I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Introduction

I have always been fascinated with weight training machine design. I had a bench press weight set at home that did not come with a butterfly attachment so I decided to build my own home gym equipment. It took me about 3 ½ years to complete because I do not have an Industrial Design, Woodworking, or Engineering background. With my system, a person can (1) perform both the butterfly and lat pulldown exercises transitioning between them with minimal effort and also have the ability to (2) utilize a workout standard where stacking columns of weight (instead of accumulating weight plates) in a moving grid generating even or uneven resistance, by organizing variety of pattern configurations (X,□, /,\, --, etc.), using cup shaped ballast inserts.

I decided to build with wood because I felt it was a more manageable material than metal: it would be an easier substance to cut, shape, and attach together. Constructing the frame, creation of the butterfly exerciser arms, fabrication of the weight box, creation of the lat pulldown bar holder, as well as any other appliances to be made and their connections would involve welding equipment and supplies. Dealing with wood, all I really worried about (besides wood stock) were basically bolts, nuts, and screws, Et al., concerning hardware and various saws, drills, and the like for tooling.

The following are a couple of evaluations concerning conventional stacked weight plate exercisers compared with my work.

Stacked weight plate machine evaluation #1

When increasing weight, an individual must either add whole plates (usually 10 pounds) or, if available, a half add-on plate (usually 5 pounds). If you want to use any weight level in between those values, it is often difficult to do so: both of these could hamper the use of progressive sets and foster overload dynamics.

My work Innovation #1

My system’s demonstration weight cartridges are ½ pound each (about 2 10/16 inches long and 1 14/16 inches in diameter): making them easy to manage. IF the inserts were made from solid steel roll stock their individual weight would be estimated at around 2 ¾ pound per item.

The smaller size increments have the potential to offer more options to those involved in progressive sets and likewise reduce the risk of overload during a circuit.

Stacked weight plate machine evaluation #2

Machines generally don't change their pattern, meaning you grab a handle, pull a cable, and then draw the stacked weight upward and downward. This can lead to repetitive stress on bones, joints, ligaments, tendons and muscles. Flexibility is also limited because equipment often concentrates on strengthening a limited number of muscle areas which leaves the surrounding and stabilizing muscles unchallenged (muscle fibers generally require new hurdles to improve).

My work Innovation #2

My system’s rate of repetitive stress is more controlled since the force needed to transfer weight is not universal. By changing the configuration of weights in the holder, targeting various muscle areas that need more or less attention (by adding or voiding pockets of stack inserts) accounts for this. In other words, the integrity of the exercise is not static because the individual can position the solid weight cylinders in organized horizontal/vertical patterns or treat them more as random free weights in the load basket.

Motivation

My efforts endorse: (1) how to apply simple machine principles (i.e. pulleys, leverage, and weight resistance) in developing a project, (2) promoting a positive message within the DIY universe (i.e. advancing individual knowledge, learning new skills, and the enormous feeling of satisfaction that comes from manufacturing your own things), (3) woodworking (i.e. which allows a person to be creative and is a wonderful medium for artistic expression) and, (4) inspiring others in the greater inventor community, all in a positive manner.

Tools used for the project:

●Hole Saw (3/4”)

●Cordless Drill

●Jig Saw

●Band Saw

●Circular Saw

Materials used for the project:

●Spade Drill Bit (7/8“)

●3/8” Drill Bit

●Machine Bolt (1/4”, 5/8”, 3/8”)

●Wood Glue

●Machine Screws (#6, #8, #10)

●Carriage Bolts (1/4”)

●Cloth Straps (1 foot long strips that were 1 ¾ inches wide)

●Metal L shaped angle brackets

●Wood screws (1“, 1 ½”)

●2 X 4 Wood Pieces

●Plywood (1/2 of an inch thick)

●2” x 2” Furring Strips

●Pulleys (3/4” Single Sheave Swivel Eye)

●Hose Clamps (1/2 – 29/32)

●PVC Pipe (1 ½”, ½”)

●Cotter Pins ( 3/32 X 1”)

●Wood Dowel (3/8”, 1 1/8”)

●Tape Measure

●Cardboard Tubes (3 inches across and 11 inches in length)

●Furniture Movers (4 in total, 3 ½ of an inch long, 10/16 of an inch wide, and a height of ¼ inch)

