The Worden T&C grinder

Back in 2012, I purchased the plans and construction notes for the Worden tool and cutter grinder from Hemingway kits. At the time, we were living in France and I decided against purchasing the kit of parts, mainly due to the freight costs. Now that we are back in the UK, I have ordered a kit and anxiously await its arrival. Whilst waiting, I have been re-appraising the drawings and evaluating the possibility of converting to all-metric, both dimensionally and fastener-wise. Hemingway have partially gone down this route but have stopped short of complete metrication. (Apparently a lot of their customers still prefer to work in imperial measurements.) Nevertheless, I want to go metric if I possibly can. Having looked carefully at the drawings, I was amazed to find that, in addition to the (already changed) metric fasteners, there was a call for six different thread types and/or sizes, not to mention the need for a ¾ inch reamer for the slider block. I investigated the cost of one of these from my local engineering suppliers and was shocked to find it was the thick end of £100! I had to find an alternative. Most of the thread sizes can be quite easily swapped for metric, for example, M5 for 2BA, M3 for 6BA and M3.5 for 4BA (at a pinch). Some of these are slightly oversize and as a consequence don't leave much "meat" around them. This I can undoubtedly get around. My main concern is the ¾ inch diameter sliding bar and its associated block, which I am stuck with, unless I replace it with 20mm Ø ground stock . I have in mind boring the block to 20mm and making two bronze or brass bushes, each 25mm long pressed into a counter-bored recess at each end of the block. I appreciate that not many of the membership will have built the Worden and so will possibly not know what I'm on about ( a not infrequent occurrence!), but for those who have, what do you think of my proposal?

If anyone has already made the conversion to all-metric, I'd be pleased to hear from them. If only to stop me a) making any mistakes and b) re-inventing the round rolling thing.

Sorry for the long-winded preamble. I got there eventually.

John

I built a Worden as is from the kit, the 3/4 hole in the CI block, I dont think you will gain anything by the inserts. It is easily bored out but if you want to borrow a 3/4 reamer I have one.

One of the main problems is that the angle settings of the table are not too clever. Think of a longer pointer to make it more accurate.. I set 'zero' by using a square against the face of the wheel.

The table itself is a stamping and I used an ordinary wood sander (Flat plate) to go over it to remove burrs and it gives a nice mottled finish. Also make a jig to hold a Stamp for marking the degrees around the table.This having a pivot to make sure numbers are all in line.

I made mine on an ML10 but only just. Make lots of collets and blocks for holding tooling, you will need them.

Clive

I have toyed with the idea of building one for some time and I'm sure that it could be an interesting project ...........but £400 (ish) + extra tooling etc. is a lot of cutters!

Norman

Edited By NJH on 16/10/2016 11:05:14

Clive,

Thanks for the feedback. I'll certainly try boring the through hole first. I can always open it out and fit the bushes if I mess it up! Thanks also for the offer of the loan of the reamer; I'll bear that in mind. I've decided to stick with the imperial sliding bar and bock but try to metricate the rest of it.

Norman,

I hear what you say and agree with your argument over the cost but the idea is that the enjoyment (I hope) of building the kit will be at least half the purpose of buying it. I've ordered the drilling grinding jig as well, so I can dig out all those blunt and badly ground drills I've got and give them a new lease of life.

John

Thanks John - I agree your justification is quite sufficient! I suppose that we could argue that no "model" is necessary - just think of the cost of making, say, a 5" g loco but lots of folk get pleasure from making and operating them . ........Well I think I had better look again at the Worden and maybe that could be a project for next year!

Norman

I built a worden many years ago, if I recall correctly, I drilled the slide block a shade under 3/4" and then bored to fit with a very sharp has boring bar to fit, no real need to ream if your lathe bores truly parallel

I threaded everything metric as at the time I didn't have any imperial taps and dies.

I have to agree that the angle setting is less than ideal, I usually set angles using a digital angle gauge on the table.

One modification I have made which I think significantly improves the machine is to mount the motor on a hight adjustable pillar as, with the table at an angle for some operations, the work piece is not on the wheel centre line

19mm is only a gnats cock under 3/4" and you can buy 19mm silver steel

I made one from bits and pieces at the Model Engineering class about 25 years ago. I later sold it when space in the workshop became a problem. Regarding the reamer, why not take the bits to your local machine shop, they will do it for you, or if there is a Model Engineering club close by get in contact with them, as I'm sure a member will have a 3/4" reamer or know some one who has. As Clive has already said, make a jig for the number punches, nothing looks worse than screw wiff numbers, spoils a good job. john

I think it is an excellent idea - wish I'd thought of it. When I made my Worden I bored the slide block between centres which ensures that the hole is parallel but these are tricky things to adjust for exact sizes and I had to scrap my first attempt. Your method easily overcomes this problem. I think the sleeves could be only 12 mm or so deep and still be fully functional.

Go for it,

Rod

Thanks, everybody. All comments and suggestions are noted. When I get the box of bits, I'll have to start making some decisions. At the moment it's all floating round in my brain and bouncing off the sides. A couple of minor projects to complete before I can start ruining metal, but I'll get there in the end.

Regards,
John

John,

My Worden which I bought second hand has a 'loose' fit on the block to the 3/4" shaft.

I had the same idea as you but using commercially bought in oilite style bushes on 20mm shafting - and replacing the block with something slightly larger if necessary. However my aim is to have a functioning Worden rather than enjoy making it!

Regards,

Simon

When I built my Wardon (now sold) I bored the block over size and fitted PTFE bushes of this type **LINK**

On a drill grinding machine I've recently built I used linear motion ball bearing slide bushes of this type :-**LINK**

with excellent results..

Ian

Simon and Ian,

Thank you for the responses and ideas. All useful information, if not for this project, then for the future.

I've made a start on the conversion to all metric ( in CAD ). When the kit arrives, I need to make some accurate measurements to ensure it'll work.

John