Post 914: Fine-tuning the floor-to-chair aid.

Post #913 was a proof-of-concept.  It demonstrated that you can make a sturdy, portable staircase, suitable for use as a floor-to-chair aid, at home, using nothing but readily available materials and a few simple hand tools.  At modest cost.

That initial design has a lot of drawbacks.  It took a lot of time, used a lot of materials, had a lot of unwanted variation in the cut-up size of those materials, wasn’t really the right size, may or may not stand up well under the pressures generated by the pushup bars (used in lieu of grab rails.)

And so on.

So the point of this post is to fix what I can, to make this faster, cheaper, and better.

1:  I’m sticking with using identical new boxes, at least for now.

I’m sticking with the idea of building these up from packages of identical new boxes (via Amazon).  It gives them a reasonably finished look and, practically speaking, it’s the only way I can make up a set of instructions that somebody could readily follow.  Otherwise, I have no idea what the end user is working with.

2:  You can skip reinforcing the lower boxes.

Savings:  Roughly one hour of time, and six fewer cartons required for the 3-step model.

I suspected this was true from the start.  The corrugated cardboard in these cartons is rated to 32 pounds per linear inch in the “edge crush test”.  That gives a roughly 500 pound theoretical load, for these boxes, before they would fail, as long as that 500 pounds were spread evenly across the tops of the box walls.   (That calculation is based on this short Wikipedia article).

So I tested the theory.  I removed the internal supports from a box at the rear bottom of the stairs.  And when I sat on the stairs, nothing happened.  There is no perceptible difference between the side with all boxes reinforced, and the side where one box is not reinforced.

This works in part because the boxes themselves are strong enough.  But also because the first level of boxes — the part you actually sit on — serves to spread out any loads.

There is a risk here, in that the reinforced boxes are more robust to injury.  You could damage the box wall, and still have plenty of corrugated inside, holding up the box.  With unreinforced boxes, there’s just one layer of cardboard.  If it gets seriously damaged, the box could fail.

I considered adding corner reinforcements to the now-empty boxes, but commercial reinforcements are only sold on large lots.  The alternative of gluing up reinforcements, from layers of cardboard, is unappealing.

For the time being, I’m doing nothing.  I think these short boxes are robust enough on their own.  And if a sidewall gets damaged, just cut out the old box and put in a new one.

This has a lot of benefits.

This reduces the burden of cutting and carton assembly roughly in half.  And means that you save six cartons’ worth of cardboard.  It also makes for a neater overall look, as there will no longer be “overstuffed” cartons that bulge, below the top level of cartons.  It lowers the height of the steps because the tops of these boxes no longer bulge.  And it allows me to customize the height of the steps much more easily.

3:  Pay more attention to form factor/box size; customize step height if needed.

The prototype turned out with steps that are too tall.  I naively thought that a 6″ box would yield 6″ steps.  But in fact, a 6″ (interior dimension) box is actually 6.5″ tall.  Add in some “bulge” from over-cut support pieces, and the steps average just under 7″ tall.

Assuming I can eliminate the problem of bulging boxes, and noting that the hardboard only adds to the height of the first step, I now know what my options are, using stock cartons.

I can find 3″, 4″ and 5″ tall cartons whose other dimensions would work for the other dimensions of the staircase.  Each step adds a foot to the length of the staircase.  I’m assuming that 4′ long is the practical limit, but that’s just a guess.  With those constraints, to get the top step near a common wheelchair seat height (18″ to 20″), I only have three options using stock (uncustomized) boxes:

  • steps x rise, total height
  • 4 x 4.5, 18″
  • 3 x 5.5, 16.5″
  • 3 x 6.5, 19.5″

Anything other rise height or total height would require me to cut down the boxes to a custom height.

If I had to redo the current staircase from scratch, I’d just buy shorter boxes.  As it stands, rather than waste the boxes I have, I think I’m going to shorten them.  This will also be a test of whether or not I could conveniently build one to some exact specification for riser height.  It’s not hard to reduce the height of an empty cardboard box.  Tools for doing that are readily available for under $20 (such as this one, from Amazon).

The only difficult part is resizing the very first step, because that one requires resizing both the carton and the reinforcing cardboard in the carton.

Which brings up the next point.

4: Create a cheap jig for making accurate cuts in the cardboard.

