Shrimp Pump

This is a simple Shrimp Pump. This is the first version so feel free to add and comment! 

You can modify this to be a lot of different things. Pneumatic cylinder, Squirt gun, Aquarium pump? 

(Edit 2/2/24, Added holes to the Top Cap, there was an issue with back pressure on the previous version)

You will need:

1 x 2" section of PVC. Choose your length. I used a pre cut section from the store

1 x ½" section of PVC, Should be the same length as 2" section

1 x ½" T slip fitting for the handle. You can get as crazy as you want here. I have seen people use threaded T and small sections of threaded pipe to make “wide” handles 

1 x O-Ring. I'm still figuring out the ideal one, The O-ring groove is .125" wide and .2" deep. I left a little extra depth so you can wrap some string or teflon tape to “adjust” the o-ring fit. 

Assembly:

I printed all parts with 100% infill and organic supports. This is a tool that will get a lot of strange loads and be abused in the sand and salt so I figured go all out. 

Step #1 : Top cap instillation

I supplied two Top cap sizes

• Slip: Slightly undersized (2.0") to be glued or screwed in place
• Press: Slightly oversized (2.1") to be pressed in after heating 2" PVC pipe with heat gun to soften the pipe to deform to the cap. This is the method I used and it works like a champ. 

Step #2: Plunger

Glue Plunger to end of ½" PVC. I used super glue, however you may want to consider what material you are printing with to choose an adhesive that works best for you.

Install the O-ring. This will take a little experimentation on your part to find the perfect fit for your printers tolerances and the PVC pipe you are working with. 

Step#3: Handle

Insert the glued Plunger and ½" PVC into the 2" PVC pipe, so that the ½" PVC pipe passes through the Top Cap.

Install handle to end of ½" PVC pipe. You can glue this in place with PVC glue or you can screw this in place with a small grub or wood screw. If you screw it in you will be able to remove the piston for servicing. If you glue the top cap and handle you will not be able to service the Piston or O-ring.

Step#4: Catch some Shrimp! Then catch some dinner!