●Cardboard Squares (4 inches long and 3 6/16 inches wide)

●Plastic Squares (4 inches long and 3 6/16 inches wide)

●Quick Dry Cement

●Orange Duct Tape

●Electrical Tape

●Nylon Para cord

●Eye Bolt (1/4”, 3/8”)

●Screw Eye (1/4”)

●Plastic washers (2”)

●Fastener

Step 1: Exerciser Frame

I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Frame (All plywood material used here was ½ inch thick)

General

I used circular, jig, table, and band saws to help cut the pieces for this section. 1” wood screws, carriage bolts (1/4”), various sized machine bolts (1/4”, 3/8”), and machine screws (#6, #10) were largely used to connect various parts of the frame together. The entire unit is about 73 inches tall and about 41 inches deep with its width determined by the exercise the user is doing. For the lat pulldown bar exercise the width of the machine is about 49 inches. With the butterfly arm exercise the width of the machine becomes about 58 inches.

Structure

There are 2 wood center bars located just above the weight box. These are pieces of 2” x 2” furring strips held in place with ¼” carriage bolts which are 3 ½ inches long. The two upside down “U” shaped center supports, which can be detached from the base, are each 31 inches tall as well as 37 inches long across. There are attached on the sides with more ¼” carriage bolts (2 inches long) as well as a 3/8” machine bolt about 3 ½ inches long.

The 2 supports in the back of the unit are plywood planks which are 2 inches wide and 34 inches long. It links the top of the unit to its bottom portion. ¼“ machine bolts (2 inches long) were used on the bottom and a metal L shaped angle bracket (6”) along with wood screws (1”) connecting to those on top. The large 6” angle bracket was attached with (5) ¼” machine bolts that were 2 inches in length.

There are 4 pieces of 2 X 4 which are 31 inches in length each that make up the bottom corners of support for the frame. The 4 diagonal support legs around it are each about 19 ½ inches long and attached to it with 1” wood screws..

The two bottom framing pieces on the front and the back of the unit are 2 inches wide and 33 inches each in length. The two wood brackets near the bottom sides of the exerciser are each about 11 ¾ inches long by ¾ inches wide and their bottom edge was 7 1/2 inches from the floor. These are all fastened together with 1“ wood screws.

Rails

The rails that the weight box glides on are each about 44 inches tall, 2 inches wide and were held in place with 2 #10 machine screws each 2 ¾” in length. The inner track had side bumpers which were ½” wide each with an interior guide space that was 1 inch in measure. The two top support bars that connect the 2 sets of weight box rails, on the side, are 9 inches long, ¾ inches wide, and about ½ of an inch thick and are fastened using #6 machine screws (about 3 inches long with several washers) . The space between the rails in the front and the back was about 25 ½ inches. The space between the rails on the sides was about 6 ¾ inches. The rails were located on the frame 3 ½ inches inward on the front and the back of the outfit.

Another significant detail was figuring out how to make the weight box rise and fall on the movement track while minimizing the friction between itself and the rail surface. I researched various ways of how to make the friction between the connectors on the weight box and the conduit surfaces it to a minimum. I considered using various sprays, waxes, greases, lacquers, covers, wheels, and ball bearings to accomplish that. I ended up sanding the inside of the track extensively and then mounted furniture mover inserts (3 ½ of an inch long, 10/16 of an inch wide, and ¼ inch in height) to the weight box bracket sides for a successful connection.

I really had to get used to “balancing” the weight box when doing repetitions, equal force must be applied on both sides of this simultaneously in order to ensure a smooth glide up and down on the vertical track. If uneven pressure is applied on the up motion or relaxed on the down movement, the box may get stuck in position somewhere on its surface.

A clip setup helped to connect the para cord line from the weight box to both the butterfly exerciser and the lat pulldown bar. I added a fastener, tightened with a couple of cotter pins, to help keep that item taut in the clip arrangement.

Step 2: Exerciser Pulldown Bar Station & Butterfly Arm Support Blades

I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Pulldown Bar Station & Butterfly Arm Support Blades (All plywood material used here was ½ inch thick)

1” and 1 ½” wood screws and various sizes of machine bolts (1/4” & 5/8”) were some of the elements used to connect many things together in this section.

