Brake bodges

[plj]

Good to have it confirmed, often refer to my somnolent state when it's my sanity I worry about! Don't think it's the MMM forum as haven't found that one yet, I seem to remember it being one of the cars being restored in India but have checked all their posts with no luck. Is the back plate you mention original, i.e. no welding or braze? If I could get hold of an unmolested one I could make up a jig and perhaps some reinforcement as it seems a weak area. Unfortunately I am in East Sussex quite a way from you, but if the backplate is suitable if you let me know the cost and postage I will send you a cheque. Thanks for the offer of a shoe but Toby has a couple, he is not too far away and my wife loves the New Forest.

Regards,

Philip

[Jpallis001]

Hi Philip, I made a basic Jig that helped me to repair my backplates http://www.vintageminor.co.uk/Forum1/ph ... &start=240 . If I was to make it again I think that I would include something in the middle to locate the back plate (perhaps an old hub)

John

[plj]

Thanks John,
That's the post I was looking for, now, why did I think you were in India? I was thinking of incorporating a plate in the jig with studs to locate in the mounting holes as that area seems the only flat part of the backplate, should then be able to use that as a datum to get both parts the same height before welding.

Regards,

Philip

[garagiste]

What diameter back plate? Let me know and will see what is lurking in my spares.

[plj]

Car is 1931 £100 minor. 8 inch brakes, backplate 9.75 inches overall diameter.

[garagiste]

Philip,

Sorry, checking the boxes lurking at the back of the garage the spare backplate I have is a 9" from early M type/ohc minor.

David.

[plj]

David,
Thanks for looking. I still have one more to remove from my car which seems unmolested but hard to be sure until it's off.

Philip

[Ian Grace]

Just a thought Philip, but if you end up going down the route of making a jig to set up the backplates for aligning and brazing the bushes, it might be worth considering to offer use of it to others in the Register, and the Register would be happy to chip in towards the cost of manufacture of the jig. It could perhaps be positioned with someone with suitable skills who could do the aligning and brazing such that members could send their backplates for overhaul. Perhaps someone like Ian Harris or Mike Dowley?

[plj]

I have considered producing something of a more permanent nature as it seems a pity to put in much effort for just four backplates.
The problem is in ensuring the prototype jig is accurate enough to make it worthwhile, unless my remaining backplate is unsullied (I will remove it tomorrow) the calculations will have to be done from damaged and bodged, sorry ,professionally repaired , parts, not impossible but difficult.
Being long retired I have little professional equipment left apart from O/A & MIG welding gear plus normal verniers and mics, what I would give for a good lathe and milling machine!
Apart from the angle of the bushes there is also the depth of protrusion from the backplate, quite difficult as the backplate itself is not flat (or at least mine aren't), both of these dimensions obviously have a great effect on brake efficiency controlling lining contact and cam operation.
Fortunately I have a friend with a specialist engineering workshop who is sympathetic and tolerant to my odd requests, his latest project is a 4/w/d mini with mid mounted cosworth engine, and he might be persuaded to help.
On another matter, can't be bothered to change threads, s.v. chassis 12765 & 13261 seem to share the same Reg. No KJ 4483!! I really must take up crosswords instead!!

[plj]

Further to my post on Jan 17th when I enquired why brazing of the back plate bush housings was so popular and whether it had any, to me unseen, advantages over mig welding, I was met with a massive non-response. However whilst looking over the first draft of John Nagles excellent revision of the M.R. Minor manual I noted the following quotes from 60's Minor guru John Ridley on repair of backplates :- "The backplate bush housings which have become loose can be arc welded but it must be electric weld and NOT gas welding or brazing. Arc welding gives intense but local heat so avoiding bad distortion of the back plate". He then goes on to say that, "owners must be warned that it is quite impossible to be sure that the housings after welding are in their exactly correct position".
Well, I hope to prove him wrong. I have been fortunate in obtaining a couple of backplates from Toby which, whilst too corroded for use are original and unmolested, with the aid of these I have designed a robust, and rather inelegant, jig to hold the parts in correct position in all three planes to enable repair by Mig welding. The only problem I forsee is that the welding process may set up stresses in the flimsy back plate which could then distort when removed from the jig but we will face that problem if it happens.
Pictures of jig by Wednesday,I hope!!

Regards,

Philip

[plj]

Now I didn't specify which Wednesday did I? Much water under many bridges, but, hopefully pics of jig Mk 4, and repaired backplates by a "soon to be specified" Wednesday.
If there is anyone in the Sussex area who is prepared to help with the restoration of the frame and tinwork, yes I will pay, of my early s.v. Minor please contact 07977907009.

Regards,

[plj]

Now have jig Mk 5 and it seems to work. Brake repairs now under way, as I am attempting to make TF 4293 roadworthy for this centenary season I will continue on an Our Cars posting.

Regards,
Philip

[plj]

Is there some trick to make these pics of a viewable size?

Regards,

Philip

[Ian Grace]

Is there some trick to make these pics of a viewable size?

Regards,

Philip

Yes! Either re-size them to 900 pixels wide - OR just e-mail them to me and i can re-size and upload. The advantage of the latter is that the images will forever reside on our website, so will never disappear, as they might if uploaded to Photobucket, Dropbox, etc.

And congrats on this fine piece of enginnering, and good luck with returning TF to the road this year.