Pump Assembly Page

Links and photos provided here are intended  guide you to through the steps of assembling the component  parts of the treadle pump.

This page is new and obviously under construction. Readers are warned that the plans linked by this page and the information on this page are preliminary and subject to change without notice. So, until we've got a better handle on what we're doing, feel free to visit and look around. We'll remove this notice when the information here has firmed up to the point that it's considered dependable.

The photo is an assembly drawing of a complete pump. In time, this page will detail the steps necessary to construct a similar pump from it's components.


 

 Fig. B1

This shows the metal parts almost finished. One of the straps has yet to be bent. The holes in all the bent metal parts should be drilled prior to bending. If you click on the photo to enlarge it, you should be able to see two scribed lines in the unbent strap. The strap is placed in a bench vise with one of the scribed lines line at the top edge of the vice jaws.


 Fig. B2

The strap is bent by striking it just above the vise jaws with a large hammer. If your hammer is big enough and you're vigorous enough the parts should not need to be heated in order to bend them.

 

 

Fig. B3

This photo shows the wood components cut from 2x4s and 2x6s. The parts have been cut to the correct size, but haven't been drilled with the required holes. From top to bottom, left to right the parts are: pulley mast, pulley support, front outboard vertical supports (2), front center vertical support (1), rear vertical supports inboard and outboard (3), treadles (2), and at bottom, pump bases (2).


 

 Fig B4

This photo shows the plywood parts, laid out as they were cut from a 2' x 4' piece of half inch plywood so as to minimize waste.

 

 Fig. B5

The treadles are drilled through on edge. It's important to drill this hole as nearly square as possible. Here,one of the treadles is being drilled on a drill press. The treadles are clamped together to help keep either from tipping.


 

Fig. B6

If a drill press isn't available the device shown here can be used. It's called a drill guide for doweling. It clamps to the board being drilled, and centers itself. Keep in mind that it's a guide, and if not used with care, you can still drill a crooked hole

 

 

 Fig B7.

Here are the two clamp rings. One  has already had its' center cut out using the jig saw. The large hole provides a starting place for the jig saw blade. The center hole could also be cut using a keyhole saw or a coping saw. The center hole was marked using a scrap of four inch pipe. A compass could also be used. The wood rasp was used to smooth out the edges of finished hole.

  

Fig. B8

This shows one of the treadle pump bases which has a two inch diameter recess bored in it's top surface. This recess can be omitted. It reduces the stresses on the base of the pump cylinders by increasing the area that supports the bases, and makes the bases less prone to slip around while the pump is in use. So, unless it just seems like a lot of troubIe, I will encourage you to include this step. I made this recess using the Forstner bit in the photo. The recess can also be made by first boring a hole with a hole saw , and chiseling out the inside of the recess with a wood chisel.


Fig. B9

The clamp rings are used as patterns to mark four holes on the treadle bases that will later allow all thread rod to pass through the bases. If you click to enlarge the photo you can see where the left hand base has been marked. The bases and rings should be marked left and right as shown so they will be assembled correctly later. Whenever two parts are cut and drilled by hand there will always be some variation from part to part. Using the rings to mark and drill the bases will avoid alignment problems later.


Fig. B10

Here I've started fastening the plywood braces to the treadle bases. Screws or nails and a waterproof glue should be used. I'm using Titebond III, which is relatively cheap, strong and really waterproof once completely cured, as advertised. Predrilling the plywood before installing the screws helps prevent splitting. The longer brace goes towards what  will be the rear of the finished pump.


Fig. B11

This shows the bases with the inside braces installed. Notice where the bases were marked left and right in a previous step.


 

Fig. B12

 Here the bottom strap that supports the mast has been attached to the center front vertical with two deck screws. This step can be done later, but it's easiest before the rest of the wooden components are assembled.

 

 

Fig. B13

At this point, the two bases are fastened to the center vertical supports with glue and three screws through each plywood brace on each side.

  

Fig. B14

The outboard vertical supports are fastened to the remaining plywood braces with more glue and four screws each. Notice the screws in the bottom corners are offset, and there is an extra hole.

 

 

Fig. B15

This closeup of one of the vertical/brace assemblies shows the extra hole more clearly. This hole should be drilled all the way through the plywood and 2x4. You'll see why in the next photo.

 

 

Fig. B16

The  braces and outboard verticals are fastened to the bases using long screws or nails through the holes drilled in the previous step. The screw or nail should be long enough to pass through the vertical, the plywood brace and well into the base. The screws used here are four inches long. A piece of 3/8 inch diameter steel rod has been passed through the top holes in the vertical supports while the supports are fastened to help insure proper alignment.


