- The Hook and Pull helps fixed seat adaptive rowers independently use erg rowing machines. After getting strapped into their seats in a fixed seated position, rowers can use this device to hook the erg handle from the cradle of the erg and pull it back to them in order to begin rowing. They can then use the other side of the hook and pull to press the buttons on the erg monitor. The rowers can use the Hook and Pull to return the handle back to the resting dock gently when they are finished using the erg machine.
- In order to create the Hook and Pull, we have created a DIY step by step process for machine-shop and at-home users. Both proccesses have the same end goal but machine shop users may have access to different machines than at-home users.
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Step 1: Ordering Materials
Although you can use substitutes materials when assembling the erg grabber, we recommend specific products for their ease of use and versatile functioning.
The most predominant aspect of the erg grabber is the blue rod, which is a modified hiking pole. We recommend the BAFX hiking pole because of its lightweight and durable nature, affordability and because we know its design works with this approach. It is worth noting that BAFX is You can order the rod here:
- BAFX Products® - 2 Pack - Anti Shock Hiking / Walking / Trekking Trail Poles - 1 Pair ($29.99)
You'll also need two aluminum rods 1/4 inch diameter and 12 inches long for the hook components of the grabber. These rods are light, durable, and bendable. To DIY, you can use anything from wired clothes hangers, to wire fence leftovers in the garage, although it's important the rods be lightweight, bendable with force, but srong enough to pull the erg handle. Here is one source for the rods that we used when designing the product:
Multipurpose 6061 Aluminum Rods: 1/4in diameter, 3 feet length ($4.99)
You will need to use an adhesive to connect the hooks to the rod. We recommend using a fast-hardening epoxy, or a similar adhesive. We have had success using epoxy because it is easy to mix, easy to pour on the rod, hardens quickly, and provides sufficient strength.
High Strength Epoxy - Single Packet ($1.60)
*PLEASE NOTE* When using epoxy it is imperative that you do not inhale the chemicals. If possible, wear masks, and use in a well-ventilated outdoor area. There are many sources of epoxy, but here is a link for reference.
There is a possibility that you will want to add a grip aid to your erg handle grabber. Although you can use other straps or fabric bands, we recommend using a velcro strap.
10 Assorted velcro straps ($1.35)
Finally, it is possible to create a knob on the bottom portion of the hiking pole that can be used to hit specific buttons on the erg monitor. Since the hiking pole has a built in compass at the bottom of the rod, we found it useful to simply glue an additional layer of velcro to the compass in order to create a knob. Although you could probably use a variety of adhesives, we recommend using a hot glue gun as it is quick, efficient, and cost-effective. We did not find epoxy to provide effective adhesion.
Here is a link for a cheap hot glue gun, cost: $3.99
Step 2: DIY: Machine Shop or at Home!
After ordering the hiking poles, epoxy, aluminum rods, and velcro straps you are ready to begin assembling your erg grabber!
We include steps specifically for machine shop and at-home users. Some steps for the machine shop and at-home users will be identical; there are, however, some steps that require different materials and tools. We will specify when there are conflicting instructions and provide the at-home users with alternative means to achieve similar ends.
Before you get started, please see the chart breakdown of the material cost, and the manufacture time for the poles, so that you have an idea of how long and expensive the process will be.
Step 3: Turning Your Hiking Pole to a Handle Rod
- Remove hiking pole from packaging
- Extend the hiking pole fully
- After extending the three sections, pull the top extension off of the hiking pole (you will not need the top part of the pole, and can dispose of it)
- After removing the top level, there should be 2 levels remaining on the hiking pole.
Step 4: Machine-Shop or DIY
If you have access to a machine shop, you will be able to create smooth and exact hooks.
The following instructions is for those of you who have access to machine shop tools and resources:
To start creating the hooks, cut the 1/4 inch diameter aluminum rods into two lengths of atleast 12 inches, using a saw such as a band saw.
- Find a cylinderical object to bend your metal around...we found that using a metal circle with a 3 inch diameter worked well.
