Post #913: A D-I-Y floor-to-chair aid for paraplegic wheelchair users

Posted on December 11, 2020

This post is now superseded by Post #927.  Ignore the post below, and look at #927 for the final plans for this device.

This design works, but it’s really a proof-of-concept.   I’m now looking for easier ways to build it.  As I figure out improvements, I’ll post them separately, and link to them here.

For example, today (12/12/2020) I tested whether or not the lower cartons need to be reinforced.  They don’t.  The empty cartons themselves are sufficient.  That alone shows that there are faster, cheaper ways to build these steps.

See Post #914 for proposed modifications and a somewhat easier way to do this.  I’ll post a revised set of directions when I rebuild this tomorrow.

Post #917 now gives the final changes.  As it turns out, the only set that’s feasible to build and use, using off-the-shelf materials, is set with 4.5″ riser height and four steps.  I’ll document building that set when the materials arrive later this week.

Original post follows.

 

This post is a set of instructions for creating a broad, shallow, portable staircase.  The idea is that a paraplegic wheelchair user could use this staircase,  along with a set of pushup bars, to move from floor to chair level or vice-versa.

That’s a picture of my wife sitting on the finished steps, left.  It’s meant to illustrate how sturdy these steps feel, as she is perfectly comfortable sitting on them.

This is a followup to Post #886: A floor-to-chair/chair-to-floor aid for wheelchair users.  If you want the background on why I’m doing this, and what this is for, read that post.

 

I’ll call these Shelley’s steps, after Shelley Ebert, the motivation behind this.  She’s a wheelchair-using friend who had the key insight that made these possible: For many wheelchair users, expensive (and sometimes unobtainable) floor-to-chair aids could be replaced by a set of shallow steps plus pushup bars.  She’s using the original version of these (Post #886), and suggested that I create a practical, simple, D-I-Y version.

You can make this set of steps on your kitchen table, using simple hand tools.  That’s the point of this.  The goal is to make a functional floor-to-chair aid using only hand tools, easily-available materials, and a modest amount of labor.

The design could not be simpler.  This staircase is 12 identical corrugated cardboard boxes, reinforced, stacked, taped together, and topped with sheets of  a durable, slick material.  I won’t claim that this is the best, cheapest, or easiest possible design.  But it works, and it’s feasible for just about anyone to build.

This staircase has fairly tall steps, which may not be ideal for some users.  The nearly 7″ rise of each step is only slightly smaller than a standard staircase.  That may make this version difficult or impossible for some users.

Modified directions for a four-step version of this, with roughly 4.5″ riser height, are given at the end of this post.  Due due to the larger number of boxes, the four-step version costs a few dollars more and takes about two hours longer to assemble   But the four-step, 4.5″ riser version might be a better choice for some users.

Total materials cost is about $45.  Add another $10 for a set of push-up bars.  Total assembly time is about four hours.

Don’t be put off by the use of corrugated cardboard.  These are solid when they are finished.  I weigh about 275 pounds.  There’s no flex at all when I sit on them, and only minimal flex when I bounce up and down on them.  I don’t know how long these will last, in use.  And I won’t know until I can find a beta tester for them.  But they are certainly sturdy enough for their intended purpose.

Physical dimensions: 

  • Three steps.
  • Rise between steps is just under 7″.
  • Total height 20″.
  • Total weight 21 pounds.
  • Each step surface is 12″ deep by 32″ wide.

Materials and tools

Above:  Materials and tools.  This is the general idea.  I’m missing the second roll of tape and the C-clamps, and I’ve included a scrap corrugated box (left) that I didn’t need.  But it’s basically a pack of 25 cartons (right), two hardboard sheets (behind), a piece of twine (green), and tape and hand tools (foreground).

Materials list:

(Please note that hardboard (with-an-h) is a different material entirely from corrugated cardboard.)

Tools list:

  • A utility knife and spare blades.
  • Large cutting board, plywood scrap, or other surface you can cut on.
  • A long straightedge (metal is strongly preferred, 3-foot or longer preferred).
  • Two small (e.g., 2-inch) C-clamps.
  • Tape measure.
  • Sharpie or pencil.

