are "lantern" sprockets necessary

[Tmoose]

I was thinking of using a length of 50 roller chain in place of a convex curved rack that is part of a manually adjusted, occasionally adjusted, burner air flow control system.

I understand the standard sprocket tooth form is necessary for the chain to wrap around a sprocket, but I am expecting clearance, not binding, if standard parts are used.

These guys talk about the necessity of a "lantern" sprocket tooth profile when using a roller chain as a rack.

http://www.wippermann.com/Sprockets/Lantern-gear-sprockets/1_148.html

Is that requirement for nice accurate positioning, or to relieve binding ?

thanks,

Dan T

 

[Occupant]

If your requirement is absolute linear motion, that's what you need. Otherwise - no.

 

[3DDave]

In using chains to replace racks I've seen idlers used to increase the engagement, such as on the Blacktoe CNC.

If it's just a drop in then the lantern gear teeth look necessary to survive long.

It looks like this system is also referred to as pin-gear drive.

A one page comparison page

http://sei.ckcest.cn/product_img/100001/5403/67180/document/142.pdf