- Clamp the cylindrical object to a vice, and secure the aluminum rod to the bottom of the circle using a small clamp(leave one inch of rod before the start of the bend.)
- Grab the other end of the aluminum and pull it toward you so that it bends over the circle that is clamped to the vice.
- Make sure the diameter of the bend you created in the hook is at least 3 inches wide, it doesn't need to be perfect!
To create an extra smooth hook and make sure the edges of the hook are not rough:
- Use the disc sander to file down the edges of the hooks
- Scrub the hooks with Scotch-brite to get rid of marker marks and make them shiny
Please note, if you do not have access to a machine shop, see the next step for at-home techniques that make bending the hooks possible.
Step 5: Hooks From Home!
- When creating the hooks for your erg handle grabber, you will need 2 rod-like objects.
- The two objects will need to be around 12 inches each. If the rods are longer, you can use a saw (most types found in garages will do) to cut the rods into 2 smaller rods of the length of 12 to 13 inches.
- Find a circular object that you can bend your metal around, such as the base of a flower vase, the arm of a sturdy chair, plumbing pipes, or gutters. You can even step on part of the rod to start the bend, but it is a good idea to find something circular to finish the bend.
- The bend should be around 3 inches in diameter
- We have included images of the various ways that you can create your bend
- These are just various suggestions; we recommend an aluminum rod in order to make the strongest product.
Please note that the depth of the hook (starting from the top of the bend) should not be more than 3 inches. If the end of the hook (the part of the hook you wrap around the erg handle) extends too much the hook will not be able to grab the handle, as there will not be enough space in between the handle and the monitor. While the width of the bend in the hook can vary in dimension and still work, if the hook is too long the grabbing process won't be possible. A helpful trick for ensuring the hook doesn't extend too far is to mark one inch on the end of the hook before bending. Please see pictures to double check that your hooks are the correct length and do not extend to far.
Step 6: Giving Your Hooks an Angle
At this point in the process, you have two hooks that are around 12 inches long, bent into curve that is at least 3 inches thick.
The erg handle requires the hooks to have a slight angle bend since the hooks need to reach and hook around the erg handle cradle.
This step requires you to secure the bottom of the hook in a vice and hammer 5 or 6 times from the base. Please see pictures for the angle and position of the hooks. The goal is to having each hook angled in a different direction. You will need to hammer from the right side for one hook and the left side for the other.
- For at-home users, it is important to create the bend, but it is up to you for how you want to accomplish that. We recommend using a hammer, since it is an effective way to create an angle on the rod. If you use a hammer, possibilities include securing the hammer on a table and hammering in a downward motion, completing the same action in the opposite direction for the second hook.
Step 7: Connecting Your Rods and Hooks! Scoring the Rod
At this point you should have 2 bent hooks and the hiking pole. The next step is to use epoxy to secure the hooks to the hiking pole. This step of scoring the inside of the hiking pole will be the same for both at-home and machine-shop users! If you have access to a file, that works well! Sandpaper is another good choice. You could also try a knife, fork, or any other sharp object!
The paint on the inside of the hiking pole needs to be scored for the epoxy to work. To begin, hold the hiking pole straight up, with the hole facing upwards. With a fork, scraper, knife, or any other sharp object, start scoring the inside of the pole. Scoring the inside of the hiking pole will allow the epoxy to have the most effective adhesion.
Step 8: Positioning the Hooks
Collect your hooks and use a rubber band, hair tie, or any string capable of tying the hooks together. Position the hooks so that there is around 4 inches in between the top of the curve. This step is identical for both at-home and machine-shop users.
Tie the base of the hooks together.
It will be helpful to have a ruler, scissors, epoxy packets, paper, and a popsicle stick out for the next stop.
Step 9: Connecting the Hooks to the Rod
This step is identical for both at-home and machine-shop users. After the inside of the pole is sufficiently scored and scratched, put your face mask on and stick the two hooks that are tied together with the rubber band into the top of the hiking pole. Double check after the hooks are stuffed in the rod that there is a 4 inch gap between the tops of the hooks, and that they are facing in the right direction as shown in the picture.
