D1 Camlock Repair

[John CParticipant @johnc47954]

On of the cam locks (pawls?) on the spindle nose of my D1-3 mount has broken. It wasn't me, honest. Searching the internet suggests that these items make hen's teeth look quite plentiful. The favourite solution is a replacement, but failing that, repair. My thoughts are silver solder – what would the members suggest? Judging by the grain structure in the crack the item looks to be cast, and it is hardened. I appreciate silver soldering may alter the hardness, but I probably won't use it enough for that to be a problem.

I had thought of making one, but would struggle with the 5/16 square hole.

Many thanks in advance for your suggestions,

John

[John CParticipant @johnc47954]

[davidkParticipant @davidk]

Hi John

What make is the lathe? For my Boxford 330 for example, they are listed as a spare part, no. X10-02-011. Not cheap at £20.27 each though! See **LINK**

Hope this helps

David

[John CParticipant @johnc47954]

David – inspired thinking! Why didn't I think of that? As you say, not cheap (plus shipping and VAT!) but at least I know where I can get one. It is for a Denford Viceroy 280 Synchro – I shall have to see if they are the same item as the Boxford one.

Many thanks!

John

[Clive FosterParticipant @clivefoster55965]

John

The cam locks are supposed to be standard items regardless of what machine they are fitted to.

If you fancy DIY I have drawings for all the D1-4 and D1-5 components but not, unfortunately, D1-3 although extrapolation down should be possible. Muzzer said in an older thread that he managed to find drawings for the D1-3 via the internet when he made a mount to use his chucks on a rotary table but I've not been able to locate the link.

Perfectly acceptable square sockets can be made by milling a suitable slot and closing the open end with a welded cap. Probably the best method is to make the slot too long and use a "T with a thick crossbar" cap. The stem of the T is made the nominal width of the slot so it can be welded in place across the corner of the new socket with proper penetration on an inspectable weld. The crossbar of the T merely makes it possible to clamp things in place without resorting to a filler piece, which will probably get stuck even if not inadvertently welded (how do I know!). Cut to length when done. Best to do the whole thing a bit oversize and with plenty of material to clean up.

Clive.

[John CParticipant @johnc47954]

Clive – very interesting – thanks. If the locks are standard that makes my quest much easier. I shall look for Muzzer's link.

Thanks again,

John

[charadamParticipant @charadam]

May I suggest Googling for D1-3 Camlock dimensions.

More info than you can shake a stick at.

[MuzzerParticipant @muzzer]

There is a spec for the Camlock dimensions – ISO 702-1 and ISO 702-2 that gives the pukka dimensions. John Stevenson gave me copies which he got from somewhere. If you PM me, I can get you them. I have some of the content in one of my albums here. May be all you actually need. Edit – actually there isn't any dimensional data shown in those pics.

I made a set of these with different features (male hex instead of female square and longer bodies). The actual cam bits weren't too difficult but you need to work carefully and will need a rotary table and mill. You will need to select a hardenable (carbon) steel too. I used 1045 and it came out nicely.

Murray

Edited By Muzzer on 12/11/2017 17:58:57

[John CParticipant @johnc47954]

Thanks Charadam and Muzzer – all good stuff. What are the thoughts on silver soldering the broken bits I have?

Rgds,

John

[JonParticipant @jon]

John i dont think it would last more than two tightenings if at all any.

Strenghening up draw bars and silver soldering dont last long about a month, even mig welding not ideal usually last around 8 months of use daily.

I would sooner buy a part and its hardened. Go by maker of the chuck Elliot or Pratt.

[Clive FosterParticipant @clivefoster55965]

I've successfully welded up similarly broken square sockets several times over the last 20 – 30 years, probably into double figures by now. Not cam locks but chuck adjusters, square spanners and some other things. Far as I know all are still holding up fine. At least none of the ones I did for other folk have come back and I still have two that I did for me about the place. Others went when things were sold / traded on.

Took advice re welding or silver soldering from a usually reliable source before tackling the first one and was emphatically told that silver soldering wouldn't last. Given the heat involved silver soldering is probably not the best idea with a part that should be hard as there is a good chance that the hardening may be disturbed.

My experience suggests that trying to patch the broken bit on is tricky and doesn't always work. Fitting a cap same width as the square then welding sides and base as described in my previous post seems to be most effective method. Can be a total bear to prepare and jig up tho'. Sort of job I try to duck out of these days really.

Clive.

[John CParticipant @johnc47954]

Thanks all for the advice and thoughts. Today I silver soldered the parts together. I fluxed the mating faces and inserted tiny lengths of rod into small cut outs that I had formed using the corner of a diamond wheel. I held the whole lot in a sacrificial spring clamp and heated it. When the rod melted the parts were forced together. So far all seems fine – it is still hard enough to bounce a file off, and has survived several tightenings. But I do know that I can get a new one if this fails!

Thanks again,

John

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