Machining the Smokebox saddle

[Paul Ivinson]

Although I haven't posted for some time progress on the Simplex chassis is pretty much complete.

The next job is to machine the smokebox saddle. It looks simple at first but what a horror to hold. The outside surfaces aren't too bad but
does anybody have advice machining the 2 1/2 in radius saddle itself?

My Boxford doesn't have enough swing to mount on the faceplate. Has anybody tried mounting on an angle plate and machining on a vertical mill?

Paul

[lancelot]

Hello Paul,
just wondering if it could be mounted on the cross slide
and flycut using a between centres boring bar, should get you an effective radius ok. [most tool holders on cross slides are removable to allow for this practice.] it can be held down on slide with slot clamps as used in milling.
All the best for now,
John.

[Paul Ivinson]

John,

Thanks - good suggestion but in this case there isn't enough clearance between the cross slide and the centre height of the lathe.

This job looks as though it ought to be simple but I keep hitting snags.

I haven't got a boring head for my vertical mill but I think I need to buy one.

Paul

[GeorgeRay]

Do you have a vertical slide for the Boxford that you could bolt the saddle to and then fly cut verticaly instead of horizontally if you see what I mean. It could of course be bolted to an angle plate on the cross slide providing you get the centre of the saddle at the centre height of the lathe.

[ron]

Hi Paul
Haven't made mine for the Simplex yet so I'll be interested in how you get on. On a Tich one I did I ended up doing it the hard way, ie with a file but it's a good bit smaller than the Simplex one.
Ron

[Steve M. W]

Hi Paul

I did my Simplex saddle in the VM with a fly cutter, From memory i used an angle plate as a stop for the base to rest againstthen packed it of the table and clamped it. It took alot of time to set up and get the cuter at the right rad and center to the casting. A mate at night school showed me how to set the fly cutter to the radius useing the lathe and the top slide that bit was quick and accurate.

Steve

[Steve M. W]

Sorry try this version without the typos

Hi Paul

I did my Simplex saddle in the VM with a fly cutter, from memory I used an angle plate as a stop for the base to rest against then packed it of the table and clamped it. It took a lot of time to set up and get the cuter at the right radius and centre to the casting. A mate at night school showed me how to set the fly cutter to the radius using the lathe and the top slide that bit was quick and accurate

Steve

[Paul Ivinson]

Thanks for all the suggestions.

I machined the base of the casting last night. This morning I ordered a fly cutter. The VM is only 18 months old and I'm still tooling it up. Thanks for the tip about using the lathe to set the radius - I ordered a straight shank fly cutter to allow me to grip in the 3 jaw and a ER32 collet in the VM.

[drjohn]

Although it's half a year since the thread was started, I thought I might add my tuppenceworth for those (like me) not brave enough or well equipped with sufficent machinery, who shy off from flycutting the saddle.

I made this 5" diameter drum from old bits of wood nailed together and put a bolt through the middle with a centre pip for the rotating tailstock centre. I cut a slot and poked in some linisher belt 120 grit, wrapped it round against the direction of rotation and stuck the end with double-sided sticky tape.

Holding the saddle against it by hand with the lathe spinning at whatever speed you fancy, gives a splendid finish - but beware, it can remove a LOT of material! Regular checking and measuring so that the pressure can be applied on the appropriate bits to keep it true. Also works for the chimney base and with the drum reduced a little, for the underside of the dome.

On the lathe bed are smaller versions for use in the drill press for smoothing out corners on coupling rods etc - the sanding stuff is just held with rubber bands on those, and as the outer layer wears, just unroll and cut it off.

Cheap and cheerful.

[Shawki Shlemon]

When there is a will there is a way . Good on you , well done . It is a great satisfaction to do a job with the minimum equipment .

[lancelot]

Next to the mill and the lathe...some of the most useful equiptment I know...the linisher, flap wheels, sanding drums and emery tape...
John.

[baggo]

When machining the saddle for Helen Longish I used a between centre boring bar with the saddle soft soldered to a piece of brass which was then bolted to a vertical slide mounted on the cross-slide. The diameter was only 3-3/8" so the centre height was no problem (ML7) but this may not be so easy for the Simplex.


John

[Shawki Shlemon]

This is similar how I bore my cylinders between centres , see my thread on this topic with pictures . The lathe is an amazing machine .