Some notes on tape.   I recommend using high-quality carton-sealing tape, such as 3M Scotch heavy-duty shipping tape.  But:

  1. Plan on using at least 45 yards of tape.  I managed to do this with one roll of tape, but just barely. To be safe, get two 50-yard rolls.  Or so.  I’ve factored in the cost of a two-roll pack above.
  2. It’s a help, but not totally necessary, if you have some sort of “tape gun” for applying the tape.  I used the cheap device that comes with the two-pack of 3M tape referenced in the materials list.
  3. Once I finished these, I realized that the 3M tape “crackles” a little bit as I sit on the steps.  I have not tested duct tape in this use, but you might want to do the assembly with a high-quality duct tape instead, to avoid that noise.
  4. The clear tape is unsightly.  I have not tested duct tape in this use, but that’s a reason to consider assembling this with decorative duct tape instead of clear shipping tape.

These steps have a utilitarian look, and I don’t include decoration in these instructions.  If you choose to cover the cardboard with something more decorative, you’d have to factor in time and materials costs for that as well.

I’ll talk about some possible variations in a separate post.  The only thing I will mention here is that cat owners may want to cut some of the leftover hardboard for corner guards, to avoid turning this into a scratching post.

By the time you are done, you will be very tired of cutting cardboard, and even more tired of find the @#$)#( end of the clear tape that has stuck itself back onto the roll.

Detailed Instructions

Overview:  You’ll take half the cardboard boxes and cut them into 6″ tall strips.  You’ll then pack those strips into the other half of the boxes, folding them so that they will all stand upright (and so, bear weight well).  You’ll cut three stair treads out of the hardboard sheets.  Finally, tape all that together to form the staircase.

Roughly speaking, each step of the assembly takes about an hour, more-or-less, for a total assembly time of about four hours.

Step 1:  Cut 12 boxes into 6″ strips.

Time:  One hour and five minutes.

Description:  Take 12 boxes and cut them up.  This step produces cardboard pieces to be used as internal reinforcements for the remaining boxes.  All the pieces will be exactly 6″ tall (or as close as you can make it).  Some pieces will be 16″ long, some will be 12″ long.  Keep those in two separate piles.

Main tip:  Go easy.  Cutting up this much cardboard takes a lot of effort.  Take two or more passes on each cut, rather than try to cut multiple layers of cardboard in a single pass.  Make the first pass with light pressure, and focus on accuracy.  Stay tight against the straightedge and keep the straightedge still.  Make the second pass with heavier pressure, and focus on getting the knife blade all the way down to the cutting surface below.   This method is not just easier, it’s actually faster than trying to do it in one pass.  If you try to cut multiple layers of corrugated in one pass, you inevitably leave a few little sections of cardboard un-cut.  Fussing with those individual un-cut sections takes longer then just taking a second pass down the entire cut.

Second tip:  Sharp blades matter. Cutting cardboard quickly dulls a knife edge.  Change your utility knife blade frequently. 

1.1  Pull 12 boxes out of the package.  Set the other 13 aside.

1.2  Cut the flaps off the boxes.

Above:  Flaps creased, straightedge in position, ready to cut.

Explanation:  Because the boxes are exactly twice as wide as they are tall, the flaps are the exact right size to be used as internal reinforcements for the remaining boxes.  So you cut the flaps off exactly where they join the box body.

  • Place one box flat on the cutting surface.
  • Bend the flaps up, just a bit, just enough to crease them so that you can see the exact line where the flaps join the body of the box.
  • Place the metal straightedge on this line and cut off the flaps exactly where they join the body of the box.
  • Put the short flaps and long flaps in separate piles.
  • See Main Tip above for best technique.

1.3  Cut up the bodies of the boxes.

Above:  Showing that the box bodies are too tall and too long.

Explanation:  The box bodies are slightly too large to be used as internal reinforcements for the other boxes.  You need to trim 1/2″ off them in each dimension, then cut the sides of the box apart.

  • Place one flap-less box flat on the cutting surface.
  • Measure and mark 1/2 in from the top edge of the box.
  • Place the straightedge on those marks and slice off that half-inch.
  • Use that as a template for slicing a half-inch off the rest of the box bodies.
  • Cut a small slice off each end if each box body, roughly 1/8″.  It’s faster to do this freehand, without the straightedge.  It doesn’t need to be precise, and corrugations will guide the knife fairly straight anyway.
  • Separate the two pieces of the box.  Bend each piece slightly to put a crease where the end of each side is.
  • Put one piece of the box body flat on the cutting surface and cut the two sides apart at the crease.
  • Repeat with the other piece of the box body.
  • Add the resulting long (16″) and short (12″) pieces to the two separate piles.

