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bezaboy

Jig for machining brake shoes

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How do people machine brake shoes to fit a drum brake for full surface contact ? Pictures of any jigs ?

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remove lip off drum (if any) dremel /die grinder /file

assemble oversize shoes on brake plate

find / make nut and bolt to go through spindle hole (nice sliding fit) fit to chuck

I use tailstock to apply pressure to bolt ( belt and braces )

important bit..  fit two pieces of hacksaw blade between cam and shoe , to give running clearance

high speed , sharp bit , turn down, removing and replacing  until it is a nice sliding fit in drum, keep going a bit at a time till this is achieved.

I like to leave the leading edges unfeathered , theory is that it will scrape the mud etc. off,  but if it starts to grab in use I put a small taper on , increasing size till grabbing stops

 

That's how I do it.... 

 

( remove hacksaw blades before use , but leave them in for fitting!!)

   

 

 

 

 

Edited by moleman
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Same as moleman except I machine the drum surface with a lathe.

My "jig" is a piece of steel rod that is a neat fit in the backing plate hole and with a male thread cut on one end so I can pull the backing plate against the chuck jaws with a nut.

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AS above except I use the axle in the chuck and a tube that slides over it between the chuck and the face plate.

The axle is in the jaws and the "head" end has a center in it that the tail stock goes in. Used the tail stock to apply clamping force (not much),

nipped up the final bit on the chuck, machined it quite slow with very slow feed on the carrage.

pick which one suits and enjoy.

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I mount my shoes on the backing plate with a thin spacer each side of the cam as suggested above, clamp up in the chuck using the wheel spindle and nut (spindle clamped in the chuck and then the nut is used to simply clamp the back plate to the front of the chuck)

I machine very slow and take small cuts, thats a lot of mess to be made if something digs in, in fact I have put the gearbox in neutral and turned the chuck by hand but that is hard work !

Very effective result though so worth the effort

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I have mounted the shoes up on the brake plate as already suggested,but rather than packing the shoes out I use a cable tie hooked onto the brake arm back to the torque arm bolt.This way I can adjust pretty much exactly how far I want the cam to turn to get the right O/D Works well, abut 250 rpm and a sharp tool,very light feed.

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15 minutes ago, nigel dabster said:

how do you get "oversize" shoes?

Companies like Villiers Services or Saftek will fit thicker lining material to bare shoes if you request it over the standard lining thickness.

Edited by jon v8

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Hi I get my shoes reclined at Friction Services just outside Keynsham nr Bath. Specify the soft trials material and the thickness you want. Quick service and about £15 a wheel set of shoes. They will machine them for you but to be honest I tried it once and was not pleased with the result. To machine the shoes I have an aluminium bar about 2" dia clamped in my 3 jaw chuck with a spigot machined to fit the backplate. Push on the assembled backplate and pressure drive it with a revolving centre in the tail stock.

to machine them I clamp a 8" long bar in the tool holder and with 2 tie wraps clamp my Dremel die grinder to it. A grinding wheel in the dremel and away you go. Much less chance of picking up than by using a normal lathe tool. 

Hope this helps.

Edited by auster
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Send your old worn shoes to Villiers services together with an accurate measurement of your brake hub internal diameter and they will fit a thicker lining to accomodate, I think they will in fact do the job for you and they have a choice of friction material. Best to contact them and discuss

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Seen on Land Rover forum.

Glue rough sand paper to inside of drum with spray on adhesive. rub shoes along sand paper. Remove sand paper and wipe of glue with thinners.

whitehillbilly

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