I had to determine the height of the lat pulldown bar from the floor. It had to be high enough to be out of the way of the butterfly arms but not so high that it was out of reach for a user to grab it from a sitting position. First, I mimicked the exerciser movement to determine how high from the floor to have the bar while I sat in a chair with full arm extension. I then knotted a string to the pulldown bar and measured the distance from the start of it to its end on the floor, which turned out to be about 65 inches in height.

The pulldown bar box (that supported the lat pull down bar holder and butterfly arm support blades) was about 11 inches tall, about 14 inches long, and about 7 inches wide. It’s mounted to a plywood base that’s 15 inches long by 10 ½ inches wide. 4 ¼” bolts 3 ½ inches long secure it to the frame near its front and back with the aid of additional wood screws (1”) and metal L shaped angle brackets (1 ½”).

2 pulleys (3/4” Single Sheave Swivel Eye) for the pull down exercise were mounted on wood blocks (2” x 2” furring strips that were 2 ¼ inches long) positioned about 7 ½ inches in front of the pulldown box which were then in turn mounted to a plywood platform (see the upside down “T” diagram that has no header) with ¼ bolts that were 2 inches long.

The holder for the pulldown bar was about 6 ½ inches wide, 8 ¼ inches long, and 2 ½ inches tall. That assembly was arranged with smaller pieces of wood sewn together by nesting 1” wood screws:

4 pieces were, 6 ½ inches long, 1 ½ inches wide, ½ of an inch thick

1 piece was, 4 ½ inches long, 1 ½ inches wide, ½ of an inch thick

6 pieces were, 8 ½ inches long, 2 inches wide, ¾ of an inch thick

There is a release system (utilizing a 3” eye and hook process along with a 4 inch hinge) that does free up the lat pulldown bar as needed (which itself was a 1 1/8” Poplar wood dowel that was 48 inches long).

A wood hold down arrangement, on either side of the back, of the unit works along with a large bolt (5/8”and about 4 ½ inches long) with corresponding washers (5 of them) in order to keep the butterfly support blades in place without shifting their position during the exerciser’s operation. The hold down bracket was an oddly shaped object (see diagram A) which was mounted to the frame with metal L shaped angle brackets (1 ½”) and wood screws (1”). The wood blades are each 33 inches long and actually made up of 3 pieces of wood (for a total height of 1 ½” inches s tall joined together with 1” wood screws . There were a series of connectors (2, ¼” screw eyes, 1, 3/8” eye bolt, and 2, 2“ inch metal L brackets) attached to, and by, the blades that were then connected to several bungee cords used to suspend the butterfly arms on the mid air track system.

2 other pulleys (3/4” Single Sheave Swivel Eye) were mounted just below the pulldown bar box on the frame; they were measured 12 inches in from the right and left edge. A nylon para cord (75 inches long) was used to connect the lat pulldown bar to the weight box.

Note: the values of the measurements in diagram A and the upside down “T” diagram (with no header) are all in inches.

Step 3: Exerciser Butterfly Arms

I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Butterfly Arms (All plywood material used was 1/2 inch thick)

1” wood screws as well as various sizes of machine bolts (1/4”), cotter pins (3/32 x 1”), and plastic washers (2”), and machine screws (#8) were some of the elements used to connect many things together in this section.

I determined the length of the butterfly arms by mimicking the exercises movement and motion. Next, I manipulated a flexible tube and made a “C” type shape in order to determine the appropriate distance forward necessary from the main unit’s frame. Finally, I marked and measured the appropriate distance when I laid it out straight: which came out to be around 44 inches long.

I also had to figure out how to do a circular arc turn using blocks of wood (2” x 2” furring strips). I overcame this by creating a jackknife motion, involving those connected together with linkage joints made from PVC pipe.

The butterfly arms (actually three separate blocks of wood) were attached together with the use of a ½ inch PVC tube 7 ½ inches long (a 7/8 spade bit was used to drill the holes for that activity on either side of each of the links) with cotter pins (3/32 X 1”) in coordination with plastic washers (2”) were used as well as a couple of hose clamps (1/2 – 29/32). The block closest to the machine was about 13 ½ inches long, the mid block was still about 13 ½ inches in length, and the block furthest from the exerciser was 15 ½ inches long in measure.

