HydraForce PFPD assembly

HydraForce Inc. August 20, 2013 Page 1

HydraForce PFPD assembly

HydraForce Incorporated

Henry Brewer


About

The HydraForce Portable Fluid Power Demonstrator was designed and built to showcase

hydraulics and introduce people to fluid power using the unit as a demonstrator and an

educational tool. The unit itself is a small sized, electronically controlled, self-contained, claw

arm capable of demonstration with a limited range of motion.

Much of this guide will be based off of the Portable Fluid Power Demonstrator (PFPD) v.2 –

Electronic Control Arm Trainer which was done by the Center for Compact and Efficient Fluid

Power and Purdue University. A link to the initial project can be found here. Direct excerpts

from the assembly document will be used in this document.

A comprehensive parts list can be found at the end of these instructions including parts needed,

quantities, and links to purchasing where applicable.

The fabrication and assembly in this guide are open to changes and modifications, and for each

step there are many ways to go about it. This guide will attempt to cover all of the methods you

can use, but will focus on the methods used in the initial construction.

http://www.ccefp.org/-13


Arm and Claw Fabrication

This step goes through the sub-steps to make the Arm and Claw. Recommended metal

machining tools including: a drill press, a band saw, and a vice as well as basic tools such as

hammers, files, and a hack saw. Dimensions can be inferred using all of the following pictures.

1: Building the Arm Mount

To build the Arm Mount, we first need a piece of 1” x 1” Box Tubing cut to 9” long. Next, drill

the piece as shown in Figure 4.

Note: It is also a good idea to be sure to file down all sharp edges and holes or use a wire wheel

to take off burrs.


2: Building the Arm Base

To build the Arm Base, we first need a piece of 1.25” x 1.25” U-channel cut to 12.5”.

Next, cut and drill the piece as shown in Figure 5.

File edges and holes and round sharp corners.


3: Building the Boom

To build the Boom, we first need a piece of 1” x 1” Box Tubing cut to 16.5”.


File edges and holes.


4: Building the Stick

To build the Stick, we first need a piece of 1.25” x 1.25” U-channel cut to 9.75”.


File edges and holes.

Building the Claw

The claw consists of two parts, a front and back. The front is the moving part while the back is

stationary relative to the stick.

1: Building the Claw Front

To build the Claw Front, first cut the steel plate down to a 3” x 7” piece


First cut out lines for the bent tabs as shown as well as the

triangle design using a band saw or hack saw and bend over

dotted lines by sticking the claw partially in a vice and pounding

over the small support parts. Bend to 90°.

Note: in order to make the horizontal cut you may need to

drill holes along the line until you can fit a hacksaw in to

cut the rest.

Next, using a bending press or a vice and hammer again,

bend the 120° angles of the claw body. Be sure to bend

them in the correct direction by checking Figure 8 again.

Finally, drill the two holes through both tabs.


To build the Claw Back, first cut the steel plate down to a

3” x 7” piece.

First cut out lines for the bent parts as shown as well as the

claw shape and bend over dotted lines by sticking the claw

partially in a vice and pounding over the small support

parts. Bend to 90°.

Next, using a bending press or a vice and hammer again,

bend the 120° angles of the claw body. Be sure to bend

them in the correct direction by checking the Figure 10

again.

Finally, drill the two holes through both attaching tabs.


Bracket Construction

Three brackets will need to be made for the rear mount of the stick and bucket cylinders and the

rod end of the boom. When fabricating the brackets, use the rectangular steel tubing. The bracket

dimensions are shown in Figure 3. Two 3/16” holes and one 1/4” hole will need to be drilled as

shown in Figure 3. After the holes have been drilled, round off any sharp edges.


Arm Construction

Review the arm below to get a good idea of where each of the parts go. Assemble the Arm from

the bottom up. First attach the Arm Mount to the Arm Base with two ¼” bolts and nuts. Next,

bolt the Arm Mount to the board through the bearings using the large ½” bolts and the

connecting nut.

Next, slide the Boom between the walls of the Arm Base and line up the 3/8” holes. Use a 3/8”

bolt, nut, and washers to connect the first two parts of the Arm. Note: It will fit tightly, but a few

drops of light oil should loosen it up. Next, slip the Stick over the other end of the Boom and

secure it with another 3/8” bolt, nut, and washers being sure that the Claw end of the stick down.

