Trash bag adapter Mark IV

Mark III is the same using Crius clips only.  It's not bad but without target for the trash bag to clip on to.  This one adds 4 tees just as marks for the 4 corners of the trash bag.  And since they are tee's, the bag can be securely held on position with a small section of pipe plugging into the tee.

Because the field modified dimensions last time wasn't updated on the spreadsheet, I was wrong by two inches.  I find it useful to clip the trash bag onto the frame at two more locations, forming a hexagon.  The new shape is better, if only there's less length for the trash bag to slack.  So, there will be mark V with the clips replaced by tee's.

Defeating the Flushmaster patent: automatic toilet bowl cleaner

You really never have to brush the toilet bowl again for less than $1.  You only need to open the toilet tank maybe once every 6 month and drop some super cheap household chemicals in it.

My previous improved version of the Flushmaster split the water from the fill tube into 2 paths, but still using the Flushmaster.  It was a temporary fix for prove of concept.  Once the concept is proven, using the Flushmaster is totally unnecessary, overly complicated, inconvenient, and unreliable.

Since my new design is patentable, I look up the patents reluctantly.  Reluctantly because there's not much money to be made because everybody can build it for less than $1.  But still, many people will still want to just buy and drop one in the tank and forget about it.  Fortunately, Flushmaster has already patented the concepts in 2007, so I can disclose my findings immediately and not spend my time in the toilet business.

The current Flushmaster gadget is patented about 2001.  Why they don't give you products with the new 2007 patent? Money!  Now the refill cartridge sells for $7 (?) and last for about a month for a large family with older high flow toilets.  That's totally not bad if you don't have a cleaner/house keeper.  That's a steady revenue stream that the new produce will decimate.  And if you see the new thing, probably you want to copy it for less than $1.

Overflow tubes are 1" pipes slightly narrower than standard PVC 1" pipes.  So the whole thing is based on 1" pipes and fittings.  In this final assembly, the Tee on the right just slides onto the overflow tube.  Nothing is needed to modify permanently any existing fittings.

For this design, the chamber on the left stands on the tank bottom.  This is not necessary.  To secure the assembly in place all you need to do is to glue a 1" coupler to the Tee on right.  That will hold anything securely in place using the overflow tube itself.

The whole assembly need to be water tight so the chemicals don't leak a lot into the tank.   Since the assembly is not under any pressure, you can just use PVC glue to put them together without worries.

Water from the fill tube is split into two branches.  The main branch goes into the top of the Tee on right, via a 1/4" hole, drilled with a plastic drill tip so it doesn't slip during drilling.

The 2nd branch fills the chemical chamber, via a dripper or flow restricter or narrower tube or you don't even need a 1st branch.  When the chamber overflows, the cleaning solution goes into the flow tube.

Since the overflow tube and the 1" Tee is only loose fit, I put some plumber's pudding on the edge of the flow tube to seal, so chemicals can't leak into the tank.  I don't think you need it because instead of NOT allowing drop-in-tank cleaner manufacturers to destroy flippers and gaskets, the new standard seems to require everything in the tank to withstand cleaner chemicals.  I spend time for this new design because chlorine destroys drippers for gardening drip irrigation.  It only lasted for a couple of months though it is dirt cheap.

If your fill valve ever malfunctions, water goes into the overflow tube horizontally via the Tee on right.  The "critical fill level" changed a little but you can adjust it.  I think this is or can be plumbing code compliance.  A simpler gadget will be based on 3/4" pipes and fittings.  A 3/4" tube goes nicely and tightly into the overflow tube.  There is no possibility of leaks.  But the effective overflow tube size is reduced to 3/4".

1" chlorine tablets simply drops into the chamber.  But I am experimenting with something better.  Let's see this in the tank. (The old Flushmaster is there totally unused.)

Recap: standard 1/4" pipes, for fridge icemaker or gardening drip irrigation goes straight into the white fill tube.  Pick the slighter tougher ones and you can insert it far into the fill tube, forming a water tight joint.  You also need a 1/4" tee and a dripper.  I'm experimenting with the flow rate but currently I have a 2 GPH dripper.

I have an older version that uses 1" chlorine tablets.

