How To: Rubber Combinations

If you fly rubber and find that your motor is either too strong (and you want a slightly weaker motor) or too weak (and you want a slightly stronger motor, maybe you don’t know intuitively what is the next increment.  I encountered this and decided to develop a chart or table to help me.

This assumes two things:  1) you won’t be using a rubber stripper and 2) you have the 5 sizes of rubber available (1/16″, 3/32″, 1/8″, 3/16″. & 1/4″).  With these sizes of rubber, you will be able to combine them into nearly every 1/32″ increment.

The information is arranged in vertical columns.  Find the desired motor in the left-most column.  Then move across that row and each cell in that row offers a combination that creates that total.  Each column has a certain dimension of rubber as the Primary and then what secondary dimensions will need to be added.

The example that started me down this path was a motor that was 2 loops of 3/16″.  I thought it was maybe too strong, but what would be the next smaller size?  With this chart, I can see that 2 loops of 1/8″ plus 1 loop of 3/32″ is the next smaller increment – of one more step would be 1 loop of 3/16″ plus 1 loop of 1/8″.

Increment 1/16″ 3/32″ 1/8″ 3/16″ 1/4″
1/16 1/16
3/32 3/32
1/8 (2x 1/16) 1/8
5/32
3/16 (3x 1/16) (2x 3/32) 1/8+1/16 3/16
7/32 3/32+1/8 1/8+3/32
1/4 (4x 1/16) (2x 3/32)+1/6 (2x 1/8) 3/16+1/16 1/4
9/32 (3x 3/32) 3/16+3/32
5/16 (5x 1/16) (2x 3/32)+1/8 (2x 1/8)+1/16 3/16+1/8 1/4+1/16
11/32 (3x 3/32)+1/6 (2x 1/8)+3/32 1/4+3/32
3/8 (6x 1/16) (4x 3/32) (3x 1/8) (2x 3/16) 1/4+1/8
13/32 (3x 3/32)+1/8
7/16 (7x 1/16) (4x 3/32)+1/6 (3x 1/8)+1/16 (2x 3/16)+1/16 1/4+3/16
15/32 (5x 3/32) (3x 1/8)+3/32 (2x 3/16)+3/32
1/2 (8x 1/16) (4x 3/32)+1/8 (4x 1/8) (2x 3/16)+1/8 (2x 1/4)
17/32 (5x 3/32)+1/6
9/16 (9x 1/16) (6x 3/32) (4x 1/8)+1/16 (3x 3/16) (2x 1/4)+1/16
19/32 (5x 3/32)+1/8 (4x 1/8)+3/32 (2x 1/4)+3/32
5/8 (10x 1/16) (6x 3/32)+1/6 (5x 1/8) (3x 3/16)+1/16 (2x 1/4)+1/8
21/32 (7x 3/32) (3x 3/16)+3/32
11/16 (11x 1/16) (6x 3/32)+1/8 (5x 1/8)+1/16 (3x 3/16)+1/8 (2x 1/4)+3/16
23/32 (7x 3/32)+1/6 (5x 1/8)+3/32
3/4 (12x 1/16) (8x 3/32) (6x 1/8) (4x 3/16) (3x 1/4)

 150 total views,  4 views today