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0.375OD tubing is relatively large and will result in a fairly large pump housing I think. If you need a different squeeze tube to the one you have, I found these people good to deal with:
JACK 620,
Have you seen any drawings/pictures showing details of this type of pump? I am at a loss as how to fixture the inlet/outlet tubing ...attaching, connecting etc.
Ray M
 
JACK 620,
Have you seen any drawings/pictures showing details of this type of pump? I am at a loss as how to fixture the inlet/outlet tubing ...attaching, connecting etc.
Ray M

Hi, the tube isn't fixed to anything, its one continuous length. Its held in place by the two diametrically opposing spring loaded rollers. There are two basic variants of pump. Those that can be reversed and those that can only run one way. Most medical types can only run one way.
 
Hi, the tube isn't fixed to anything, its one continuous length. Its held in place by the two diametrically opposing spring loaded rollers. There are two basic variants of pump. Those that can be reversed and those that can only run one way. Most medical types can only run one way.
thank you Baronj
Ray M
 
Hi Ray M and others interested in worm gear fabrication

I found the exact YouTube file that very nicely demonstrates an easy method of making a worm gear. It is at


Notice that this is done with a standard tap and generates a worm wheel with a standard tap profile. This allows you to use a standard threaded rod for the worm shaft. You do not even have to cut a thread on a rod. The method shown in the video means you do not need a thread cutting lathe or thread cutting skills.

If you want to try something more difficult, and versatile. you can take a look at this video.

Note that the use of the index mechanism is to hog out a rough profile. The wheel does not yet have the proper profile , tooth angle, or circular depression required for a proper worm wheel.
This is done with the cutter you have made at the end of the video.

Have fun,
Henry K
 
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Hi Ray M and other guys,

I located two very nice YouTube videos on this topic.

This one does not even require a thread cutting lathe or thread cutting skills.


It has the further advantage, for easy fabrication, and of enabling the use of standard threaded rod for the worm screw.
Keep in mind that there is a lot of sliding friction in any worm gear drive and especially when you use threaded rod or a home made worm. If you want, after assembly, put some lapping compound in the mechanism to smooth out the rough spots. Clean it VERY thoroughly afterwords before using it for you application - even to using soap and water.

A more elaborate fabrication video, but still fairly easy video is at


This has the advantage of having an Acme thread profile. It does require an Acme thread gauge to make a proper tool bit profile, a thread cutting lathe, a milling machine, and a spin fixture or dividing head.

This would be a thread profile of what is used in the automatic clutch feed mechanism of a industrial lathe like Logans and some South Bends. Note that this is NOT the same as using the thread cutting mechanism with a very fine feed gear setup like that used on an Atlas, some South Bend or similar non-clutch feed lathe. They use the lead screw and half nuts.

I am going to try the first one above just for fun. I have no application in mind except for "Show and tell" in the Mechanical Engineering lab I teach at the University where ME students become familiar with how things evolve from drawings to hardware.
 
Hi Guys,

Those videos show exactly the technique that I used to cut the worm wheel that I showed in my pictures. Only in my case I only cut about 25% of the diameter of the wheel.
 
A Rotary Peristaltic Pump is a tube pump that dominates the area. Medical drug pumping and chemistry are the main customers. The reason is the prevention of leaks and contamination. However many ink jet machines use a peristaltic. I recovered on from a printer that failed. Want to pump fluid out of a bottle a trigger operated peristaltic pump is the way to go for do it yourselfers. Need a rubber tube that goes to the bottom of the bottle and a check valve. The trigger folds the tube over a rounded surface. I would push the round face into the tube so the two ends can be fixed. Also with two check valve all you have to do is bend the tube to get it to pump since bending will cause a collapse somewhere in between the two valve both permitting flow in one direction.
Hobbing with a tap is possible and much more difficult with an ACME thread. The biggest problem not mentioned above is the problem that the lead or pitch is fixed on the tap but for a gear is fixed for angle but distance is the radius times the angle. Thus as the tap cuts into the blank the angle changes since as I said pitch is fixed on the tap. Thus as each deeper revolution cut is complete they will not match the previous cut. At some point the previous cut pulls the next cut into line. The effect is that the number of teeth on the blank can vary by one tooth.
Go look at the taps used to cut ACME threads. What you will see is first a screw shaped tap making V cut and behind that to use the V cut as a guide the squarish ACME tap. Cutting a gear will require this same approach for the free wheeling hobbing.
 

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