To reduce the swimming pool smell, you can make the tank lid reasonably air tight, or you can use a standard 1" plug to cover the Tee at the chamber opening.  The dripper is inside the plug so it will not hinder the chlorine tablets when taken out with the plug.  I rotated the chamber so it is lower profile to fit into the tank with the plug half in.

Chlorine tablets can go through standard 1" pipes, tees and caps, but NOT plugs.  So you have to allow enough space if you use plugs instead of caps.

I do not recommend expensive 1/4 tee's.  It's easy to take the tubes out but only when not inside the tank for months.  Drip irrigation tee's are much cheaper.  If you ever need to disconnect the tubes, cut the tubes, discard the tee and the tubes.

To really reduce the chlorine smell, like any drain you can add a u-trap at the open tee.  It's clumsy for 1" fittings but there's should be enough space for that.  The u-trap should be refilled with fresh water every flush.  The top level of the u-trap should be slight higher than the overflow tube so water will go into it rather than the tank.

Again, there's nothing wrong with the Flushmaster, but you can be environmentally friendlier.  First, they use a lot more chemical than required.  Their new patent sort of admitting that, or, you do not need to buy expensive slow dissolving tablets to avoid refilling too often.  They design the rubber seal so flimsy that you cannot refill it yourself with chlorine tablets. You can at most reuse the o-ring a few times.  I have yet to find o-ring in hardware store to fit without using pliers to twist the cartridge out.  My design works at low pressure and you don't need any seals.

As for the new chemical, I can hint that it is very cheap and easy to find.  If your tank is larger you can fit in a few chambers and you might not need to refill in a year's time.  I have calculated the solubility of chemicals and nothing seem to last a week  unless you make some large crystals so they dissolve much slower.  But this is barking the wrong tree totally.  You'll see.

Miracle liner for pet cage and anything else

The miracle liner is polyester film such as Duralar.  It's like a sheet of paper but made of clear plastic instead.

The miracle?  It's easier to work with than paper.  It is tear and scratch resistance.  It stays flat, better than non-slip.  It's heat resistance and chemical resistance.  It's low cost.

Even if you brought a huge roll, it stay flat when you unroll it.  I know because I used it to cover the whole dinning table.  It's clear and you can write on it.  You can put it on a table or on the floor with a grid pattern on it.  It's extremely easy to align and measure the exact size.  Or you can trace the outline of the cage, or you can just cut freehand until the sheet fits the cage.
 
The sheet is slightly too thick for a paper cutter.  But it's extremely easy to cut with scissors.  It's easy to cut while following a straight line.  It's easy to make a smooth cut whether you cut is straight or slightly curved in multiple parts.  And since it's clear plaster, it's hard to notice that the cut is not perfect.

If the cage floor is reasonably fitted with a sheet from wall to wall, it's very difficult to take the sheet off because it stays flat from edge to edge, corner to corner.  My bunny toss everything and attack steel wires but he couldn't do anything to the sheets.  If the cage has some sort of "wall", it's better than non-slip liners.  It just couldn't slip pass the walls.

The sheets are extremely easy to clean.  I used rigid sheets before such as acrylic.  I have to soak them in acid to get the rabbit poop off.  It's a lot harder to cling onto flexible plastic sheets.  When the poop are dry, they will almost fall off by themselves.  Chemical free.  I suspect that there is something to do with it's diet and the strong sun.  In any case, this material is the most easy to clean stuff I ever used.  It will return to it's flawless clear state after cleaning.

Because it is cheap, I stack several of them.  It's non-slip even when stacked together.  When the top one gets dirty, I just lift it off and expose the 2nd sheet.  Then I dry the dirty sheet in the sun.  If you want to wash it clean immediately, you need some acid such as vinegar and citric acid.  Or, you can wipe the poop off with tissue paper whenever you see them.  It's almost perfectly clear again once you wipe it.

The sheets are slippery so the naughtiness of the bunny is reduced a little.

My cage floor is made with perfectly pre-cut to size wood pieces.  Polyester sheets are the perfect liner for that.

PVC pipe gadget techniques — no glue no screw

In building PVC pipe furniture and gadgets, glue or screws are often used.  I doubt it is necessary, and arguably weaken the structures.

