THE OLD WIZARD GYPSUM

Lathe in a home workshop is not a luxury but a primary necessity: the fact of the matter is necessary to produce parts that are in the geometry are called solids of revolution. But is it really impossible to do without a lathe? Not to remember us on the old, reliable, easily formed material — plaster. There are many details that there is no need to sharpen the cutter for hours to iron with sandpaper, polishing, etc. and all they could be plaster. Working with plaster is much easier than with wood or metal, and “machine” for this can easily be done in just a quarter of an hour from a sheet of thick plywood or chipboard in the center of which is inserted the axle — a metal or wooden rod. Still need a “cutter” — a plywood template with a metal cutting edge. The contour of the edge must correspond to half of the cross section of future products, for example, the layout of the wheel.

Moulded half wheel rotating around the axis pattern: excess plaster is removed and the result is a workpiece of perfect shape. Then the two halves are glued together with a liquid solution of gypsum, and the whole wheel finish. If the suggested layout as close as possible to nature, the wheel is processed with sandpaper and painted by nitroenamel.

 

The axle is also possible to carve plaster, just like all items with small ratio of diameter and length shafts, axles, tubes, etc. For their manufacture required a machine with a removable horizontal axis of rotation — the spit and motionless, fixed in the grooves of the machine template. The base also serves as a thick sheet of plywood; the spit is of steel rod of suitable diameter. To secure the cast, the rod is wrapped in soft steel or copper wire. Rotating the handle and gradually increasing gypsum layers on a spit, the resulting solid of revolution configuration, approximately corresponding to the profile cutter template.

 

For details of relatively large diameter, it is recommended to use a frame shaped like a hamster wheel. So it does not rotate on the axis, at the point of joining with the frame hammer square. If the frame needs to be removed from the part after its manufacture, then it is pre-pasted several layers of paper.

Now we will tell you how to make plaster models of angles, channels, rails and other dinnermenu profiled elements. First, we produce “rolling mill”. It is a flat Board with attached guide rail. According to the latest slip template that specifies the cross section of future products. To ensure Squareness of pattern to the guide, to it are attached two struts — a small wooden plank.

 

Obtaining the right profile is about the same as in the previous two cases: the Board surface is placed a plaster solution, the excess cut off when drawing the template along the guide rail. It is necessary to consider only that surface quality is obtained by movement of the pattern in the direction of tin nailed to it cutting edge.

 

And if you need to make several identical parts? In this case, it makes no sense to copy as previously described. Enough to make one piece and on it as the model to cast the required number of “twins”.

 

 

 

 

 

 

 

 

Odinocestva form:

1 – Foundation, 2 – clay, 3 – limiter strap, 4 – gypsum 5 – ring, 6 – form, 7 – Tsvetnye holes to eject

molded details.

 

 

 

Dvuhmetrovaya form:

1 – the first layer of plaster, 2 – model, 3 – hole,-lock, 4 – second layer of plaster, 5 – year-olds.

 

The simplest form — odinochestva. All the technology will follow the example of casting a simple ring. For starters carved in the first method, ring, finally treat it and paint nitroemalyu. Then lay the ring on a sheet of plywood. Below the gypsum, from which will be cast in form, did not spread around the sheet of plasticine, clay or plaster will stick to the restrictive strap. Now the inside of the resulting box and ring oil stearin with mastic and cover with a plaster solution. After curing remove the strap, casting perevernet and remove the model.

 

Carefully inspect the inner surface of the mold. If necessary, tweak it, color — form ready for distribution details. It remains only to cover it with fondant and pour a plaster solution. Before each subsequent casting also carefully inspect the inner surface of the mold (whether it is damage) and lubricate it.

 

If you want to get more complex detail (e.g., the wheel), then the form will have to do two halves connected “castles”.

The order of operation in this case is the following. On the surface of the plywood sheet gather already familiar to you box, lubricate its inner surface is plastic and half the HEIGHT complete: a plaster solution. Precede;’ Cho prepared (painted and Simandou) model into the plaster to the line PR;.-g, believe contact. Align the surface and her shovel, select a few holes — “castles”. After curing of the plaster parting surface paint nitroemalyu and apply the mastic.

 

The next step is casting the second part of the form. The box to the top, fill with plaster of Paris and when he Polosatiy, shovel, cut a hole in it — gate. Next, disassemble the form, remove it from the model, its internal surface clean and paint. Now you can replicate the wheels in any quantity.

 

The manufacture of the solution

 

In gipsovke first drink water and then gradually fill up the plaster, stirring the composition with a spatula and gradually bringing it to desired consistency. If the solution thickens, dilute it with water is not recommended, as parts of it are fragile, “unfrozen.”

 

Preparation of mastic

 

The finished product can be easily separated, form or base of the machine before work should be lubricated with stearic mastic with a brush. Stearic chips (you can plane the normal with the cross section) is melted on low fire, to finish there the kerosene and mix; smooth, reminiscent of vaseline, mass. Remember that in the preparation of this mixture, care must be taken, as both components are flammable. 300 g of stearin requires about 1 liter of kerosene.