:50:06Z")
> [@yoyoguy2017](#): > > by thermally fitted, do you mean welded onto the yoyo? Welding is way too inconsistent for yoyos as it adds quite a lot of material and doesn’t add it evenly enough. ---
**Author:** ![\_RTD\_alecto](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/_rtd_alecto/32/1336_2.png) [@\_RTD\_alecto](https://forums.yoyoexpert.com/u/_RTD_alecto)\ **Post date:** [April 10, 2016, 10:45pm UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/6 "2016-04-10T22:45:51Z")
you dont weld the rings onto the yoyo. its a press fit. ---
**Author:** ![jhb8426](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.yoyoexpert.com/jhb8426/32/631_2.png) [@jhb8426](https://forums.yoyoexpert.com/u/jhb8426)\ **Post date:** [April 11, 2016, 12:32am UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/7 "2016-04-11T00:32:40Z")
> [@yoyoguy2017](#): > > by thermally fitted, do you mean welded onto the yoyo? What it means is that you machine to an interference fit or very tight fit. To attach the ring you heat it which makes it expand. While it’s heated you press it on to the other part. When it cools it will be attached very firmly. No disrespect intended, but it’s not a novice design project. ---
**Author:** ![kyo](https://avatars.discourse-cdn.com/v4/letter/k/df705f/32.png) [@kyo](https://forums.yoyoexpert.com/u/kyo)\ **Post date:** [April 11, 2016, 3:29am UTC](https://forums.yoyoexpert.com/t/bi-metal-cad-designing/80018/8 "2016-04-11T03:29:00Z")
Thermal fits in the yoyo world are very rare… as far as I know nobody has actually released a yo-yo made this way. I have a yo-yo coming out soon that does it, but most others are just a very tight press fit. Kyle