The Workshop Progress Thread (2017)

This is what happens when a silly old duffer tries to turn a slotted ½" square aluminium rod down to 6mm diameter. I should have expected trouble with this horrible interrupted cut but things have been going well for me recently.

It doesn't jump out from the photo but in addition to the obvious damage the whole square rod is bent by about 10° at the jaws.

This cock-up is the result of a powered 0.5mm deep cut at 2200 rpm with a small ArcEuroTrade carbide insert (the sharp silver type for non-ferrous metals). I noticed the far end of the rod cutting rough due to slight chatter and was wondering what to do about it next time round. Bang - too late! Despite the spectacular bending resulting from the dig in the insert survived. I thought the sharp tip at least would be gone but it's OK.

Lessons learned:

• cut the slot AFTER turning the rod.
• don't dither if something complains whilst cutting.
• carbide is tougher than Aluminium.
• Eek! that could have been a finger.

Dave

Dave

I'm sure most of us have "been there, done that" in some form or another, I know I have. The only thing is that I felt so stupid for not forseeing what was inevitable that I kept it to myself. Thanks for showing your "lesson".

Jim

Hi Jim, IIRC it's called parallax error; no I didn't solder them, the rods were a push fit into the ends & Loctited in which should be tight enough for a air operated display model.

​George.

No one sees what you chuck under the bench. (Unless of course you post a picture)

regards Martin

Hi Jim,

My brother-in-law is an excellent photographer. It's something of an illusion - he achieves quality by secretly destroying any photo that's less than perfect. In practice that's almost all of them! Is he a failure or a success?

When I first started with a lathe in my garage I didn't know what quite what to expect. Judging by what you see at shows, in magazines and on the web, everyone else effortlessly does impressive work. Actually there's a lot to learn! Mistakes are inevitable and are probably far more common than most people admit. Especially if you're self-taught.

I don't want to mislead anybody about my metalworking skills. I'm in the hobby for fun, utility and learning rather than a desire to impress. So I'm happy to share my blunders - errors are very educational. And the fact that they happen is all part of the game.

Perhaps the forum needs a new topic devoted to errors and mistakes. It could be called 'What's the Clown Done Now?' 🙂

Dave

George

I'm sure your cross arms will be fine, mine are and I used Loctite.

Jim

Finished the mechanics of my CNC Myford dividing head. Pinched the design from John Haine who kindly sent his drawings, and will be pinching the elctronics design off Silly Old Duffer, but some other jobs to knock off firts.

I had a delivery from Ringwood metals in the week which includes a 1.0m length of 35mm bar to make a between ctrs boring bar for doing the Otto Langen cylinder so this afternoon I cut it down to 675,, and reduced one end so I can hold it in a 3/4" MT3 collet which will give me the most room between spindle nose and live ctr. This also happened to be about the most I could face off as the carrage and topslide would not move any further to the right.

After a short break while life got in the way of workshop time it was on with Popcorn.

Having completed the parts of the engine I broke it down for painting and looked at the amount of brassware I had decided needed to be polished up. My conclusion was that I needed a buffing wheel! As luck would have it during my "life break" I aquired a domestic Stuart Turner shower pump with a faulty, vastly overcomplicated, switching module but with a very smooth motor. Said motor looked to be just the thing to power a buffing wheel and after a bit of bodging and the addition of a pigtail and buffing wheel and an NVR switch it turned out to be so.

Just some of the shiny bits

Whilst wood butchering for the Buffer I also made the plinth. My first attempt at engine turning on the base looks OK as long as you stand well back, which I recommend when viewing my efforts.

Jim

Hi Jim
Plinth looks good... from here on my screen.

George.

Had another session on my vertical cross engine yesterday... machined up some small bits from brass...

#53... top cover
#59... Stem nut
#60... pipe flange
#65... pipe connector

​Those who have made one will see from their dwgs... still need to finish of drilling etc.

​George.

p.s what method did you use to create the effect, small wire brush, rolled emery cloth, abrasive pad?. I have used various methods to varying effect, just a point of interest.

​George.

Hi George

First off I bought a very low grade drill press off e-bay for £20 specifically for this job and with the intention of selling it again after I'd used it (although I'll probably keep it because after a bit of fettling it's OK for butchering the brown stuff).

Then I made an abrasive tool from a piece steel rod, a piece of 20mm dowel and a pad of soft leather cut from one of Mrs Jim's unused belts (I think it was unused, it will be now!)

After some experiments with fine and coarse valve grinding paste I settled on the fine and, after clamping a fence to the drill table, away I went.

Jim

Edited By Jim Nic on 15/12/2017 12:44:04

Thanks for the info Jim; a similar method to one o many I used previously.

George.

Made some more bits for my vert. cross engine...

Valve body, spindle, still need to thread spindle to mate up with stem nut, drill bottom flange.



​Partially assembled valve configuration ...



​George.