The need for perfectly-cut interior supports is a real drawback.  Uneven supports weaken the load-bearing capability and they make the boxes bulge, which makes the final assembly tough and makes the results look slapdash.  In the prototype, I sorted the supports by size.  But what I really need to do is cut them the right size in the first place.

There does not appear to be a commercially-made “knife guide” to meet my needs.  Searching for “knife guide” bring up kitchen appliances and sharpening aids.

But, in a mini-quest, I think I can easily make one.

  • Take a $3.00 piece of metal corner bead, from Home Depot,
  • Hacksaw into three pieces.
  • The finished device, when viewed on end, will look like an L,  followed by a closely-spaced L and backwards L.
  • The factory cardboard edge rides within the first L.
  • The L and backwards L form a knife slot, duct-taped together, spaced by a couple of used utility knife blades.
  • The whole assembly is connected together by strips of cardboard at either end, slit to hold the knife slot at the exact right distance.

In addition to making the cutting more accurate, I think this will also speed it up considerably.

5  Modify the reinforcement in the top boxes, the ones you actually sit on.

I decided against this.  I’m keeping this the same as it is in the prototype.

The top boxes have to distribute fairly intense point loads from the pushup bars.  And they take high transient dynamic loads as the user moves up and down the stairs.  So this is the part of the staircase that needs reinforcement.

I’m not thrilled with my current method of little cardboard “V”s.  But I’m not seeing anything that looks like it’ll work better, for the same or less effort.

I ended up with the “V”s because I tried to do the standard rectangular interlocking grid reinforcement, but that took vastly too much time.   (As a means of reinforcing a box, a grid is more efficient than “V” because the cardboard supports are absolutely evenly distributed.  But it just takes too much time to produce all that grid from raw cardboard.)

I considered non-cardboard materials for the support, but didn’t find any that met all my criteria (cheap, strong, fast, recyclable).

Spray foam would be expensive and of unknown durability.  It would take roughly two cans of Great Stuff spray foam to fill one box.  (Calculated from this source — each can produces about .31 cubic feet of foam). And that would also mean that the boxes could not be recycled.

I may yet try insulating foam board.  That’s lightweight, cheap, and durable, but very tough to cut well with just a utility knife, and even tougher to cut to an exact size with a knife.  That would also require removal before recycling the cardboard.

All things considered, other than cutting the pieces to an accurate 6″ height, I’m sticking with what I have.

6)  Stiffen up the top surface.

The hardboard panels on the prototype serve three purposes.

First, they stop high point loads from puncturing the cardboard.  E.g., think how easy it is to drive a ball-point pen into a cardboard box.  So they prevent accidents like that from trashing the sitting surface.

Second, they provide a slick and wear-resistant surface.  This both helps the user to maneuver, and prevents repeated use from rapidly wearing through the cardboard.  (The tape, on the other hand, is a different matter.)

Third, they help to spread the loads over a larger area.  But they do this poorly, because the hardboard panels are themselves quite flexible.  For example, if you try to walk on this staircase, you get an unacceptable level of deflection of the step surface under your feet.  Your weight is simply not spread out enough for the cardboard to take the load without deforming.

To spread the load, ideally, you’d have a very stiff top surface, one that wouldn’t readily bend.  The stiffer it is, the better it will spread the load.  And that matters greatly, because the entire strength of the steps comes from spreading the load over a large amount of corrugated cardboard.

I used 1/8″ hardboard because I knew I could cut that by scoring it with a utility knife.  I didn’t go with something stiffer (plywood, say) because it’s too hard to cut (or cut well) with simple (non-power) hand tools.  (And it makes a mess when you cut it.)

I’ve looked at options for a stiffer step (1/4″ MDF, gluing multiple sheets of hardboard together, creating foam-core hybrid materials using insulating foam and hardboard, using thin plywood) and they all have drawbacks (that I won’t bother to detail).

Instead, I’m going to take the scraps of leftover hardboard and add a second layer of hardboard on the outside 10″ of each step.  These will be the “landing pads” for the pushup bars.  Those bars will exert considerable point force, with the user’s entire weight resting on the eight small feet of the pushup bars.  With a 200 pound user, I can plausibly expect a static load of 20 PSI and a dynamic load of twice that.  Whereas the user’s rump will generate no such high point loads.  And so, any reinforcement of the surface needs to go on the ends.