If you insert a standard PVC pipe into a standard PVC tee, all the way in with a rubber hammer, it's almost impossible to pull it out, even for the thinnest 1/2" CPVC pipes.  To pull the pipe out, you have to have a clamp securely holding on to the pipe, and then twist the tee with hand or tools.  You have to twist clockwise and anticlockwise until the joint come loose, and then the pipe can be taken out.

So, in your end structure, if you can't twist the pipe against the coupling by hand, and there's no direct force to pull the pipe straight from the coupling, you don't need any glue.  This is easy to design and usually very natural thing to do.  For example, if you have one pipe jointing with two tees at each end, and they are of different orientation, you can't twist the pipe against anything else since the tees are fixed in space in the end structure.

The only way you can twist the pipe is to use a clamp directly on the pipe.  Even so, the force needed is great and don't do much damage since the pipe is still in the same position.

The disadvantage of glue is that it is usually toxic or at least contains some undesirable volatile compounds.  It takes time to apply and dry.  And the coupling cannot be reused.  If you don't use any glue, when you change your mind about the design, you just need to cut the pipe and twist it out with pliers.  All parts are reusable.

Some people drill through the coupling part and use bolt and nuts to prevent the joint from coming apart.  Any drilling will weaken the coupling and the pipe.  The nut and bolt will only be effective when the joint already come loose.  They don't come loose if designed properly.  In my roof top rack, a Christmas tree carrier, I don't even use glue or bolts.

Tips for plans.  To be glueless, the plan has to be precise.  I always use spread sheets to calculate the dimensions.  You need the dimension of your structure modified by the dimensions of the couplings.  For example, the top bar of the T character is about 2.5", the height of the vertical bar is about 11/16".  The extra pipe length to insert into the tee socket is 3/4".

I always use standard tee's and occasionally 90 deg turns.  They are much cheaper than the couplings designed for PVC furniture with more variety.  Arguably the standard ones are better too.  You can use two standard tee's to replace a 4 way coupling on the same plane, or a 3 way coupling in the x,y and z axis.  Even though a standard tee joints everything on one plane only, if your dimensions are reasonably accurate, you can put together a cube quite nicely and squarely.  You just hammer the pieces together with a rubber hammer and the pieces will fall in shape.

Tips for the ugly markings on the pipes.  I don't know why but the cpvc markings can be easily removed with sand paper or steel wool.  But it's almost impossible to remove the markings on white PVC pipes.  Solvents will remove the markings but stain the white pipe with whatever colour the ink is.  Most of my gadgets are by the wall and stationary.  So I just need to turn the markings furthermost from the usual line of sight.  It's almost totally hidden unless you go squarely at the back, which is impossible if the gadget is by the wall.

Tips for reusability and flexible joints.  If the joint depth is 0.75", and you want to joint two tee's back to back together, the best pipe length is twice that at 1.5".  If that part does not need to be structural and you want it to be taken apart with reasonable force, make the pipe length 1 1/4".  If the joint is for the purpose of a "lock", that you may take it apart occasionally, make the pipe length 1", and insert the pipe all the way into the stationary coupling first.  In this case, you can also make a hinge.

Trash bag adapter Mark III

Recap - use smaller standard trash bags in a big trash cart for robotic trash collection trucks.

Mark I uses a wooden rectangular frame.  It was too clumsy to detach the trash bag from it after full.

Mark II uses inexpensive clips to attach the bag to the edge of the cart.  The clips aren't that secure.  The bag slags.  And tall bags are needed.

Now the new Mark III uses PVC pipes of course.  Crius clips are used to attach the bag to the frame. Any known issues are improved. 

Is it better than using a separate standard bin? Time will tell.

Perfect low cost custom pet houses

You know I have been building things to improve my bunny house.  The last time he was living in a concrete block bunker with a big grass yard to himself.  That didn't solve all the problems.

I was going to custom made an acrylic house with all the easy to maintain gadgets.  It would be perfect for indoors and outdoors and while we are on vacation.  It was never done because the more I think, the more it's impractical.

Acrylic is expansive and you have to be precise to glue pieces together.

I have been building small PVC gadgets for a while and it suddenly dawn on me why I don't try to build a pet house from scratch.

I have been building very precise PVC pipe structures using only standard tee's at less than 30 cents a piece.  PVC pipes are virtually free - less than $2 for 10 ft.  With the help of a spread sheet, I can build very complex structures.

