Jar Closing Aid




Introduction: Jar Closing Aid

About: > Master Industrial Design, Ghent University

Jar Closing Aid is a DIY assistive tool to close jars without damaging the lid or the pot and without the need for high strength of the user. The aid is easy to reproduce, adapt and that can be made with everyday accessible tools and materials (wood, a silicone gun, screws, sawing machine, etc.)

Note that this aid works only for non-circular jars (square, hexagonal, etc.)

The assistive tool exists of 4 main parts, which are also shown in the pictures:
1. The Base Frame
2. The Silicone Gun System
3. The Handle
4. The Lasercut Jar-holder

In this instructable we describe how each of these parts can be made.


Jar Closing Aid was created at Ghent University - Campus Kortrijk, for the lesson Desigh For Everyone. The case was to design an assistive tool to close jars of eggnog. There are already a lot of assistive devices for the opening of jars, which can theoretically also be used for closing. The problem with this existing devices is that they damage the lid of the pot. In the context of sheltered workshops and the like, where these jars have to be sold afterwards, this is definitely not allowed.

Step 1: Tools & Components

This is a list of the materials and tools we used to make the Jar Closing Aid. Of course, there are a lot of other possibilities in tools, operations, connections, materials, ... so feel free to reproduce the aid in your own way.



- Sawing machines (or possibly a handsaw)
- Drilling machine
- Cutter
- Screwdriver or screwmachine
- Sandpaper or sanding machine
- Glue/Silicone Pistol
- 2 x Big Clamp (picture)
- Caliper Measuring Tool
- Pleat meter or tape measure
- Drill 4mm, 10mm, 22mm, 3.5mm,
- Milling machine (not necessary, can also be drilled)
- Laser cutter (can be used in fablabs)
- Universal Pliers or wrenches to disassemble the silicone pistol
- Socket Wrench for M8 nuts.


- 1x wooden beam : the beam we used measures 67mm x 43mm x 2700mm
- 3x angle profile 90°: width 4cm - length 20cm - 5mm thickness
- 1x multiplex/wooden plate for the baseplate : 33cm x 33cm x 5mm thickness
- 1x multiplex/wooden plate: 20cm x 20cm x 15mm thickness
- 1x box of long screws: we used 5,0x60 mm / 28pc (picture)
- 1x box of short screws: we used 5,0x30 mm / 54pc(picture)
- 1x silicone pistol with possibility to disassemble (picture)
- 1x plate that can be lasercutted (as jar-holder): 24.5cm x 24.5cm x 3mm thickness (will be lasercutted)
- 4x bolt-nut connection (size to preferably, but not too large... we used M3)
- 1x tube of PU wood & construction glue
- 1x tube of wood glue
- 1x sheet of grip material: silicone cellphone grip for cars (picture) OR other thicker silicone sheets like we used...


- 3x spray paint (if a color code is wanted)
- 1x car floormat with grooves (35cm x 70cm)

Step 2: Sawing the 4 Side Beams (1.1)

In this step the side beams (1.1) for the wooden base frame will be sawed out of the beam.


The base-frame is made out of pieces of the wooden beam (in our case 67mm x 43mm)
The pieces we used are dimensioned as in the sketch above.
The four Side Beams (1.1) we used have dimensions 330 x 43 x 67 mm and a 45° corner on both sides to join them afterwards. The sawing operation can be done with mainly every sawing tool.

How the parts fit together can be seen in the next steps or in the assembly picture.

Note that other dimensions are also possible, just make sure that the base is solid enough and fits in the end.
Also the 45° cut is not necessary, but we liked this connection in our aid because of aesthetic reasons...
Also, we used wood and varnished it afterwards to make it more washable... in some contexts a metal frame is more applicable. This base part can be adapted to the context and the users.

Step 3: Sawing the Reinforcements for the Frame (1.2)

In this step the reinforcements (1.2) for the wooden base frame will be sawed out of the beam.


To create a strong connection and make the assembly more easy, two reinforcements were added in our base-frame. In our case we made these reinforcements out of the same beam (67mm x 43mm), but lying flat as can be seen in the pictures. The twoReinforcements (1.2) have dimensions 245 x 67 x 43 mm, because they have to fit in the frame in the next steps. The sawing operation can be done with mainly every sawing tool.

Step 4: Sawing the Jar Supports (1.3 & 1.4)

In this step the Jar Supports (1.3 - 1.4) for the wooden base frame will be sawed out of the beam.