7  Try duct tape.

’nuff said.

8 Try a different assembly routine.

It would be nice if all the tape joints were visible from the outside.  That way, if a box got smashed, you could easily cut out just that one box and tape a new one in its place.  It also took quite a long time to assemble all the boxes, and I have to believe there’s a quicker way to do that.

9  Conclusion

I think that’s it.  Those are all the changes that are believe are feasible for me to do.  So the revised instructions would look like this:

  1. Choose your box size/form factor.
  2. Order your pack of boxes from Amazon.
  3. While you wait, make up your knife guide for accurate cuts.
  4. Buy the rest of the materials locally.
  5. For the three-step models:
    1. Assemble 6 empty boxes, two with handles.
    2. Cut up 6 boxes into strips, or cut scrap boxes into strips.
    3. Assemble and pack 6 boxes with internal reinforcement.
    4. Cut up 2 hardboard sheets (several additional small cuts now required).
    5. Assemble the staircase.
  6. For the four-step models (after buying one more sheet of hardboard).
    1. Assemble 12 …
    2. Cut up 12 …
    3. Assemble and pack 8 …
    4. Cut up 3 hardboard sheets …
    5. Assemble the staircase.

I am guessing that with the reduced amount of cutting of supports, the jig to speed the cutting, and so on, that this will now take under three hours.  And require less effort.

I’ll rebuild the existing staircase tomorrow.  And I’ll build the 4-step 4.5″ riser model when the boxes get her via Amazon.

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

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

Post #891: Cardboard, again

This is an intermediate step in the production of a D-I-Y aid for wheelchair users.  The background can be found in Post #886 and Post #887.

The question is, just how hard is it to make a lightweight cardboard object capable of supporting a person’s weight? I know that it can be done, in theory.  But sometimes you just have to see it to believe it.

The answer is, it’s not hard at all, to make a cardboard structure that will stand up to the weight of an adult.  Hence, the brief piece of performance art below that I call “fat man stepping on a cardboard box”.

 

What you see above is an example of the “structural grid plus envelope” method for creating corrugated cardboard structures (Post #887).  Except I didn’t even bother to create a grid. I just tossed in a bunch of strips, cut to height, and folded into “V”s.

If that works, as sloppy as that is, it’s going to be a piece of cake to make a set of steps capable of supporting a seated adult.

In fact, the challenge here wasn’t even in supporting the weight.  The biggest challenge was getting those strips cut to a uniform width, so that the weight would be evenly distributed.  But even with all the sloppiness, it’s obviously no big deal to construct something out of cardboard that will support the weight of an adult.

 

Post #807: A vastly simpler mask liner using Filtrete ™

Source for base data: 3M, ASHRAE.  See Post #593 for writeup of these and other filtration standards.

I’ve done several posts about making masks out of Filtrete ™ home air-filter material.  Each time I return to that task, I find simpler ways to work with Filtrete ™.

In this post, I’m going to show just how easy it is to take a Filtrete ™ home air filter and make some simple, flat, easy-to-handle, fiber-free pieces for use inside cloth masks.  In a nutshell, extract the Filtrete ™ fabric from the air filter and hot-glue it between two layers of the thinnest synthetic fabric you can find.

Then end-user can then cut it to size, for use as a liner for a cloth mask.  That seems to work just fine, and nothing more labor-intensive is needed.  The materials run well under $0.25 per mask liner, depending on what size filter you buy, and how large you cut your mask liners.

A few tips and tricks for doing that are given below.  Of which, the only one that might not occur to you is to use kitchen “parchment paper” as a non-stick surface as you are gluing.

Continue reading Post #807: A vastly simpler mask liner using Filtrete ™

Post #790: Cigarette smoke does not work as a test for mask filtration ability

Way back in Post #750, 7/9/2020, I had the notion to use cigarette smoke to test the ability of masks to filter out aerosol-sized particles.  There is a need for some sort of home test, because it’s next-to-impossible to tell how well or poorly any off-the-shelf mask works.  That’s particularly true for the “KN95” masks now being sold in everywhere (Post #747).

The theory seemed sound.  Cigarette smoke particles are about the right size, and in the past, some people did in fact use N95 masks to try to avoid second-hand smoke.

