White Paper Discuss: Dr Joe's Chain Path Visualizer

Dr Joe’s Chain Path Visualizer by Joe Johnson

This is just a simple tool that I have cleaned up for public use. The title says what it does. Read text I typed when I uploaded the file if you want to know more.

I encourage any other veterans who have useful (or even semi-useful) spredsheets to spend a bit of time to make them available for others to use.

Joe J.

Just curious if anyone is actually using this spreadsheet/visualizer.

A lot of folks have downloaded it, but I have yet to receive any feedback one way or the other.

Teams should be getting to the point where they are actually laying out chain paths. I hope that this tool helps folks think about routing and in particular think about tensioning systems for you chain (and, most importantly, making sure you have enough travel in your tensioner).

As always, Feedback is welcome.

Joe J.

Just noticed it this morning when you posted. (Things have been hectic, and whitepaper reading has fallen through the cracks.) I’ve been wanting something like this recently, and so I downloaded it and rushed to try it out.

I modeled some of 229’s drive chain, and it worked out GREAT for me.
This is an incredible tool, that I will no doubt use like crazy.

The functionality is excellent, but my ONLY criticism is the user interface takes a second to figure out. I managed ok, but newbie designers may have issues. (Though I guess one could argue - if I can do it, anyone can ;))
Perhaps (whenever you get a spare moment - sometime in 2010) you could do a revamp which makes it easier to use for rookies. Until then, I’m sure we’ll all manage just fine.

This is definitely a great tool, I urge all mechanical designers to check it out.

Attached below is a pic of one of 229’s drive chains. Joe’s sheet helped me gain new insight into my tensioning system (as he promised it would).


Brilliant visualizer, Dr. Joe! Gone are the days of randomly estimating chain lengths and tensioning it at the last second. A must-have tool for the “chain gangs” out there.

i used it to lay out simple two sprocket setups…just using the goal seek to optimize the center distance. dennis is using it for his drivetrain calcs and so far things look great.

would it be possible to add a field which display the center distance between sprockets? i don’t mind using the pythagorean but a field which did it for you would be swell.

I’ll have to get my team in-touch with this application. Nice work

Good idea. I will think about it and see what makes sense. I am thinking that I could add a column that shows the distance to the sprockets before and after the current sprocket. Should be a piece of cake.

Joe J.

Nifty tool. It should probably be noted for the layman that one goal of chain and sprockets is to achieve 180 degrees of engagement per sprocket. But when you can’t, I’m curious if you could add to this, such that you key in the motor torques and assume stall. Then let the spreadsheet estimate the needed amount of tooth engagement at each sprocket (depending on radius etc). Maybe you could indicate which is the drive. Now thats the deluxe model!

Also I noticed on the top of the page you’re saying to only edit the green fields. But you need to “green” the “Nspr” (number of sprockets) field in case we don’t have a 6 sprocket setup.

Also users note:
make sure to zero out the extra fields beyond the number of sprockets needed

The spreadsheet calculates “Nspr” based on the number of spockets you enter (or it WOULD if you don’t enter a number in by hand :slight_smile:

You are correct however in that the tool has some ease of use issues.

Joe J.

P.S. I know of no rule of thumb that say the goal is to wrap 180 around each sprocket. I have no objections to 180 degrees of wrap, but many times I live with much less. I typically am more concerned with the number of teeth engaged than I am the wrap angle getting to 180. For what it is worth…

Not sure what magazine this is, but the chainpath visualizer is definitely in it.

After so many uses, I’d recognize it anywhere :wink:


Based upon the previous page (photo), it is Servo magazine’s Nov. 2008 issue.