Then attach all three of the Angled Brackets to the Boom and the Stick with bolts and nuts.

Finally attach the Claw. First attach the Claw Back through its bottom hole with bolt and nut. Then

align the holes in the end of the Stick, Claw Front, and Claw Back for one bolt to go through.

You are now ready to install the pistons. The three triangle brackets should have the cylinder

ends fix in them using bolts and nuts. The base end of the boom cylinder can be fixed with a bolt

and nut. The loose end of the stick cylinder should be fixed to the back of the stick using a bolt

and nut. Finally, the claw end of the claw cylinder can be attached with a bolt and nut.


Manifold Information The manifold will come preassembled but below you can find some basic information about the

manifold layout and assembly.

The HydraForce number for this manifold is HF86307-13.

The Picture below shows the hydraulic system as a whole including reservoir, pump, and

cylinders.

The manifold is the key component in the hydraulic circuit. In the picture above the manifold is

what is within the dashed lines. The manifold contains internal plumbing lines as well as all the

valves which direct flow to each hydraulic cylinder. The manifold has an inlet port which is

connected to the outlet of the hydraulic pump. This allows the hydraulic fluid to create a pressure

in the manifold which releases when operating the valves.


Joystick Box and Control Box The electronics in the project are organized into two separate project boxes, one box for the two

joysticks, and another for the other components that allowed the electronics to function.

Below you will see the AutoCAD drawings for both the electronic component box as well as the

joystick control box. You can fully view both by zooming in.

EVDR0201

1

Power in -

Ground

Power in +

Signal in

Sol B -

Sol B +Sol

A +

Sol

A -

EVDR0201

2

Power in -

Ground

Power in +

Signal in

Sol B -

Sol B +Sol

A +

Sol

A -

EVDR0201

3

Power in -

Ground

Power in +

Signal in

Sol B -

Sol B +Sol

A +

Sol

A -

EVDR0201

4

Power in -

Ground

Power in +

Signal in

Sol B -

Sol B +Sol

A +

Sol

A -

U/D 1

U/D 2

L/R 1

L/R 2

Joystick

control box

connector

12

Volt

Power

Supply

+

-

+

-

FUSE

Solid-State

Relay

Pump-Motor

Combination

Electronic Component Box

100 O Resistor

1 K O Resistor

100 µ F CapacitorSignal

Diodes

U/D 1

U/D 2

L/R 1

L/R 2

Joystick

control box

connector

+

-

12V inGround5v outLR+UD+GNDGND

Joystick 15 V Voltage

Regulator

L/RU/D

12V inGround5v outLR+UD+GNDGND

Joystick 25 V Voltage

Regulator

L/RU/D

Joystick Control Box

Both of these boxes can be prepared in a multitude of ways and both have room for

organizational improvement but the instructions below will outline the assembly process. As

long as the wiring ends up looking like that above the assembly will operate.


This is a picture of the joystick control box. Two small holes have been dremelled out of the top

of the box to allow movement of the joysticks. A Small LED power indicator has been mounted

to the top and linked directly to the incoming power and ground wires.

This is a picture of the inside of the joystick control box. All wires are soldered to a wire which

carries 8 connections out of the box.


Each Joystick is mounted to a small circuit board which is in turn mounted to the top of the

control box. Each joystick has a 5V Regulator which carries power to the joystick. Each joystick

has two power inlets and two ground inlets which can be bridged using a wire. Each Left/Right

and Up/Down signal is carried through a wire which is soldered to the larger bundle to carry

signal out of the box.

Organizational improvement of wire management can be used here especially regarding solder

placement on the circuit board.


This is the outside of the control box. It has two externally mounted LEDs, one for the overall

power of the box and another for the Pump-Motor power.

This is the inside of the control box. It has much room for improvement, the biggest

recommendation being it needs a larger box to organize all of the electronics. The box used in

this picture was cramped and although functional didn’t adequately house the components.


The basic idea of the control box was to power all of the EVDRs, ground all of the EVDRs,

collect the signal from all of the EVDRs to send activate a relay, and power the Pump Motor

when the relay is activated.

To power and ground everything in the control box a terminal strip was used.

The only connection that needs more detail and description would be the electronic relay circuit

which can be seen below.