Now, having executed this test on my back porch this afternoon, I can attest that it doesn’t work at all. I can smell cigarette smoke strongly right through a genuine (but quite old) 3M N95 respirator (upper left, above).  And I could not tell that the smell of smoke was any stronger when I used a worn-out 3M N95 dust mask (next), or a dust/surgical mask (blue) with no aerosol filtration capability. Continue reading Post #790: Cigarette smoke does not work as a test for mask filtration ability

Post #780: Making an aerosol-filtering respirator from a dust mask and Filtrete (r) 1900

This post shows one way to upgrade a common dust mask so that it filters aerosol-sized particles.  The basic idea is not exactly rocket science:  Cover it with something that filters aerosol-sized particles. Continue reading Post #780: Making an aerosol-filtering respirator from a dust mask and Filtrete (r) 1900

Post #G14: Garden update

Source:  My garden.

If you have no interest in gardening, skip this.


Squash Vine Borer.  Looks like the SVB season is over.  I spend a lot of time walking around my garden, and my last sighting was 7/25/2020.  My first was 7/5/2020, making the SVB season just about exactly three weeks long.

My spraying regimen — I would term it spinosad with a side order of neem — appears to have worked so far.  In the sense that none of my many cucurbits is showing symptoms of SVB infestation.  Yet.  So that’s 0.008% spinosad solution (made up from concentrate), sprayed on the stems of my cucurbits every five days or so.  In the late evening, to avoid the bees.  Plus one random spraying with 100% neem (the variant that contains the insecticides, not the “hydrophobic extract” that’s just oil), more out of paranoia than from any thought-through plan.  I’ll have to keep up the spray for another week or so to account for the lag between egg-laying and hatch-out.


Powdery mildew.  I have that on nearly all my cucurbits now.  I should have been taking preventive measures, but I didn’t, so now I’m playing catch-up.

I tried baking soda (sodium bicarbonate) solution, once.  Recipe given in earlier posts.  I tried potassium bicarbonate solution, once.  Just substitute K for Na in the recipe.  If those had an effect, it was fairly subtle.

So I’m pulling out all the stops and following the hydrogen peroxide regimen as outlined on The Rusted Garden blog.  See the video above.  (Seriously, look this guy up on Youtube.  He’s in Maryland.  If you’re not envious of his garden, you’re a far better gardener than I am.)

This involves pruning out any leaves that are badly hit with powdery mildew, then spraying daily with a dilute solution of hydrogen peroxide.  (Around) 4 to 6 ounces of 3% hydrogen peroxide per gallon of water.)

If nothing else, this is certainly cheap.  A quart of 3% H2O2 is $1.29 at the grocery store, and is enough to treat my entire garden four times.  I’ll post in a few days and report back the results.

Ongoing, I’m also pruning my squash and pumpkin plants.  It never even occurred to me to do that.  (I’m kind of a laissez-faire gardener, which is another way of saying, I do as little as possible.)   But after listening the the logic behind it and seeing the results on The Rusted Garden, I’m all in.  As with the mildew issue, I’m running behind, so this will be an ongoing process.

I’m planting mid-season replacements for some of my cucumbers.  That’s another thing I’ve never done before.  To me, you plant in the spring, you harvest in the fall.  But apparently that’s not what smart gardeners do.  In this case, my Spacemaster 80 cucumbers were incredibly productive, until the simultaneous effects of bacterial wilt and powdery mildew got hold of them.  They are now such a mess that I’m pulling them out and replanting.  Apparently, with warm soil and a bit of fertilizer, there’s plenty of time to have them grow up and produce cucumbers before first frost.


Cucumber beetles and bacterial wilt.  Today I was 4/4 (attempts/kills) when inspecting my squash and pumpkin blossoms, long-nosed pliers in hand.  (As described in Post #G13).  I think that I have seen no new cases of bacterial wilt these past few days, but it’s hard to say, as it takes some time for the plant to die off.  In any case, I’ve gone from finding dozens in one pass through the blossoms, to consistently finding maybe four or five.  Tentatively, I think I’m winning.