5 wood planks on each butterfly arm held the 2 x 2 inch furring strip blocks together. They were mounted with ¼” carriage bolts that were 3 inches long. Moving from closest to the machine and migrating forward, here are the board measurements:

Board #1: 1 ½ inches wide, 21 ½ inches long

Board #2: 2 inches wide, 24 inches long

Board #3: 2 inches wide, 24 inches long

Board #4: 2 inches wide, 21 ½ inches long

Board #5: 2 inches wide, 21 ½ inches long

Each of the arm paddles of the butterfly arms compilation were blocks of wood that were 2 ½ inches wide, 18 inches long and 1 ½ inches in height. Two pieces of ½” PVC tube piping, 6 inches long, also attached with help from cotter pins (3/32 X 1”) and plastic washers (2”) connected them to the housing, on both ends that allowed them to swivel while in use. A #8 machine screw (2 ¾ inches long) held the PVC pipe segment that protruded from both ends of the arm paddles. Three ¼” eye screws were used to complete the para cord circuit from the weight box and this piece of equipment. There were three adjustable fabric straps, 1 ¾ inches wide, located on the arm paddles for the user to make as loose or tight as deemed fit. In addition, a strap on top of the butterfly arm helped the user lift it off and put it back on the frame when needed.

There were 5 bungee cords on the butterfly arms attached to a series of eye bolts (3/8” & ¼”) on the bottom of the butterfly arm support blades that allowed it to glide forward in mid air and recoil back into starting position when done.

The butterfly arms used many pulleys (3/4” Single Sheave Swivel Eye) to work its operations.

2 pulleys on either side of the exerciser were attached to wood blocks (2” x 2” furring strips that were 3 ½ inches and 6 ¼ inches long respectively) who were themselves attached to the frame with ¼” machine bolts about 3 inches in length. The pulleys were also attached to the blocks of wood with 1/4" machine bolts that were 2 1/2 inches long and were located on the outside edges of those pieces.

I made a wood stop for the butterfly arms attached on either side of the frame that was 10 inches long and 1 ½ inches wide. It had three wood prongs on it with the front and the back being 2 ¼ long and 1 ¼ wide. The middle one was 4 inches long and 1 ½ inches wide (raised up 1 ½ inches high) all held together with 1” wood screws.

2 other pulleys were mounted just below the pull down bar box on the frame; they were measured about 12 inches in from the right and left edge. A nylon para cord (about 112 inches long) was used to connect the butterfly arms to the weight box.

3/8” dowel pegs (1/2 of an inch long) kept the butterfly arms locked in position when not in use along with a bungee chord attached to the exerciser frame with a 1" wood screw.

Step 4: Exerciser Weight Box

I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Weight Box (All plywood material used here was 1/2 inch thick)

1” and 1 ½” wood screws including of machine screws (#10), and machine bolts (1/4”), were some of the elements used to connect many things together in this section.

The weight box is 6 cardboard tubes (about 3 inches across, about 11 inches long, and 10/16 thick) joined together with 4 pieces of flat cardboard (about 10 inches long and 6 ½ inches wide) mounted to them (2 in the front and 2 in the back) with wood glue. The weight carriage has overall dimensions of about 14 ½ inches wide, about 24 inches long, and about 4 ½ inches high. There are 7 view ports on each tube (the holes drilled into the weight box were done with a ¾” hole saw by freehand and not on a drill press) so a viewer can tell how full each weight each tube was during a given time. The edges of those were spaced about ¾ of an inch apart and were visually centered on each of the drop cylinders.

I had to figure out how to represent weight in the exercise system without using flat plates, while being confined in a small amount of space (without compromising adaptability and/or portability). I overcame this by representing weight as “cups” of mass. I ended up taking a 1 ½” tube of PVC pipe and cut it length wise about 2 10/16 inches. I then used a 2” hole saw to cut a circle out of plastic and then glued and taped it to the bottom of the tube in order to get the cup shape I desired. After I secured the cup bottom, I filled it with quick dry cement and then covered it in orange duct tape in order to achieve a bright color so a user could see a noticeable change in the view ports as the insert dropped through the weight box. My exerciser uses a container (it itself weighs about 25 lbs.) that can hold up to 24 cylinder inserts (instead of using weight plates) to change the amount of force a user exerts for each movement. Wood pegs about 4 ¼ inches long are used to suspend the cup weights in individual positions in the tubes themselves. When not in use, weights can be placed in the grid container for compact storage.