1.4  Sort the strips by height.

Above:  Before sort and after sort.

Explanation:  You will inevitably have some variation in the height of these strips.  They are really 6″ give-or-take, not 6″ exact.  You will get better support of the weight if all the strips in a given box (below) are the same height.  So take a couple of minutes to sort these by height, from smallest to largest.

  • Neatly arrange the 16″ strips upright on a table top (so that they are standing up 6″).  Use a heavy mug, book, or similar object to keep them upright.
  • Shuffle the strips around until they are roughly lined by from shortest to tallest.
  • Turn that sorted row of strips upright, to form a stack with the shortest strips at the top.
  • Repeat with the 12″ strips.
  • You now have a stack of long strips, a stack of short strips, and both stacks are sorted from shortest to tallest.
  • You needn’t get this perfect, just close.

Step 2:  Assemble, fill, and seal 12 boxes.

Time:  1 hour 15 minutes.

Description:  You are now going to fill 12 boxes with those cardboard strips, with the strips bent in a way that will keep them vertical.  Then tape the tops of the boxes shut. That way, all of that cardboard supports the weight of anything resting above it.

Note:  In my original build, I used scrap cardboard to make 24 3.5″ x 11.5″  “filler strips”.  I used these to fill the gap that occurs between the side flaps, as you assemble and seal the cartons.  That’s a good idea, but I think that’s not necessary, given how solid these turned out.  So I skipped that step in these instructions, but you will see those filler strips in the pictures.

Main tip:  Do whatever it takes to “square up” these boxes as you tape them.  Pound on them, beat on them, push them around.  Try to make the flap ends perfectly flush with the box sides.  Try to make the edges of the top and bottom flaps perfectly flush and aligned.  You will benefit from that when you go to final assembly.

2.1  Pull 12 boxes out of the remaining stack.  So, one box is left over.

2.2  Make up 12 boxes by taping the bottom flaps shut.

2.3  Fill ten (10) boxes and seal them.  Hold the last two boxes for the “handles” step below.

Above:  A stack of six “V”s after they’ve accordioned out (left), and with the short center pieces inserted (right).

Explanation: You want these inserts to stand firmly on their ends.  One way to do that is to inter-lock them into a rectangular grid, but that takes a lot of time and a lot of cutting so that the pieces will interlock.  By contrast, the method below simply folds the long inserts into a “V” so that they stand up, and uses the short inserts to keep those “V”s neatly pressed against the box walls.  The upshot is that you get “grid” that is plenty strong enough, with no additional cutting.

  • Take six “long” pieces (16″ pieces) from the pile created in Step 1.
  • Fold that stack neatly, at roughly the 8″ mark.  Just enough to crease the pieces.
  • Take each piece separately and fold in half at the crease.
  • Re-stack those pieces so that the folded ends alternate.  (I.e., flip the first, third, and fifth pieces end-for-end.
  • Place this stack of pieces into the box and let it “accordion out” to fill the box.
  • You will now have six “V” of cardboard, three pointing one way, three pointing the other.  See picture above.
  • Take six “short” pieces (12″ pieces) from the pile created in Step 1.
  • Place one short piece in each “V”, forcing the “V” against the wall of the box.
  • Neaten up all the pieces so that they are as evenly spaced as possible.
  • Close the flaps and seal the box with tape.

Tip:  I’ve written this for doing one carton at a time.  It will go faster if you do it assembly-line style:  do all the “V”s, then do all the short pieces, then do all the carton sealing.

2.4  Fill the last two boxes, add the handles, and seal them.

Above:  An adequate setup for the handle.

Description:  You’d like to have a convenient way to drag these across the floor to where you need them, or to pick them up.  Adding a simple handle on both sides gives you an easy way to do that.  The only caveat is to make the exposed loop of the handle short enough that a crawling infant or toddler cannot stick their head through it.

  • Fill them as described above.
  • Tape your cord/twine pieces to one end (short side) flap as illustrated below.
  • Tape the box shut.
  • Add extra tape to eliminate the “bulge” where the handles protrude.