Timing is fairly key to this operation.  The limiting factor is grumpy bumblebees.  If I get out there at 7 AM, there are bumblebees  just kind of sitting in the squash blossoms, zoned out.  My wife swears that bumblebees sleep in squash blossoms.  (Aww!)  I, by contrast, thought that was way too cute to be real.  A quick google search shows that she’s correct.  Not only do they sleep in flowers, but squash blossoms are preferred due to size and configuration, and squash blossoms provide considerable protection from the cold.  Snug as a bee in a blossom, no joke.  The upshot is that I have to wait for them to get up and go to work before I can patrol for cucumber beetles.

Tomato ripening is now occurring generally across my tomato plants.  Slowly.  My cherry tomatoes are ripening a few at a time, and some Rutgers tomatoes are finally turning pink.  Still going slowly, though, that’s for sure.

And the deer have not yet returned. As evidenced by the fact that I still have standing sunflowers, above.  On net, I’m crediting Bobbex deer repellent.  It really stinks!  I think the motion-activated radio comes in a close second (Post #G07).  I don’t know if it scares the deer, but it sure manages to scare the pee out of me every time I inadvertently trigger it.

Post #G13: Garden update

Not everything in my garden is a problem.  I just tend to talk about the issues that I’m trying to solve.  I’m attempting to achieve some balance here.  Topic below, in order, are:

  • Deer (success),
  • Birds (limited success),
  • Cucumber Beetles (apparent success);
  • Squash vine borer (possible success, possibly too soon to tell),
  • Powdery mildew (no success at all, yet, but I’ve learned to prune my squash).

Continue reading Post #G13: Garden update

Post #747: Can Kents clarify KN95 chaos? Updated

Source:  Depositphotos.com

Update 2:  This didn’t work, at all.  Not even a little bit.  See Post #790 for details.  You can’t use the odor of cigarette smoke to test mask filtration.

Update:  See postscript at bottom.  The ability of genuine N95 masks to filter smoke particles is well known and well documented.  In that light, my proposed “sniff test” for KN95 masks looks fairly promising.  To the extent that a mask reduces the odor of cigarette smoke, then it is filtering out virus-sized particles.

In Post #740, I noted that my local convenience store had “KN95” masks for sale.    I’ve heard a rumor that one of the local hardware stores is also selling such masks.  (I plan to check that out soon.)  And I exchanged emails with  neighbor who is in the process of purchasing some KN95s, from a couple of different sources, for daily wear at work.

In theory, wearing a KN95 gives you the same protection as an N95 respirator.  So, in theory, upgrading from a cloth mask or similar to a KN95 is a smart thing to do.

In practice, not so fast.  I’ve started looking into the “KN95” mask market, and it is complete chaos.  I guess that’s no surprise.  That’s more-or-less of a piece with the entire Federal response to COVID-19. Continue reading Post #747: Can Kents clarify KN95 chaos? Updated

Post #G07: With my luck, the local deer are all Garth Brooks fans.

Source:  Clipart-library.com

This is one of my occasional posts on gardening.  In it, I’m going to explain how to take an off-the-shelf plug-and-play motion sensor and turn it into flexible device for deterring deer.

As anyone who gardens in this area will tell you, deer are pests.  Cute as all get-out.  But pests, nevertheless.  And, unfortunately, either they can’t read, or they just don’t obey signs.  So unless you want to feed the local deer, either you erect some serious fencing around your garden, or you do something else to convince your local deer to feed elsewhere.

What I describe in this post is one of several deer-deterrence measures I have taken.  They seem to be working so far.  But I haven’t seen any elephants in my yard recently, either, and that doesn’t mean I’ve found a good elephant repellent.


Background

 

Source:  USDA

At the end of March, I decided to put in a big vegetable garden.  Just to have something to do during the pandemic (Post #580).

I recycled my “MAC” signs into raised beds.  Figuring, if there was no longer a MAC ordinance, I’d have to get signs reprinted anyway (Post #G05).  And that’s how things did shake out, this past month (Post #706).

 

Above, that’s the same garden, today.  Note the complete and total absence of deer!  The red arrow points to my latest deer deterrent.  That’s a trash bag covering up an indoor motion detector.  That’s what I explain next.


Making a flexible deer scarer.

There are some things that absolutely will keep deer out of your garden.  A tall and sturdy fence.  A shorter fence, if you can plant enough shrubbery around it to prevent the deer from jumping it.  A two-layer electric fence.

