Trying to match spur gear to worm gear

Hi all, for a project, I want to use some very small stepper motors with worm gears so I can get some decent toque, and the motor cant be back driven. The issue, is that I cant seem to find a small enough worm gear/spur gear set to fit to a small stepper. The stepper motors i'm looking at mostly have a 1.5mm shaft, and the smallest shaft size any of the worm/spur sets come in is 3mm, which is obviously too big. I have bought a small stepper that comes with a small work gear already attached, but I cant tell whether some of the spur gears on Ebay will fit it. :confused:
The motor I have is: this

In typical ebay fashion it doesnt give many specs, only "Worm Gear Diameter: 5mm
Worm Gear Length: 6mm". Which doesnt really seem like enough to find a matching gear. By using my calipers, the pitch on the worm gear looks to be about 1mm, and it has 7 teeth.

I found this worm/spur set on ebay, which looks like the closest I can find. It seems like maybe the spur gear in that set would match with my worm gear on the motor?

If someone knows where I can find small worm gear sets made for 1.5mm motor shafts, I would greatly appreciate it.

Have a look at the Miniature Gears on page 390 of the Squires catalogue

You can buy brass tubing from many model suppliers that should be able to bring the 1.5mm diam up to the 2mm diameter needed for the gears.

...R

Robin2:
Have a look at the Miniature Gears on page 390 of the Squires catalogue

You can buy brass tubing from many model suppliers that should be able to bring the 1.5mm diam up to the 2mm diameter needed for the gears.

...R

Many thanks for the squires catalog link, quite a bit of good stuff in there :). The brass tubing idea is pretty good, I will just need to track down the right size for what I need. Many thanks

I should have said that I have seen the same set of small gears available from other suppliers.

...R

EmanEric:
By using my calipers, the pitch on the worm gear looks to be about 1mm

Measure this as accurately as you can and see if it matches any standard gear module.

If you don't know what a gear's module is: http://fab.cba.mit.edu/classes/863.09/people/cranor/How_to_Make_(Almost)_Anything/David_Cranor/Entries/2009/10/12_Entry_1_files/module.pdf