Research and Development

New 15:1 ratio worm and wheel gear box

Following our two previous designs for a small, compact and self contained gear box, we have now come to the third and final stage in the design process. This gear box is shown below in figures 1, 2 and 3.

Figure 1

The above gear box is constructed using a 15:1 gear set which has been specially made for the new design and is housed in a brass casing made in two halves and secured together with two 12BA countersunk screws. This method of construction means that there are no bushes to solder and no etch work to fold-up, leaving only the need for a screw driver to put this gear box together. The use of countersunk screws also means that the head of the screw sits flush to the casing when assembled. This method of construction allows the gear box to be assembled and dis-assembled as required giving the modeller more flexibility when fitting the box. This method also allows the axle to be changed more easily if required.

The approximate dimensions of the box are:

• Width: 0.250" (6.35mm)
• Length: 0.438" (11.11mm)
• Height: 0.365" (9.27mm)
• Nominal centre distance: 0.140" (3.56mm)

The Input/Output shaft sizes on the above box are as follows:

• Input 1.5mm dia. / Output 2.0mm dia.

Figure 2

Figure 3

The partial open frame design of this gear box makes it much easier to produce on a production basis. Production tests are currently underway and we hope to be able to offer this gear box for sale sometime in January 2003.

A drawing showing the basic dimensions of the gear box and an exploded view can be seen by clicking on the drawing icon below

Drawing showing basic dimensions for 15:1 gear box.

We are currently looking at suppling the box in a partially assembled form as shown in figure 1 with the option of either a pin point or plain output shaft/axle. This would leave the modeller, using just a screwdriver to finish the assembly. The estimated cost for the gear box at this time will be between £10.00 and £12.00 per gear box.

If you have any thoughts or comments on the above gear box then please contact us, either by E-mail at enquiries@ultrascale.co.uk or via the Feedback page.

If any one has suggestions for products that they would like to see available, then let us know and we will consider the possibility of adding it to our range.