There are two flap covers, they are 2 ¼ inches were 7 ¾ inches long (held together with 3 inch hinges using ½” machine screws) on either side on top of the weight box used to help keep weight inserts in the assembly as it was being used. They stay open or closed as needed when the bungee cords are connected to its central housing 2 ½ wide, 12 inches wide, and 2 ½ inches high.

There is an extension that sticks out of the outer edge of the flaps about 2 ½ inches further than the main part itself (it’s also about ¼ wide): the entire length of this piece was 5 inches. They stay open or closed as needed when the bungee chords are connected to its central housing 2 ½ wide, 12 inches wide, and 2 ½ inches high.

The top of the weight box (where the two anchor clasps connect to ¼” eye bolts which enable the weight box to rise and fall evenly) is a plywood section 2 ½ inches wide and 26 inches long. It’s connected to its center support column by (8) 1” wood screws. It’s also notched in the front of it to allow the flap extension to pivot back and forth with ease: this is 9 2/16 inches from center and up by ½ of an inch on both sides.

The brackets that attach the weight box and allow it to glide on the exerciser’s 4 rails were secured to it by 1 ½ inch long #10 machine screws (on the tubes themselves are inserts that those attached to) were 7 ¼ long by 6 ½ inches wide. A center piece of wood (6 1/4 inches long, 1 ¼ inches wide, and 3/4 of an inch in height) on it adds for stability and small furniture movers, 3 ½ of an inch long, 10/16 of an inch wide, and a height of ¼ inch, (on either side of the fixture) ride on the rail grooves to help hold it in place as it moves up and down.

On the bottom of each tube were cardboard slots which held thin pieces of cardboard or plastic (4 inches long by 3 ½ inches wide) that insured no weights would go all the way through the tubes unexpectedly.

A couple of wood strips that were attached to the top of the weight box and controlled by the vertical stops (on the frame) were 2 inches wide and 8 inches long (held in position by (7) 1” wood screws on either side).

The weight box is suspended 1 foot off the ground in its resting position and about 6 ½ inches from the top edge of the draw box. 4 bracket assemblies used 3 inch straight and metal L shaped pieces (1 ½”) using wood screws (1 ½ inch) and machine bolts (1/4” and ¾ inches long) to support pieces of wood which were 2 ½ inches long and 1 ¼ inches wide..

On the back of the weight box are 2 crossbars of wood (13 inches long and 1 inch wide) which added additional stability to it as it traveled up and down during operation. Support wood from the primary one were about 6 inches long and 1 inch wide. 2 other pieces of wood in the back of the unit (10 inches long and 2 inches wide) also provided support here. The top of the weight box, in the back, was connected to its center column by the way of the bars of wood held together with 1" wood screws.

Angle cardboard (3 ¾ inches in length) was fastened with wood glue to either side of each of the weight box tubes. These helped to keep the slot weight stops in place.

Fabric straps on top of the weight box allow a user to take it out and place it back again on the rail system for use.

The overall design, of this section, was based on a loose interpretation of the Connect 4 game.

Step 5: Exerciser Draw Box

I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Draw Box

The draw box is 31 inches long, 8 ½ inches wide, 6 inches tall, and has a bottom to it. The wood is ¾ inch thick and I used 1 ¼” wood screws were used to secure it together. It’s simply a way of collecting weight inserts as they empty out of the weight box in a more controlled manner.

Step 6: Exerciser Counter Weight

I was able to get a steady provision of scrap (or reclaimed) wood material provided by a local source (i.e. a company) nearby. This supply source enabled me greatly in constructing my project.

Counter weight container

A counter weight located in the back of the unit was a container I created which used wood 1 inch thick, 15 ¼ wide, 32 ¾ inches long, and 5 inches high. It holds a 50 lb bag of tube sand in order to stabilize the load being worked with in the front of the exerciser. It rests on the back of the support legs of the exerciser and is attached to it with large hooks. It is elevated off the ground between 11 and 15 inches diagonally as a result of my design.

Introduction: Concept Exerciser Prototype

Step 1: Exerciser Frame

Step 2: Exerciser Pulldown Bar Station & Butterfly Arm Support Blades

Step 3: Exerciser Butterfly Arms

Step 4: Exerciser Weight Box

Step 5: Exerciser Draw Box

Step 6: Exerciser Counter Weight