Homemade star pump

[808goboom]

I made this homemade star pump.let me know what u guys think and if it'll work or any improvements I can make to it.i haven't tried it yet.

 

Click this link for a video.

http://www.youtube.com/watch?v=lmW6KbGoUAk

[mathiasxx94]

Nice pump! But did you use paper or cardboard? It might get very crumbled after a while, what about using fiberglass to make a pipe around the wooden dowel?

[Col]

Brass hose barbs make nice star pumps, drill out the shoulder inside the threaded part and add a brass rod.

[Pretty green flame]

I would suggest using some PVC or Aluminium tubing, much more durable than paper tubes. The wooden rammer is OK.

 

I made these pumps in about 30 minutes on a lathe. Some aluminium tubing that set me back 0,50€ and some HDPE rams. Price per unit would probably come around to 2-3€, cheap but effective, a depth gauge would also be nice but I haven't come around to making it yet. They are 28mm ID made for 30mm single shot items.

[Shadowcat1969]

Brass hose barbs make nice star pumps, drill out the shoulder inside the threaded part and add a brass rod.

 

Yes, I've made a few using these, you find them at Home Depot or such, usually in the plumbing section, and there are a lot of sizes to choose from. You can make a solid rammer for them easily using hardwood dowel.

[Mumbles]

I agree that you'll probably have trouble ejecting the stars if that is paper as it appears. I'd also suggest plastic or metal tube. The composition will not stick to them like it will for paper.

[californiapyro]

What size is that, 1/2"? If so, I'll send you an aluminum ramming sleeve, just for your ingenuity.

[Chuleo]

I wonder why no one ever mentiones the very cheap and simple seringue starpump? I've been using them pretty long time when I didn't have a star plate. They are available, come in various different sizes and very easy to clean.

I've used this one:

http://eshop.semadeni.com/custom/pic/jpg280/0859.jpg

for pumped comets 2" x 2" in size. They work perfectly and the bigger ones can even get rammed.

(They are a little less than 2" so they fit perfectly in a 2" mortar)

[Zumber]

yes...

syringe works well for me and it is less expensive too.:-)

[ianagos]

I used to use PVC with with a hardwood dowel.

[Col]

I`ve used syringes, they work well. The main downside is they get torn up pretty fast by metals and the comp has to be on the wet side of damp.

I prefer to use hose tail/brass rod pumps these days. The drier comp makes it less messy, no cutting so its quicker and the stars are well compacted with a uniform length. It takes less than 30 minutes to make the pumps.

File a slot down the hose barb, drill and tap a hole for a pin in the side of the brass rod and hot glue a 1.5" od plastic handwheel to the top of the rod. The handwheel fits comfortably in the palm of your hand (no pain) and it allows you put your bodyweight on the pump.

Fill the pump by pressing it into damp comp, compact it with your bodyweight then twist the handwheel to align the pin with the slot and eject the star.

When you get into the swing of it you can pump 10-15 stars a minute.

Edited November 16, 2013 by Col

[ianagos]

The way I did it was to cut the tube to a certain length. Like 2x diameter and fill it flush to the top the insert rammer and hit with hammer or press by hand depending on the comp. this made perfectly uniform stars (charcoal based mostly d1) tha dried in a day rock he'd because very little water was added. Now I have a lathe and plan on making some much better pumps. Also want to try som rocket tooling.