Welding continued

In the example below we are fitting a 3.5" wheel to a mini driveshaft joint in order to act as a road speed sensor. As the driveshaft will be moving in and out as the suspension moves I have used two trigger wheels stacked up to increase the view of the sensor. You will also notice in some of the pictures that the wheel has all 36 teeth in place, this is necessary as the speed sensor I am using isn't interested in the exact position of the wheel so doesn't use a missing tooth. To add the tooth back in to a 36-1 wheel I added a bead of weld where the missing tooth was and shaped that with a dremel.

To demonstrate what can be done with a minimum of tools rather than use a lathe to cut out the hole to the size of the joint I have stitch drilled around the wheel to leave leaving a hole slightly smaller than the joint. The hole was filed clean, still slightly undersized and finally sanded with a drill mounted flap-wheel the last bit, allowing me to fine tune the fitting.

The trigger wheel prior to fitting	Center drilled out and filed to fit

With the wheel centered and fitting nicely it is best to add a slight chamfer to the edges that you are welding, this gives a large contact area for the weld fillet to join with. Check that all your surfaces have perfectly clean and shiny metal to weld to. Now is the time to work out exactly where you want your missing tooth, check this at least twice!

Once everything is aligned clamp the pulley in a vice, ensuring that you have good access to the areas that you'll be welding, once you're happy with your access start pre-heating the pulley. Try to introduce the heat evenly but be careful not to disturb the positioning of your trigger wheel.

A good snug and even fit on the joint	Pre-heating prior to welding

 The minimum amount of weld that I like to use is four 1" long tags, equally spaced. If possible I like to then go around the rest of the pulley in a few more stages, each time adding 1" of weld until there is an even bead of weld with good penetration going all the way around the circumference.

The minimum amount of weld	Good bead of even thickness