The Jar Supports are in our case two pieces made out of the same wooden beam as the previous parts. They have a smaller height than the reinforcements, because all jars should fit in the aid (the small jars and the big jars). If you look further in our instructable, it will be clear that the height of this support will have an influence on the height of the jar (which should be high enough for a good comfort). These two parts (1.3 and 1.4) have dimensions (1.3) 245 x 67 x 30mm and (1.4) 245 x 43 x 30 mm.

In our case the jar support is made of two beams, but note that it could also be one part or another material... We chose to make the support out of the same wooden beam, because in this way less material is wasted.

Step 5: Sawing the Vertical Beam (1.5)

In this step the Vertical Beam (1.5) for the frame will be sawed out of the beam.


This beam wil later be used to assemble the frame with all the angle profiles. The vertical beam (1.5) has dimensions (1.5) 330 x 67 x 43 mm. This one can again be sawed with any sawing tool that is available.

Step 6: Assembling the Wooden Frame (1.1 - 1.4)

We used a mittre-connection (45°), reinforced with two wooden beams, to keep the square frame together.
Also in this step, it's possible to use other connections to make the (in our case) square base-frame.
The mittre-connections (45°) were glued and clamped. The two reinforcing wooden beams keep the other pieces in the right position when clamped. We used a few screws to make the connection even stronger and to keep everything well-positioned.


As can be seen in the picture. The 4 Side Beams with the mittre connection (1.1) form the square of the base frame. These parts are glued together. To make the assembly more easy and solid, the two reinforcement beams (1.2) can be screwed between them (picture).

The two support beams (1.3) and (1.4) don't need glue or screws, they will fit in the frame when finished.
The Vertical Beam (1.5) will be needed later.

Step 7: Sawing the Baseplate (1.6)

Under the frame (made in Step 2&3), a baseplate should be attached that is sawed out of a multiplex plate.


We made a baseplate (1.6) made of multiplex with dimensions: 33cm x 33cm x 5mm thickness (shopping list).
If the purchased plate is bigger, it should be sawed at this dimensions first.
To saw this baseplate, different sawing tools can be used depending on the available tools and materials (we used a industrial panel saw).

Also the plate holds a cut-out (in which the angle profile 1.8 will fit): 4cm x 20cm (sketch)
This can be sawed again with different tools, but we recommend a belt saw.

We chose 5mm as thickness, because then the angle profile will fit perfectly in the gap (picture).
Note that if other angle profiles or other base-frame dimensions were chosen, the dimensions of this plate will differ.

Step 8: Securing the Baseplate (1.6)

Once the Baseplate is sawed, it can be attached to the bottom of the frame.


To attach this one, the short screws (5,0x30mm) were screwed along the periphery of the plate.

Step 9: Disassembling the Silicone Gun (2) & Measuring the Thread Insert (2.1)

Before the Angle Profiles can be adjusted, a dimension of the thread insert in the silicone pistol is needed.
The dimension of this part, used to mount the silicon pistol later, will determine the dimension of the hole that will be drilled in one of the next steps.


So first of all, the silicone gun (2) needs to be disassembled by loosening the nuts (the ones on the rod and the big one in the pistol). Afterwards, keep this parts momentarily safe because they will be re-assembled afterwards.

The thread insert (2.1) that was used to keep the parts of the pistol together, will be used to mount the silicone pistol with the frame. In order to drill the right hole in the Angle Profile in the next steps, the diameter of this part should be measured. In our case, the diameter was 23 mm, we think this is a rather standard dimension in this silicone pistols.

Step 10: [Optional] Painting Parts of the Silicone Pistol (2)

In our case, the users of our jar closing aid had some problems with reading, interpreting and remembering the steps to close the jar. That's why we decided to add a color-code to our assistive tool, which makes it more easy to remember the order of the steps (first yellow, then green, then red and yellow...).


Because the painting of this parts asks some time to dry and to finish, we painted them while assembling the frame. In this way, the time to make the product remains limited and the assembly will go smoothly in the next steps. Make sure that you use the right paint for the right materials.

Step 11: Adjusting the 90° Angle Profiles (1.8 & 1.9 & 1.10)

As mentioned in the shopping list in the beginning of this instructable,three 90° Angle Profiles are needed.
All of these profiles need a little adjustment to fulfill its function in the jar closing aid.

