I don’t know how many of you are following this, but I will continue to post progress regardless.
No work on the springer as such, its been away getting welded and still needs a couple of things. Instead I have turned to the brake plate. My original one was too bulky in one particular area , and removing much more material could have left it weak, not to mention looking horrid.
Drum brakes are have a unique requirement when run on a springer - you need to do the axle up tight like normal, but the brake plate still needs to rotate freely with the movement of the rockers.
Figured it would be easier all round to fabricate a new plate in steel, simpler & cleaner looking, probably much much stronger, and I’ll get it chromed along with the forks.
So here goes...
Disc of 6mm steel plate rough cut with the angle grinder, smoothed closer with flap disc.
Disc mounted in lathe - only just fit!! Turn down the OD to be round and clean up the face with some emery cloth.
Centre hole drilled with 1.125” hole saw. Piece of sq tube and a couple of G clamps to hold the disc in place.
Just noticed there’s only 1 return spring fitted.. mustn’t have had any effect on drum operation, it worked fine!!
Sadly the brake arm I whipped up many years ago will be getting replaced with something a bit more suave.
Now for the fun stuff. I machined some mandrels (?) to locate the centre of each brake plate, since I had already drilled a big ‘ol hole in it.
Using some calipers to measure the original distance between axle centre and brake shoe thingiebobs. Surprise surprise, both sides the same!
Transferred onto the new plate
24mm hole for the actuating shaft housing. This done with a step drill, the housing is made from small piece of 1” DOM stepped down to 24mm in the lathe and pressed in. The step provides alignment against the brake plate.
Sorry, skipped a few photo opportunities...
Here’s the shaft housing pressed in, and the fixed post that locates the other side of the brake shoes. Just turned from some 1” solid bar.
This piece is to be welded on the inside, not at all visible from the outside. For alignment, I centre punched the location centre and drilled it out very slightly. When machining the part to be welded, I left a small nub in the centre that locates into divot in the brake plate.
Test assembly, everything looks fine...
These two bits are for the plate centre. It’s 1.250” DOM, stepped down to locate into the 1.125” centre hole. Again this is for alignment. Later a large bronze bush will be machined for this to rotate on. Both pieces are left intentionally long, as once it’s all assembled I can mount the whole thing in the lathe and fine tune the length to get the shoes where they need to be in the drum.
Not ready yet, but this is how everything will be welded. Bolts pulling things up tight and a clamp on the post, will be TIG welded for cleanliness and minimal distortion.
That’ll all I got for today, but cooler weather means much more workshop productivity. I’ve lost so much time with the extreme heat over the summer, but full steam ahead now !