Desperately need everyone’s help with designing large sprockets with 100 teeth or more (these are sprockets with diameters close to 13 inches) for use with #25 chains. We’re using these sprockets to turn a large carousel for our ball shooter.
We’ve tried using online socket designers to generate the CAD files for the sprockets. However, the sprockets that come out are always off by a bit. They generally fit the #25 chain for 4-8 links and then you can see that slowly the chain no longer fits properly.
From a technical perspective, does anyone have experience designing large 100+ teeth sprockets or using sprocket generators and may have some experience to share with us? Thank you very much!
I’ve had a sprocket design tutorial in the works for some time now. I’m going to post it sometime soon, but otherwise date TBD. While I draft that, are you a SolidWorks 2019+ user? I can make a configurable-enough sprocket for you in the meantime. If you give me a pitch and tooth count, I can also make a STEP with the correct sizing.
Get the pitch diameter using pitch/sin(180/# of teeth)
Then pattern the same amount of circles as teeth around the pitch diameter and then use arc for the ends of the teeth
I’ll note that this profile does work, but it’s not the same as you see on COTS sprockets - they have a slightly different profile which has shorter teeth and broader roll-in curves.
There’s a possibility the profile is not off. Are you machining the sprocket out of .125" material? If so it is a little tight to the #25 chain (.110") We encountered this, it would pop the chain off, and we thought it was a bad profile, but after tapering the outer perimeter (the teeth) on a belt grinder it worked perfectly.