In the first Angle Profile (1.8):
- The holes need to be beveled a little bit, so the screws can sink a bit in the profile, to avoid sharp edges on which one could be hurt.

In the second Angle Profile (1.9):
- Again, the holes need to be beveled
- A hole should be drilled or milled with a diameter that fits threaded insert (2.1) of the silicone pistol (picture). The hole should be drilled in that way, that the thread insert can be centered above the frame (peek the next step).
- The thread insert of the silicone pistol can already be putted in the profile. Make sure that the thread is on the upper side (picture).

The third Angle Profile (1.10):

- Also, one side of the profile should be sawed so the leg is 5,5cm.
- Again, the holes need to be beveled, but on the other side because this one will be mounted in the inside of the aid (picture).

Step 12: Assembly of the Frame (1)

Now the base-frame (including the baseplate and the square frame) and the angle profiles are all ready, the frame can be assembled. This step is rather easy and happens by screwing the parts together, using the angle profiles.


The first angle profile (1.8) fits in the baseplate (1.6) and should be screwed to the beams (1.1 - 1.2) in the frame and the upright beam (1.5).

The second angle profile (1.9) needs to be connected also with the upright beam (1.5), so the thread insert (2.1) comes in the center above the frame.

The third angle profile (1.10) comes on the inside of the upright beam (1.5), attached to the reinforcement beam (1.2)

Check the pictures for the right positioning of the angle profiles...

Step 13: Sawing the Parts for the Handle (3.1 - 3.2) and the Support Triangles (1.7)

Now the frame is ready and while the parts of the silicon pistol are drying... the first steps of making the handle can be done.


The handle (3) is made of 3 layers:
- the upper layer (3.1) which contains the real handle and is made out of 15mm thickness multiplex
- the middle layer (3.2) in which the nuts are hidden, a square piece made out of 15mm thickness multiplex
- the bottom layer (3.3), existing of a material that creates a lot of friction/grip.

The first step to make this handle, is sawing the wooden upper layer, middle layer and 4 triangles.
To saw these parts, we used again a bet saw because of the ability to saw free forms.
The upper and the middle part have dimensions as in the sketches above.

Out of the restants of the multiplex plate of 15mm thickness, four triangles (1.7) should be cutted out (sketch).
This triangles will later sustain the jar holding plate in the frame.

All parts can be sanded for a better finishing.

When the user is weaker, the handle can be made longer or be customized for better comfort.
Also another shape or type of handle can be used. We used a standard, simple handle in our prototype.

Step 14: Drilling of the Holes in the Handle (3.1 & 3.2)

To attach the layers to each other and to attach them to the frame later on, some holes for bolts are needed.


Center of the handle (upper layer 3.1):
This layer needs a hole with a diameter of 10mm in the center, through which the silicone pistol will fit.

Center of the square (middle layer 3.2):
This layer needs a hole with a diameter of 20mm in the center, in which the nuts will be hidden.

Small holes through both layers (3.1 & 3.2):
After having drilled this hole, the two parts should be stacked so they fit perfectly. Now the small holes should be drilled through both layers, so the holes match perfectly. In this step, we used a 3,5mm drill (to use M3 bolts and nuts afterwards). The position of these holes can be chosen freely, but should be on the outside and evenly distributed (to keep the parts together well).

Drilling a sink for the bolts:
Afterwards, the holes can be drilled partly with a bigger drill, so the M3-bolts sink in it and the surface is flat.

Step 15: Rounding the Handle (3.1)

To make the handle more comfortable and ergonomic, the handle can be sawed till it fits your hand or the hand of the user... Other possibilities are adding textile or a soft material.

Step 16: Assembling the Wooden Parts of the Handle (3.1 & 3.2)

Once all the holes are drilled, the parts can easily be assembled.


We used M3 bolts and nuts to assemble it, so disassembly and replacing parts is possible.
Screws, glue or a bigger piece of wood with a hole in it are also possible solutions for making this handle.

We positioned the bolts and nuts in this way that the nut is on the upper side...
This makes assembly a bit easier and excludes damaging the lid of the jar while using the aid.

Step 17: [Optional] Personalize the Handle or Add Color Code (3.1)

If a color code is needed, the handle can also be painted or customized to make the aid easier to use.
The handle can be customized according to the will of the user.

Step 18: Creating and Attaching the Grip Layer (3.3)

Now the wooden part of the handle is finished and customized, the grip layer needs to be attached.


