Tag Archives: tie

Block Press Construction and Measurements

After the camera fiasco the other day we finally found another camera.

This after noon I made another block and feel we have the one we want now.  It isn’t perfect and will still need some tweeking to make it work better.   But it is at a point where others can copy it and start making blocks.  Their experiences along with ours will help us find the final block making machine.     Bob Warner took a picture of the plastic block box machine yesterday and then put down all the measurements on the photo to make it easier for others to copy.

We have a bolt with a 15/16  nut on it so we can use a rachet to turn the Acme screw.  We were given a steering wheel from a bus today.  We might change out the bolt and nut for the steering wheel.  Eveyone that makes a plastic block box machine will find their own way of turning the Acme screw.  I think the steering wheel will be my favorite though.

http://www.mcmaster.com/#93410a632 is the part number and source for the Acme screw.  http://www.mcmaster.com/#94815a037 is the part number and source for the nut.  A substitute that might be available locally is scaffolding screw jacks.  http://www.affordablescaffolding.com/accessories.html?gclid=CKOCytL5_qUCFYde7AodXBOqow#screw_jacks The downside of using them is their length, usually only sixteen inches of travel available.  We’ve found the thirty six inches of travel about what you need.  Less than that will mean repeated compressions to get the pressure needed.

This is detail shot of the ram itself.  The three slots are the wire retainers.  You can see in the block box the wire guides.  The wires can’t be installed after the block is compressed, at least we couldn’t do that.  So we designed the machine to locate and maintain location of the wires during compression.

I welded half of a steel ball to the end of the Acme threaded rod.   I used a piece of pipe and a rounded piece of tubing from a tractor attachement  to contain the threaded rod.  I put in a grease zert to make things work better and live longer.  This gives a wide surface for the pressure applied by the threaded rod.  The grease keeps it smooth.

The threaded nut was welded into a hole cut into a piece of half inch plate that is welded to the back or end of the block box  Care must be taken to insure alignment with the ram as it travels down the block box.

Everyone will find a postion that works best for them when it comes to using the block box.  I find this position just about perfect for me.  It has enough angle so I don’t have to fight the plastic falling out like I did when it was vertical.  And it is easier to keep the plastic in place while loading than when the block box was horizontal.

This little tool was designed by Bob Warner for tying the loops in the ends of the tie wires.  The handle is three quarter’s inch round rod and the shaft is half inch pipe.  The tab is 1/4″ by 1/2″ by 3/4″.  A slot is cut into the end of the pipe to allow post tensioning by twisting of the tie wires if necessary.

The small tab is used to make a ninety degree bend in the tie wire.  We’re using 12 gauge galvanized tension wire.  It is stiff to work with but will last a long time.  It is designed for use with chainlink and livestock fencing.

Then using the tab and the round shaft a loop is made in the wire.

This rod with the slot in it is located at the top of the block box frame.  It’s part of a guide for gauging the length of the tie wires.  After Bob made the trick little tool is was modified to make the loop using the tool.

The ends of the loop are placed in the slot.

Using the tool and the slot the eye is made in the tie wire.  Pliers could be used to do the same thing.  But it wouldn’t be near as easy.  Especially with wire as stiff as the twelve gauge.

This photo shows the three tie wires placed in the wire guides in the floor of the block box along with being properly placed in the ram.

This is loading the plastic before we put on the lid.  As you can see the angle position makes this easier.

I did this by myself and didn’t take pictures of the cover plate in place.  The cover plate was put in place.  Once it was in place I shoved in more plastic, occasionally compressing it with the business end of a sledge hammer.  I did one full compression stroke and then filled it back up.  One more full compression stroke and I removed the cover plate.

This is the compressed block of trash plastic.  As you can see it would be very difficult with this design to install the tie wires now.

This is the tensioning tool.  It’s made using half inch round rod.  The slot on the end is critical.  It was made with a chop saw blade and at about an forty five degree angle.

The end of the tie wire is fed through the wire guide on the end into the block box.  The tied loop in the wire at the ram is placed over the block of plastic.  The loose end of the wire is pulled through the loop.  Then the end of the tensioning tool is placed through the loop about five inches.  The groove is placed over the wire.  The loose end of the tie wire is folded over the handle of the tensioning tool.  The handle is forced towards the bottom of the block box.  When the loop is over the end of the tensioning tool the tool is folded down onto the plastic block.  Excess wire is cut off and the end is loosely wrapped around the tie wire.  This is done to all three tie wires.

The ram is pulled back away from the block.  I find a small lever bar is all that is needed to remove the block from the block box.

These blocks are a nominal 8″ X 8″ X 16″ .  They can take abuse and maintain their shape.  They weigh six to seven pounds each and difficult to compress or distort.  Tied to together with wire and rebar they will make a great wall ready for plaster inside and out.

They are a future based upon our past.

Good News and Bad News

The bad news is the original press has some issues.  One of the problems is the sides are vertical and that makes getting the block out of the press difficult.  Another is it is difficult to remove the trash from the press between blocks.  And then there’s the wire guides, difficult to use when operating the press, too far apart,  and generally awkward to use.

The good news is

I spent some money for some more materials.  I decided to use three wires for the new version of the blocks.  The size is the same.  But the new press has the outside wires closer inside and then I put in a middle wire to contain the middle bulge we get.

I’m trying to get the machine down in cost material wise.  I also want the materials to be as common as possible so that the presses can be made on site if necessary just about anywhere in the world.  I’m trying 11 gauge 2″ X 2″ square tubing for the floor and base end.  I hope this will be substantial enough to hold up over time.

If you look close you and see I”m using quarter inch spacers between the tubes for wire guides.  I believe this will simplify the compression phase because the tie wires will be lying out of the way.  The tie wires will still have to be attached to the ram.  But we won’t have to fight keeping them in the guides like we did with the original press design.

I’ve decided to put an eighth of an inch taper in each side to make removing the completed block easier.  The top has an 8 ” inside measurement.  And the bottom measures 7 3/4″ inside.

We’ll be making blocks with the new design tomorrow if everything goes right.