3:  Cut the hardboard

Time:  40 minutes.

Description:  Use the utility knife, straightedge, and clamps to cut the hardboard up neatly, so it can be used as a durable top surface for the steps.  If you follow these directions, you will not cut into the table beneath, so you don’t need to have your cutting board or plywood scrap underneath.

If you have ever cut sheetrock, this is roughly the same process.  You score one face, bend the board, and finish the cut from the back side.  The only difference is that you do NOT break the board by bending it.  You only bend it a bit, to help the process along.

Tip:  You really can’t do this well without firmly clamping that straightedge in place.  Ideally, clamp the straightedge and hardboard to the table underneath.  If you can’t do that, clamp the straightedge to the hardboard, and position the hardboard so that the clamps clear the table top.  In any case, position the C-clamps as far as possible from the cutting edge of the straightedge, to give the greatest clearance for the utility knife.

Tip:  At some point in this step, you may find yourself thinking that maybe having a nice new sharp razor blade in your knife wouldn’t be such a bad idea after all.  When that feeling hits, throw caution to the wind, spend the extra 20 cents it’ll cost you, and change the razor blade in your utility knife.

There is some scrap left after this.  You only need three pieces, 12″ x 36″.  You will end up with:

  • 4 pieces 12″ x 32″
  • 2 pieces 24″ x 16″

3.1  Score and cut the ends off both pieces.

  • Place one piece of hardboard on the table, good (shiny) side up.
  • Put two marks 32″ from the end, one on either edge.
  • Align and clamp the straightedge on those marks.

  • Run the utility knife down the straightedge many times, to score the hardboard.
    • Make the first cut with light pressure, and focus on keeping the knife tight to the straightedge.
    • Make subsequent cuts with progressively more pressure, deepening the cut.
    • Continue until you have made 15 passes down that cut.
    • After the 5th cut, the cut should be deep enough that you should be able to “zip” the knife quickly down the straightedge, without straying out of the cut.   I.e., you can cut down the entire length of the board, with heavy pressure, in about one second.
    • So it really doesn’t take that long to do the full 15 cuts.
  • Unclamp the straightedge and board.
  • Place the score line at the table edge and bend the board SLIGHTLY.
    • You are NOT trying to break the hardboard.
    •  Bend just until you feel or hear fibers breaking.
    • The purpose is just to widen the cut line to make it easier to cut, and to get the cutting point off the table.
    • If you try bend the board to (e.g.) a right angle, at this point, you will separate the layers of the board at the cut line and make a mess of that nice, clean cut.
  • With the board slightly bent, and the bend sitting off of the table, support the end of the board and continue to run the utility knife down that cut line, with firm pressure.
  • When you feel the knife start to go completely through the board, in spots, stop, bend the board into a right angle, stick the knife blade through from the back side of the board, and pull the knife straight up.  Flip the board top-for-bottom and repeat to finish the cut.  Keep the hand holding the board out of path of the knife.

3.2  Score and cut both boards into step-sized (12″ x 32″) pieces.

  • Take one 32″ piece of hardboard.
  • Measure and mark 12″ in from the long end.
  • Clamp, score, and cut as above.
  • Repeat.

4:  Assemble the steps.

Time: About one hour.

Description:  At this point, you tape the boxes and hardboard together to form the staircase.  The trick is to get this all nice and square and tight.  There is absolutely no one right way to do this.  Your goal is to end up with something that is both sturdy, and fairly neat.  If you are planning to decorate the sides of this, so that the tape will be mostly hidden, feel free to tape this more heavily.  I’m trying to do the least I can and still have a sturdy structure.

Tip 1:  It really helps to have two people to do this.  One keeps the boxes aligned, the other tapes.  This requires a lot of squeezing or pulling on the boxes to get them lined up well.

Tip 2:  If some of your boxes are a little “ugly” — maybe overstuffed-looking, maybe not totally square — hide them on the inside of the structure.  Save your nicest, squarest, most neatly-filled boxes for the top surface of the steps.  That’s where the squareness is most critical in supporting the weight evenly.

4.1  Tape pairs of boxes together, end to end.

  • Start with the two boxes with the handles.
  • Align the boxes.
  • Use a couple of pieces of tape, widely spaced, to tape them together, top and bottom.
  • Tape over the gap between the boxes on both sides.
  • Tape up the other five pairs.

