Pitching Machine Support Block

I was pulling out our pitching machines last minute and discovered that the support block was missing on one of my machines and another was in bad shape.    This Support block is the part attached to the pull handle that when you spring load the throwing arm, this part holds the tension on the pull handle to pitch the ball.    

I designed and tested this on a Louisville Slugger Blue Flame Ultimate Pitching Machine 45 (UPM45) but i am fairly positive that it works on the upgraded Black Flame UPM50 as well.

This is the piece i was replacing:  https://sluggertraining.com/collections/replacement-parts/products/louisville-slugger-upm45-nylon-support-block-with-triangular-knob

I have 3 versions of this,  All 3 i have being used by machines 4 nights a week.   So far all 3 are still working and not showing any signs of damage/breaking at all.  I Printed mine with Bambu Labs PA6-CF, the factory part is made of Nylon so that is what i went with.   Your mileage will likely vary if you try PLA and it softens up in the heat etc.

3 Versions to choose from:

PM-Solid - is just a solid block with a hole cutout for the threaded insert
PM-AluminumStock - this has a negative space to insert some aluminum stock to strengthen.  Pause your print job at layer 38 to insert yours if you try this one.
PM-Cylinder - This is Solid, but with 5 small (2.6mm diameter) cylinders running lengthwise along the bottom.   

The Original Part uses M6 threads so all versions are designed to use M6 Threaded Inserts (https://www.amazon.com/ruthex-Threaded-Insert-M6x12-7-25pcs/dp/B09ZHBLGKM).   The OD of the inserts i used is 8mm so i made the mounting hole is 8.1mm in diameter and 25mm deep.   There is plenty of space "underneath" the threaded insert for more flexibility on your M6 bolt length and the diameter allows plenty of material for the insert to grab on to without just pushing a clumping pile underneath the insert.

M6 Bolt with a Hex Head is what i used, 40mm in length and i simply printed a knob.   Any knob should work but the exact one i used in my rush to get something working. can be found on Makerworld if you search "Knob for metric screw m5 to m12" (i'm not going to link to makerworld on printables!)  

The Aluminum Stock part i used in a simple piece of aluminum that is 1/4" square (I am american so thats the sizing i am able to buy locally, i just prefer to design in metric)

Print these laying down flat,  If you printed vertically, your layer lines would absolutely be an issue.  I suggest using the 3mf file for my print settings.   Otherwise i used a .4 nozzle with .2 layer heights.   Printed this with 6 walls,  6 bottom and top layers as well as 85% cubic infill.  There is a LOT of tension put on this piece so save yourself the heartache!   Its probably not worth buying the inserts/bolts for this piece if you only need one.  But if you already have the inserts etc absolutely you should give it a shot.

SO as of now,  each version is on a machine and all machines having 12-18 hours of usage on them and they are all holding up.  I will try to update this if/when i get one to fail.

Please share your results, success/failure and what type of filament you used.