First of all, the grip material needs to be cutted big enough, so it fits the biggest jar.
We cutted a square-shaped part of 75mmx75mm, and attached it diagonally.
Note that we first used a cell-phone grip (black), but we saw that the thin ones fray through quickly.
So we recommend to search for a silicone layer that is thick enough, although the thin ones will work equally.

In order to keep the nut operable and reachable to tighten it when necessary, we made a hole in the grip material.
The hole was made by hitting a drill through the sheet of grip material (picture).

For the connection with the wooden middle layer afterwards, PU wood/construction glue was used (3.3).

Step 19: Assembly of the Silicone Pistol With the Frame (2)

Now all the parts are ready to assemble and finish...


The thread insert (2.1) (that was measured earlier and fits in the upper angle profile) should be positioned in the hole with the thread part pointing upwards. Now the rest of the silicone pistol can be mounted again (turning on the screw as before) but with the angle profile between the thread insert and the handle. All parts should be positioned as before, but the lower end of the rod should remain free, because this one will hold the handle later on.

Step 20: Adding the 4 Triangles to the Frame (1.7)

Some restants of the frame can be mounted now...


To sustain the jar-holders well and high enough, the 4 triangles created with the restants of the wood should be glued in the inner corners of the frame. Also beam (1.3) and (1.4) from the first steps can be placed in the frame definitively.

Step 21: Assembly of the Handle With the Silicone Pistol (2 & 3)

The finished handle should be mounted with the end of the silicone pistol.


The rod of the silicone pistol has a threaded lower end which is normally M8.
To create a strong conection with the rod, the handle will be clamped between three M8 nuts.

First, one single M8 nut should be turned onto the rod.
Then a ring should be pushed onto the rod so the upper side of the handle cannot be damaged.
Afterwards, the handle can be mounted on the rod and secured with two M8 nuts.

Make sure that all of the nuts are well tightened so the handle is well connected.
A socket spanner can be used to tighten the bolts hard enough.

Step 22: [Optional] Making and Attaching the Car Floor Mat

To fix the jar closing aid with a table in a releasable and easy way (without damaging, drilling, ... the table), we used this ribbed car floor mat. A sheet of this material will be attached to the aid with PU wood/construction glue and a sheet of this material will be attached to the table with twosided tape. The ribbed texture of both layers fit in eachother, so a strong connection between both parts is created. Note that this step is optional, other fixations are also possible.


First, the shape of the bottom plate of the aid is measured and cutted out (in that way that the texture is parallel with the upright beam). This sheet can afterwards be glued with PU wood/construction glue. When the glue has reacted and is dry, the sheet needs some finishing by sanding and cutting the filth away.

Step 23: Lasercut Jar Holders (4)

Now the aid is finished, the jar-holders can be lasercutted. Note that this aid works only for non-circular jars.


The attachments hold some examples of laser-files that we used in our case.

All you have to do is measure your jar and change the dimensions in the illustrator files.
A near fablab can help you making the files and lasercut them.

In the files, also limit stripes (90°) and an arrow were integrated to make it easier for our users.
The same aid can be used to open the jars, but the direction of the arrow should of course be changed.

The small gap is cutted out so the jar-holder fits over the inner angle profile.

Step 24: [Optional] the Finishing Touch

Now the aid is finished. Some finishing touches can be done to make the tool more durable or personalized...


To make sure that the tool is durable and used for a long time, the wood can be varnished or treated so it's washable. Also, before using it in a food- or kitchen environment, make sure that the aid is clean of dust and cuttings.

Step 25: How to Use the Jar Closing Aid

Step 1. Put the jar in the jarholder with the lid laying on the pot
Step 2. Make sure that the handle is in the start-position
Step 3. Let the handle fall down on the pot by pushing the yellow handle
Step 4. Press the black silicone gun once, so the force to close the pot is generated
Step 5. Now turn the handle from the one stripe to the second stripe (arrow)
Step 6. Lift up the handle again while pushing the yellow handle

Now the pot should be closed!
This aid is mainly useful in sheltered workshops and for people with certain limitations like upper limb impairments or people that have only one hand left... Hopefully this aid can help people and allow them to close or open jars again.

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    2 Discussions


    4 years ago

    Very nicely done!


    5 years ago on Introduction

    Very interesting solution to a unique problem.

    Your documentation is excellent, thank you for sharing this here!