I didn’t want to do any of those and/or they were illegal and/or my wife didn’t want that in the back yard.  Not that I can blame her.  Nor was I willing to buy a few hundred dollars in supplies, and put in hours of labor, to produce a few tens of dollars of vegetables.

Any cheap and easy deer deterrents are likely to be, at best, partially effective.  I’m not going to run through all the commercial and home-made deer deterrents, except to say that a) there is little agreement on effectiveness of most of them, and b) the conventional wisdom is that deer will get used to just about any un-changing device designed to scare them.

I had several deer deterrents in use, and they seem to be mostly effective.  This includes Bobbex deer repellent, a Yard Enforcer motion-activated sprayer, some older ultrasonic “pest scarers” that seem to be useless and/or broken.  Liberal use of blood meal throughout the garden.  And, of course, the classic of low-end DIY deer repellents — bars of Irish Spring soap. (Manly, yes, but deer hate it too.)

I decided to add a motion-activated noise/motion device of some sort.  Just something to startle the deer as they chow down on my string beans.  But didn’t really find what I was looking for as a commercial product.  So I decided to make one.

My first attempt failed.  I tried to make one out of a cheap motion-activated floodlight.  Figured that, in place of the floodlights, I’d just put in some screw-in sockets, and then plug something into that.  But modern motion-activated floodlights are all (or nearly all) designed to turn off during the day.  Basically, a) they don’t work in daylight, b) everything that I tried to block the daylight also messed up the infrared-based motion sensor, and c) I ended up ruining the unit when I tried to drill out the wired-in cheap light sensor (literally, just an LED).

Not only did I not figure out how to defeat the nighttime-use-only problem, those require a lot of additional parts, and they require having an electrical box.  And the cheap one I got from Home Depot was clearly going to require a lot of sealant in order to be weatherproof.  And, owing to the electronics of the motion sensor, there are limits on what sort of electrical/electronic device you can control with that.  All in all, too complicated and too clever by half.  But designed for outdoor use.

Here’s what saved the day.

Source:  Amazon.com

My second attempt worked perfectly:  I used an off-the-shelf plug-and-play indoor motion sensor.  What you see above is an indoor motion sensor with a roughly 25-foot range.  It has no problem working in daylight.

As importantly, this device has no problem “seeing” right through a thin plastic bag.  So all you need to do, to use this outside, is set up whatever you are going to set up.  Then put a white garbage bag over it, to keep the rain off the electronics.

What’s more, it’s electrically bulletproof.  Some light controls used electronics to turn the lights on and off, and so have significant limitations at to the type of device they can control.  (E.g., some on-at-dusk, off-at-dawn controllers can’t deal with compact fluorescent bulbs).  But this device uses a physical relay to turn the electricity on and off (you can hear it click).  That means there are no restrictions (other than total wattage) as to the type of electronics it can control.  And it can handle up to 1200 watts.  That means you can use a wide range of household devices as noise-makers.  For example, I could plug my Shop-Vac into this.

With this part in hand and tested, the rest of the deer-scaring device is straightforward.  Put a stake in the ground where you want to use this.  Run an outdoor extension cord out to your garden, plug this in, mount it to that stake.  Plug the device of your choice into this.  (Or use a multiple tap, and plug in several devices).

Then cover the whole assembly with a white plastic trash bag. When a deer walks by, it will now trigger whatever device you have plugged in.  For the amount of time you choose.

For my first round, I’m following a recommendation I’ve seen in several places, and have hooked this up to a radio.  Then I put the radio in a small metal garbage can.  That keeps the water off the radio.  I have it set, very loud, to WMZQ.  Now when a deer tries to walk up to my beans, it is greeted with one minute of loud country music.  Which then stops.  And if they are still there, it runs for another minute.  And so on.

It’s far enough into the yard that I don’t think I’ve created a neighbor-annoyance device.  But if you’re standing right next to it, the effect is pretty startling.

The nice thing is, if the deer get used to this, I can just change out the radio for something else.  Maybe a weed whacker next time?  And there are all kinds of sound-and-motion possibilities using a Shop-Vac exhaust.  Maybe some flashing lights.  Plug in a three-way tap and operate three devices, subject to the 1200 watt limit.

Basically, anything you can plug into a standard wall outlet, and that doesn’t draw too much current, can serve in place of the radio.  Which means you can keep it fresh, for your deer.  And keep them from getting used to this deer deterrent.