Idler Pulley Post
Note: Sorry for the misleading that this idler post used directly with timing pulley as Idler. No, it is Not good to work with timing pulley directly BUT to be used together with an idler pulley which is ball bearing built-in. But there is No problem to take the should bolt as a shaft to fix a bearing or idler as a slave axis.
The price marked is 1pcs D8*20*M6 Shoulder Screws as Idler Post.
RobotDigg are trying to cost down your Belt&Pulley Drive solution.
This shoulder screw or stop screw is another idler pulley or belt tensioner solution has been adopted by CoreXY, to 8mm bore pulleys, GT2 Pulley 20 Teeth 8mm Bore and GT2 Pulley 36 Teeth 8mm Bore.
It works much better with F608ZZ Ball Bearings as idler pulley.
There is OD6*16*M5 Idlder Post available to work with 6.35mm bore Timing Pulleys as IDLER.
http://www.corexy.com/corexyr1/index.html
CoreXY is using a GT2 16 Teeth Pulley and a 5mm OD, 20mm L, M4 Shoulder Screw as Idler Pulley Post.
There are sizes of should screws: smooth shaft 6mm, 10mm and 12mm. MOQ is 50pcs, please contact us by email for a quote.
Shoulder Bolt
Shoulder bolt is also known as shoulder screw, stripper bolt, or stop screw which can be used to work with flange ball bearing or ball bearing as idler post.
Idler post means the axis or shaft is a slave shaft, the bolt itself is just working as a post that is steady, but the idler will spin together with the drive shaft. The drive axis is connected with the slave axis using a timing belt or v-belt, chain, and so on transmission parts. Idler can be ball bearings or timing pulleys with ball bearing press mounted.
Shoulder bolt in fact it really owns two shoulders. The first one is the socket hex head to the main shaft or the post part. The second shoulder is the post shaft to the mounting screw, so if the shaft is 5, as usual, the screw will be M4.