Another terminal strip is used to collect all of the signals from both plugs of the EVDRs. A small

circuit board was made to attach diodes to the end of each of the signals as well as add the two

resistors and capacitor. A circuit board is the best route to connect all of these together. One wire

is led from this circuit board to the relay and another is led back to ground.


Final Assembly

Now it is time to move on to the final assembly of the system.

Initially you must first cut down the ¾” wood base to fit the top of your box. At this point you

can spray paint your wood to give it a waterproofing and aesthetic finish. You must then mount

the plywood to the box using bolts. Cinch this down so the top of the box now includes the wood

as part of it.


At this point you need to mount both the arm and the swing cylinder to the box.

The placement on the arm and swing mount can vary, but you need to allow for the swing

cylinder to turn the arm to the extent you prefer.

The mounting plate can be screwed in using wood screws.

There will be two bearings mounted to support the arm of the machine. One on top and the other

on bottom creating a support for the arm itself. To mount these 5 holes must be cut, four aligning

with the mounting holes on the bearings, and the last one to allow a bolt to pass through the

middle of the bearings. These will be mounted using bolts and nuts.


All of the cylinders can now be fitted with 90 degree fittings converting the pipe threading to

SAE size 4. To do this use standard pipe tape and snug the fittings until they reach your desired

angle.

Now you can mount your swing cylinder to the box using bolts and fastener nuts to make the

attachment on the arm and the height of the cylinder equal.


At this point the machine should now look like this:

All of your external components of the machine are now finished. It is now time to proceed to

the inside.


The hydraulic tank needs to be fitted with a vented cap, and the two others need to be converted

from a pipe fitting to SAE fitting. The return line needs to be size 6 fitting and the pump can be

fitted with size 8 fitting.

The pump itself needs to be fitted with two pipe fittings to SAE size 8 fittings and the suction

side of the pump can be directly connected to the tank, and rotated upward to fit into the box

nicely.


This is going to be the overall layout from the inside of the box. At this point you can start

inserting the tank with connected pump into the corner furthest away from the hydraulic arm. In

my project I used two 2x2’s to raise the tank and mounted it using industrial strength Velcro so

the system can be moved and tweaked still. The control box can be mounted in the corner next to

the tank vertically and the plug from the control box can be mounted to the outside of the box to

allow a disconnect from the joystick control box. The power supply is then mounted into the

opposing corner with a hole in the box placed so you can have the power cord externally. The

manifold can be placed on top and will rest on the bottom of the box secured by all of the hosing

that will be connected next, but so that you can open the box and troubleshoot without having to

redo the system. All of your wired connections from the control box can now be made, including

the signal from the EVDRs, the power source, and the power source for the pump-motor.

The next step is to hose the system and manifold. You must first step the port sizes for the hosing

down from size 6 to size 4 SAE. You can then begin hosing the system from the outside in. It can

be attached in any order but each valve must control both directions on the same cylinder.


The hose from the pump can now be connected to the manifold as well as the pump that will

return to the tank. These are all using size 6 SAE fittings.

Your final hosing should look like this:


The arm can now be operated, plug in the power supply and ensure the light is on your joystick

controller and you are good to manuever. Make sure all of your hoses and fittings are well

attached and make any additional changes on a case by case basis. Adding any pressure drops

significantly reduces the effectiveness of the system, and a filter should not be necessary in

closed environments.

The construction process can be done in many ways, and I’m sure I made mistakes as well.

There is much room for improvement, but after completing it I am very happy with this project. I

hope you had as much fun building this as I had designing it and I’d like to thank Purdue and the

CCEFP for the initial design.


Below you will find the buy list.

With Bolts I have included longer lengths than needed and I recommend cutting them down after

installation. Some numbers may be higher than necessary but buy as needed for the list.