Fig. B17

The end brace is glued and screwed in place on the front of the pump.


Fig. B18

Next, steel tubes that serve as bearings are glued into the holes drilled earlier into the treadles. Two part epoxy is used to secure the bearings. The bearings should be carefully centered in the treadles.


 

Fig. B19

Here the treadles have been installed at the rear of the pump. They're held in place by a 3/8 " diameter steel rod cut to a length of 20 inches. The rod has been cross drilled through each end to allow a cotter pin to be installed to hold the rod in place. A washer is installed on each end of the rod, and on the outboard ends of the treadle bearings. 

 

 

Fig. B20

The front strap that supports the mast is installed with a 4 1/2" long steel rod held in place with cotter pins through holes cross drilled in the rod. A wood rasp is used to radius the back side of  the wood center support to allow the mast to rotate from the upright to the stowed position without binding. This radius has been highlighted with black marker in the photo.At the bottom of the photo the bottom strap that supports the base of the mast can just be seen.


Fig. B21

The mast is installed by passing it through the front strap, and pushing it down onto the bottom strap.


Fig. B22

The pulley support fits in a recess cut in the mast. This recess should be cut so as to make a tight fit with the support. The joint should then be glued and screwed together. The crosspiece goes in front of the mast as you stand on the pump.


Fig. B23

Pulleys are attached the pulley support with eye bolts and Nylock nuts. Note that the bail that holds the pulley has been drilled and a cotter pin installed to keep the cable in it's proper place on the pulley during storage and transport.


 

Fig. B24

 The pump cylinders are held in place on the treadle bases with all thread rod secured under the bases with "T" nuts.


 

Fig. B25

 Here the pumps have been installed on the treadle bases using the clamp rings made earlier and all thread rod installed in the previous step. The check valves have been installed, using plenty of thread tape. The valves have been marked with arrows showing direction of flow, because I get confused.


 

Fig. B25

The steel cable connecting the two treadles is fed through the pulleys and secured to the treadles using eye bolts and cable clamps. The length of the cable should be adjusted so that when both treadles are even with each other, they are also horizontal, which is what I'm trying to show with this photo.


Fig. B26

The wrist joints that attaches the pistons to the treadles are made up from two angles, one spacer, an eye bolt, joiner nut and two jam nuts. Here one joint is still loose to show the spacer inside the eye of the eye bolt. The joint is held together by a 3/8" bolt and a lock nut, drawn tight. The spacer allows the eye bolt to move freely.


Fig. B27

This shows a piston assembly composed of two leather cup seals, three PVC discs, and nuts and washers arranged on a threaded rod in the order that they are assembled. To the right in the photo is a finished assembly. The PVC disc in the center of the assembly is cut to fit as closely inside the pump cylinders as possible without binding. The two outside PVC discs are seal retainers. These are considerably smaller than the center disc, their diameter depending on the thickness of the leather used to make the seals. They should be small enough to allow the leather cup seals to move in the cylinders without binding. The retainers are rounded on one edge using a wood rasp to prevent cutting the leather cup seals. Nylock nuts are used to secure assembly parts on the threaded rod. More information on pistons and leather seals is here.


Fig. B28
This is a complete piston and rod. The threaded portion that holds the piston and seals is about four and a half inches long. This dimension will vary somewhat depending on the rest of the hardware. Length of this assembly is about seven and a half inches from the center of the eye bolt to the center of the piston. This length can be adjusted by moving the Nylock nuts on either side of the piston.

Fig. B29

The pistons are fastened under the treadles with four screws through the angle brackets. Proper location is for the rod to cant just slightly forward as you see here. It helps to get the location right if you position the rod as shown, and clamp it in place. The treadle can then be pulled up and over so that it's bottom side up, and the screws installed.


Fig. B30
All that remains is for the one inch ID heater hose to be attached. The shorter hoses are four inches long. The longer hoses are one foot long. If you look closely at the two hoses where a "T" has yet to be installed there are springs sticking out of them. The springs are made of 14 gauge galvanized wire, and keep the suction lines from collapsing. The pressurized side of the pump requires no springs. More information concerning the springs can be found at this link.


Fig. B31

The plumbing is complete here. Each "T" has been clamped to a wooden cleat to provide mechanical support and isolate the rest of the plumbing from mechanical stresses. 


Fig. B32

If you are building a pump, at this point you should have something that looks like this. Here the mast is stowed for storage or transporting the pump. The box under the pulley support is a guard to keep fingers out from between the pulleys and cables. Instructions for constructing the guard are here.

 

 Fig. B33

Finally, here is the finished pump with the mast up ready for use.