Open the epoxy pack (don't forget to do this in a well-ventilated area and/or with a mask!). With a popsicle stick, knife, or any piece of wood, stir the two components of the epoxy. When the epoxy changes from a clear to a white-colored substance, scoop up the epoxy and apply the epoxy to the top hole of the hiking pole where the hooks are situated. Fill the gap between the hooks and the hiking pole so that the white substance fills to the brim of the rod.
Keep the rod in an upward position! You can lean it up against a counter or chair, just make sure the hooks are not sliding up or down during the drying process.
Our epoxy packet recommends a 3-5 minute work time for applying and drying, but we waited 24 hours for erg grabber to dry, just in case!
Step 10: Grip Aids
Congratulations! You have officially constructed a erg handle grabber! We have found that adding additional grip aids to bottom side of the hiking pole can assist with pulling the erg handle back towards you when you are in a seated position.
If you find that the pole is sufficient as is, you do not need the grip aids and can skip step 13. If you want additional grip aids on the pole, follow these instructions.
You can use household velcro straps, and epoxy them to side of the handle as shown in the next step.
Step 11: Scoring the Rod for Grip Aids
This step is identical for both at-home and machine-shop users. Just like you did to the inside of the hiking pole, it is important to score the area that you will attach the grip aids to.
Use a file, knife, scraper, or fork, anything that can score metal surfaces.
See pictures for appropriate areas to score and attach grip aid to. We recommend using the writing on the hiking pole to measure the spot for scoring, however you should place the grip aids where it feels most comfortable for you during use of the erg grabber.
Step 12: Epoxy Grip Aids
This step is identical for both at-home and machine-shop users. After you scored the appropriate areas for gluing the straps to rod, bring out the face mask! You will use epoxy, so make sure you are in open, ventilated space.
Open the Epoxy packets, mix the 2 parts, and spread it on the rod where you have scored and/or velcro strap. Place the velcro scrap on the hiking pole. You can hold the strap in place or you can use tape to ensure that pressure remains on the grip aid while the grip aid is drying(we recommend using tape so that you don't have to keep your hand on the rod for a long time).
Let grip aids dry over night.
Step 13: Use the Bottom of the Hiking Pole to Press the Buttons on the Erg Monitor!
Once the rower has the erg handle they will still need to press the buttons on the erg monitor accurately to start their workout. We have made an extension on the bottom of the hiking pole to accomplish this.
- Cut 3 velcro scraps (you can use extra velcro you ordered) into 1/2 inch portions (the dimensions of the compass)
- Velcro the scraps together
- Cut the velcro into a circle
- Using a hot glue gun (or any other strong adhesive) to put glue on the compass and press the velcro scraps compass on the bottom of the hiking pole.
- Leave the velcro to dry on the hiking pole for a couple of hours.
- Awesome job! After the erg monitor button presser dries you are officially done assembling the erg handle grabber!
Step 14: Thank You!
Engineering 111, a seminar offered at Wellesley College and taught by Professor Amy Banzaert called Product Creation for All afforded us the unique opportunity to work with Community Rowing Inc. (CRI) (https://www.communityrowing.org/). CRI is a renowned rowing facility that offers rowers with mental or physical limitations the opportunity participate in the sport. After working on separate products last semester, we teamed up to create the Hook and Pull. Combining the best aspects of both of our designs allowed us to provide CRI with an even better product than we started with. We would like to thank Jenny Sichel and Priscilla Lowell for their constant support and assistance with the entire process. The feedback and constructive criticism they provided us helped guide us towards a final product that met more of the needs of the adaptive rowers.
If you would like to learn more about the Wellesley College Engineering lab (We-Lab), where ENGR 11 is taught, please visit http://www.wellesley.edu/engineering for more information!
-Celeste Glober and Jenna Mulrenan, Engineering students