Buy List

Part Where to buy Descriptio

n Amount Usage

1/4 Lock Nut Local 1/4"-20, Lock-

Nut 10 Used on all assembly

1 K O Resistor Electronic

Component 1 Component Box

1/4 Washers Local 1/4" ID 20

Used in attaching swing sylinder

mounting plates

100 O Resistor Local

Electronic Component 1 Component Box

100 μ F Capacitor Local

Electronic Component 1 Component Box

3/8 Lock Nut Local 3/8"-16 10

Mount the two bearings on the wooden board

3/8 Washers Local 3/8" ID 10 General Mounting

4 Sized Hose Local 2x24",30",34",40",46",2x56" 8 total Hosing to Cylinders

6 size Local Fit to length 2 total

Hoses from pump to manifold, from

manifold to tank

8-32 Lock Nut Local 8-32, Lock-Nut 6 Angled Brackets

Aluminum Box Structural

Tubing

http://www.mcmaster.com/#catalog/119/3630/=mnbc6h

1 Arm

Aluminum U Channel

http://www.mcmaster.com/#catalog/119/3635/=mnbbsm 1 Arm

Board Paint Local Black gloss

acrylic enamel 1 Asthetic

Boom & Claw Mounting

Bracket Bolt Local 1-1/2" L, 8-32 3 Bolts for brackets

Boom and Stick Cylinder Affiliated Control

H-094-DUZ (D-8309-A) x2 Cylinder

Boom, Base, Stick

Connecting Bolt Local

1-3/4”L, 3/8”-16 4 Bolts



http://www.mcmaster.com/#catalog/119/3635/=mnbbsm

http://www.mcmaster.com/#catalog/119/3635/=mnbbsm


Bucket Cylinder Affiliated Control

H-092-DUZ (D-8309-A) 1 Cylinder

Bucket Cylinder

Clevis Bolt Local 2" L, 1/4"-20 10 Bolts

Electronic Relay Crydom D1D20 Relay Switch 1 Pump-Motor Power

EVDR 0201 Hydraforce Electronic

Component 4 Valve Drivers

Fittings Local As needed

As neede

d Hydraulic Fittings

Flange Bearing

http://www.surpluscenter.com/item.asp?catname=hydraulic&qty=1&item

=1-201-8-4-C 2 For Swing

Flange Bearing Bolts Local

2-1/2" L , 3/8"-16 2 For Swing

Hydraulic Resovoir

http://www.easternmarine.com/moeller-4-gal-water-waste-holding-tank-

041204 1 Hydraulic Container

Industrial Strength Velcro Local Velcro Securing

Joystick http://www.allelectronics.com/make-

a-store/item/PX-27800/2-AXIS-THUMB-JOYSTICK/1.html 2 Controls

Manifold and Valving Hydraforce

Finished Manifold

Block 1 Hydraulic Manifold

Plastic Storage Box Local

27 gal, J Terence

Thompson Inc. 1 Container

Power Supply Local 13.8VDC 15A Power Supply 1

Pump and Motor

Combination

http://www.northerntool.com/shop/tools/product_200578544_20057854

4?isSearch=2682271 1 Pump motor

Rectangular Steel Tubing

http://www.mcmaster.com/#catalog/119/3666/=mnbcxv 1 Arm

Signal Diodes One way diodes 8

Collect signal from EVDR

Steel Plate Local 1 For Claw

Swing Cylinder Affiliated Control

H-174-DUZ-D-(8331-A) 1 Cylinder

Swing Cylinder

Mounting Local 2-1/2" L, 3/8"-

16 1 Bolts

http://www.surpluscenter.com/item.asp?catname=hydraulic&qty=1&item=1-201-8-4-C



http://www.easternmarine.com/moeller-4-gal-water-waste-holding-tank-041204



http://www.allelectronics.com/make-a-store/item/PX-27800/2-AXIS-THUMB-JOYSTICK/1.html



http://www.northerntool.com/shop/tools/product_200578544_200578544?isSearch=2682271



http://www.mcmaster.com/#catalog/119/3666/=mnbcxv

http://www.mcmaster.com/#catalog/119/3666/=mnbcxv

http://www.mcmaster.com/#catalog-holders/=mnxrj4


Bolt

Swing Cylinder

Mounting plate

http://www.mcmaster.com/#catalog/119/1534/=mnxnit

1 For Mounting

Swing Cylinder

Mounting Plate Bolts Local

1-1/2" L, 1/4"-20, Flat Head 1 Bolts

Teflon Tape Local 1/2" Wide 1 Seals

Wiring Local As needed

As neede

d Misc wiring

Wood Base Local

3/4" plywood, 2'X4', grade B

or higher 1 Base

Wood Screws Local Flathead #10 x

1 1/2"

As many

as neede

d Securing to board

Zip Ties Local

As many

as neede

d Misc



Documents

HydraForce PFPD assembly