4.2  Assemble the first layer.

  • Align three pairs of boxes.
  • Start at one edge.  Attach the tape near the edge
  • Squeeze or pull the boxes together, as needed, as bring the tape down along that edge.
  • Rotate the stack and do the other edge.
  • Tape the vertical gaps between the boxes.
  • Flip over and repeat.

4.3  Add the hardboard to the first layer

  • Find the better-looking end of the stack of boxes.
  • Place the hardboard on that pair of boxes, shiny side up.
  • Tape it all around — half the strip of tape on the hardboard, half the strip of tape on the cardboard.

4.3  Assemble the second layer, but not the hardboard (yet).

  • Same process.
  • But just two pairs of boxes.

4.4  Tape the second layer to the first layer.

Above:  This is me, compressing a box as far down as it will go.

  • Put the second layer on the first, and get it roughly lined up.
  • Line up one corner exactly.
  • Compress the box down as far as it will go
  • Tape that box to the one underneath.
  • Move to the opposite corner.
  • Repeat.
  • Do the 3rd and 4th corners.
  • Now tape the second layer to the first at the joints between the boxes

4.5 Add the hardboard to the second layer.

  • Same method as on the first layer.
  • You do this after you tape the layer down to avoid taping over the hardboard.

4.6  Add top layer, then add hardboard to top layer.

  • Same process as prior layer.
  • Just fewer boxes.

4.7  Go over all your visible tape joints.

Shipping tape is “pressure-sensitive tape”.  That means it really wants to be pressed down firmly in order to adhere.  Check all the visible tapes at this point.  They should all look clear, particularly the ones on the smooth hardboard surface.

In some places, where the boxes are mis-aligned, they may be poorly adhered (not stuck to the box, but standing above it).  That’s OK, and there’s nothing you can do about that.

Take a hard, flat object (the flat side of a roll of tape is ideal), and rub all those tape joints down, with firm pressure.

4.8  You are done.

 

Addendum:  Four step version with 4.5″ riser height.

As noted in the body of the post, the 7″ riser height may be more than some users can handle.  This section modifies the instructions to produce a four-step version with roughly 4.5″ riser height.

In a nutshell, buy 4″ tall boxes instead of 6″ tall boxes, and make the internal supports from some additional boxes.  Everything else is the same.

This will take about six hours to assemble, instead of four.   You now have to make up and assemble 20 boxes instead of 12.  All the times (except cutting the hardboard) should increase proportionately.

This assumes that you fill those boxes as completely as the 6″ boxes were filled.  It’s not clear that this is necessary.  The 6″ boxes seem stronger than they need to be.  But for the time being — until I put together another version of this — go with that.

Modify the materials list:  Replace the 6″ tall cartons with 4″ tall cartons, and add six more large cartons piecemeal (e.g., from Home Depot) or collect about the same square footage of corrugated cardboard from scrap cartons.

Modify Step 1: 

  • Cut the large moving boxes (or scrap cardboard boxes) into 4″ wide strips. 
    • Place the box flat.
    • Cut the flaps off, as before.
    • Measure and mark 4″ in from the factory edge.
    • Place the straightedge on the marks and cut.
    • Repeat, using the newly cut edge.
    • You want these strips to be as close to 4″ as possible.
    • When you get to the body of the box, cut it into 4″ strips, then cut the resulting “rings” apart in one place.
    • The Home Depot large moving box should get you 10 usable 4″ strips out of each side of the box, for a total of 40 strips per box.  You need six boxes to generate all 240 strips.
  • Be sure that the corrugations in the cardboard run up-and-down (in the 4″ direction) so that when these strips are standing up, the corrugations will bear weight.  In other words, at this stage, always cut across the corrugations.
  • Take the 4″ wide strips and:
  • Cut 120 strips that are exactly 12″ long.
  • Cut 120 strips that are about 18″ long.
  • If you run out of scrap cardboard, you can cut up no more than five of the 4″ tall boxes ordered via Amazon.

Modify step 2:  No changes, except that you now have 20 boxes, total.

Modify step 3:  No changes at all.

Modify step 4:  Add two boxes to the end of each layer, and make a total of four layers.  So the bottom layer has eight boxes, second layer has six, third layer has four, top layer has two.  Use all four “stair tread” pieces of hardboard, instead of just three.