For pet house, the first problem is the floor.  You can use pipe grids as the floor but still you need something to cover the gaps.  You can use pipe grids for the walls but the total cost of tee couplings can be high, even at 30 cent a piece.

Wood is still the best choice for the floor.  This bunny house is for indoors so I paid for a premium board, so I can nail ready made side guards on it to prevent spills.  The board has to look smooth for indoors and can be painted if needed.  For outdoors a flat particle board will do.  The wood pieces are of standard dimension so I don't need to do any precise wood work (I can't as I only have a jigsaw).

For the walls I use 24 gauge galvanized steel wire forming a 2" grid.  It turns out to be a great idea and looks neat too.  It's easy to drill small holes into PVC pipes with a plastic bit.  I sand the holes briefly with an oscillator tool.

It turns out that it's easy to tie the wire onto the pipes and tighten them.  If you go around the same holes twice or more around the pipe, it will be securely attached.   Add a Cirus clip on the endpoint and you can secure it further.  After you tighten a length of wire, you can keep the tension by Crius clips as in the last post.  Then you continue to wire and tighten the next part.  You can wire the entire structure without one single wire without breaks.  But for modularity I wire only one side at a time, and use separate wires for vertical and horizontal.

This bunny has been known to attack chicken wires and succeeded.  He had a go on the steel wires but can't do anything to it, yet.  Because the wires are hand tight, he managed to put his head through the grid, but fortunately not his feet at the same time.  So, the cage is secure.

This cage is open top with walls two feet high.  But I decided to put in a door so the kids can do the daily chores too.  What you see in the middle is a toddler-proof door.  I still have to add some legs so the vacuum cleaner hose can get under it.  Also, it will be ideal if I don't need to bend down to feed him or clean the cage.

This is 20" by 3'.  I'll build a 2'x4' for outdoors.  It will be higher than the sprinklers can reach so we can put it in his yard without turning off some of the sprinklers.

You can clip anything on the pipes like sunscreen, rainproof sheets, blankets.  The outdoor one will have a roof structure.  You can see the Crius clips in the picture, near the lower left and right corners.

Crius clips - attaching anything thin or flexible to any pipes securely and economically

This is my new awesome "invention" - Crius clips.

You can secure a thin or thick gauge steel wire to any pipe securely without slipping.  There's no slipping.

You can attach a towel or a plastic sheet on to a length of pipe for shelter or projects.  Not even high winds can detach it.

Say if your pipe is 1/2" PVC, pick the next size PVC pipe, which is 3/4".   Use a pipe cutter to cut out about 1/4" length of pipe.  From this O-ring, cut out about 90 deg, or a corner.  The remaining PVC pipe is a Crius clip.

Place the C opening on the pipe you want to clip on.  Push the clip on with your finger and it will go in easily.  It takes two hands to take it back out.

The clip itself is always PVC pipe.  The pipe to be clipped on to is not limited to any material.  For example, for galvanized steel 1/2" EMT pipes, the best clip is to be made from 1/2" PVC pipes (the OD is slightly larger than the EMT pipes).

If you want to clip thick power supply cable or a thick carpet, use two size larger PVC pipes.

I'm into PVC and EMT gadgets and found numerous uses for this Crius clip.

Environment issues: The manufacturing and recycling of PVC involve toxic materials.  PVC itself is stable and harmless as used in drinking water.

PVC and CPVC are supposed to replace expansive copper pipes.  There's no going back to copper as I myself witness micro pores that can form on copper pipes.  This is a nightmare as a leak can develop in any length of pipe.  The leaking can continue for a long period undiscovered.  The reason is still unknown.

The newer PEX are superior in many ways.  But I heard that rats like them too?

PVC will be around for a while.  They are also used to replace metal and wood window frames for energy efficiency.  They are not that environmentally friendly but they last a long long time.  They can be recycled too.

I can't find anything to replace PVC furniture.  Metal couplings cost 10 times more, and they are bulky.

PVC produces toxic fumes when burned.  Ironically PVC window frames and very popular.

There are ways to reduce PVC in furniture though.  For pipes that don't need to be tight fit, you can use steel EMT pipes that is about the same price.  You can still use PVC couplings but they won't exactly fit.  You can use loose pipes, for example, for the horizontal support of beds.  Or for vertical grids to keep things in.