Statapults (catapults for statistics)

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Project by Brodan posted 10-23-2017 12:27 AM 2391 views 1 time favorited 9 comments Add to Favorites Watch

Set of catapults for teaching six sigma class. I retired from my job early this year and now do consulting. My previous company owned a set of these that I used when I taught six sigma classes for them. Now need a set of my own and didn’t want to spend the $250.00 apiece that they sell for. Had some red oak, less than $50 for all the hardware, scales and protractors. Finished with a coat of amber varnish and a coat of wax.

And a good excuse to get into my new much smaller shop (downsized last year in anticipation for retiring).

-- Dan, TN

9 comments so far

View kdc68's profile


2985 posts in 3013 days

#1 posted 10-23-2017 01:09 AM

Pretty nice ! Congrats on retirement.

-- Measure "at least" twice and cut once

View Brodan's profile


169 posts in 2039 days

#2 posted 10-23-2017 02:41 AM


-- Dan, TN

View ohwoodeye's profile


2372 posts in 3890 days

#3 posted 10-23-2017 01:19 PM

Retiring… I’m downsizing my shop. That sentence doesn’t make sense to me.

-- "Fine Woodworking" is the name given to a project that takes 3 times longer than normal to finish because you used hand tools instead of power tools. ----Mike, Waukesha, WI

View helluvawreck's profile


32119 posts in 3603 days

#4 posted 10-23-2017 02:30 PM

It looks like you did a very nice job on these. Congratulations.

helluvawreck aka Charles

-- helluvawreck aka Charles,

View Bill_Steele's profile


697 posts in 2468 days

#5 posted 10-23-2017 02:59 PM

Nice job! There are alot of adjustment options—I assume to dial in a specific range or for different weight objects to be thrown? How do you use these in your teaching process?

Thanks for sharing.

View Richard Campbell's profile

Richard Campbell

7 posts in 1187 days

#6 posted 10-23-2017 03:20 PM

View Ivan's profile


15854 posts in 3604 days

#7 posted 10-23-2017 04:11 PM

Good cooperation between woodworking and engineering.

-- Ivan, Croatia, Wooddicted

View Brodan's profile


169 posts in 2039 days

#8 posted 10-24-2017 12:35 AM

Thanks all!

Mike, retiring for me meant downsizing to a smaller home without space for a shop. Did put in a 12×28 building, 10’ of which is storage, only leaving 12’x 18’ for a shop.

Bill, I teach six sigma. As part of the training students will select the factors (adjustments) they think most affect the distance (critical factors) that the catapult fires, test fire the statapults a limited number of times and document the distances. Entering what they learn in a statistical software package they develop a predictive model. Once their model is complete I randomly select 3 distances between 20” and 120” and they enter the distance in the software which tells them where to set each adjustment and they fire a ball at a target set at each distance. Typically have 2 teams compete, thus the two statapults. Having both fixed (stop holes, number of rubber bands, ball type) and infinitely variable adjustments (pull back angle and front post tensioner) gives the students plenty to think about. When the students develop a solid predictive model they are amazingly accurate over the entire distance.

-- Dan, TN

View bushmaster's profile


3938 posts in 3019 days

#9 posted 10-25-2017 02:57 PM

Very interesting what they are used for. Well done reproduction.

-- Brian - Hazelton, British Columbia

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