[drjohn]

That's impressive, John (baggo) - I wouldn't have had the guts to rely on soft solder.

I presume you used what I would call "plumber's solder" - the bars of solder you can buy from hardware shops in the west (but not in Malaysia!).

What did you use for a flux, as it seems to have let the solder run well?

As you can see on my website, I silver soldered the chimney to a bit of angle iron for machining, but the high temperatures seemed to create an impenetrable skin on the gun metal - obviously, soft soldering doesn't need that sort of heating.

I'd be interested in the details - might even try to source a vertical slide - but like everything else of use to model engineers here, that will probably be like hen's teeth!

[baggo]

Hi Drjohn,

I actually used ordinary multicore solder as used for electronic work but used Bakers Fluid as well to ensure a good joint. The base of the saddle had already been machined flat and the area of the soldered joint was quite large in total so it's pretty strong - fine so long as you take light cuts! I use soft solder to hold parts together for machining a lot. For example I needed to make a pair of bogie equalising beams from flat brass bar so I soldered two pieces of bar together, machined them as one, and then seperated them afterwards.

As mentioned earlier by George, you could bolt the saddle to an angle plate instead of a vertical slide - more fiddly to set up but probably a lot easier to get hold of!

John

[drjohn]

Hi John

I was reviewing the possibilities today, and I'd need an incredibly hefty vertical slide or angle plate - the centre on my strange Chinese lathe/mill is 8" above the bed so the top of the saddle for Simplex would be 10 1/2" up in the air - I think I'll just stick to my sanding drum technique pro-tem, but the soft solder idea will be useful for lots of other little tasks I'm sure.

[steam4ian]

G'day John.
I'm surprised you are having trouble getting plumbers solder in Malaysia. I was in Kuching Sarawak this last August and delighted to see the tin smiths were still working in shop houses in a lane (lorong) between the Bazaar and Jalan Carpenter. They had sticks of solder.
I first noted that the tin smiths were there during my first business visit in 1994 and I hadn't returned since 1997. They have the simplest of tools but turn out the most intricate shapes; I could watch for hours. I think one of the places had closed but two are still in operation.

On this last trip my wife and I went on tour of Malacca and were taken to what was called "Blacksmith Street" in the Chinese quarter. I searched the street and found three operating forges. One guy was sharpening the tips of rock breaking drills.

I love hardware shops in Kuching, there does not seem to be anything you can't get. Didn't have any success getting a rotary table! I couldn't see where the trade/industrial section of KL was located; it is probably in the Klang Valley.

Regards,
Ian

[drjohn]

Hi Ian,

As you say, you found some aspects of Malaysia I have yet to discover (although I've been here almost 9 years!), but I did manage to get a 6" Chinese rotary table for equivalent of about 70 quid British. You can see it in the workshop section on my website.

At present I'm trying to source a couple of kilos of washing soda for electrolytic de-rusting of the frames before I paint them - I can get a 50 kilo sack no problem, but so far haven't found smaller quantities. Big stuff is easy to get here, but the smaller stuff is not so available.

If you're ever back in the KL area, pm me before you come and maybe we could meet up.

DJ

[steam4ian]

G'day John.

Thanks for your reply. I enjoyed your web site, particularly the outdoor welding! Great protective gear, lucky you didn't get a drop of slag between your toes. The support frame for the simplex chassis was most informative.

Don't know when I will get back to Malaysia. My wife and I love the country and the people. We were there a week before Merdeka and the national pride was tangible; made us proud to be there. Our friends Kuching certainly want us to return. I was involved in a project there some years back.

Regards,
Ian

[drjohn]

It's nice, Ian to find someone else who has a vague understanding of this TWC (third world country)!

Back to a Simplex note as this thread is supposed to be about that !.... Just been pulling myself up today.

I did a complete strip-down for frame painting, and as I was ashamed at my feeble attempts at pinning the return cranks onto the crank pins, I decided to take them off and start again as the taper pins had virtually broken through the squint holes I'd drilled by hand.

Just as well... when I gently tapped the taper pins, they virtually fell out, then the return cranks rotated easily by hand.

So I then had the task of removing the crank pins from the driven wheels! WOW!

I heated the crank pins to blue and beyond, trying not to damage the paint on the wheels. Then ground a flat on a ball bearing, super-glued it to the inside of the crank pin, made a tube to accommodate the crank pin, and put the whole caboosh in the vice.

Having shed 15 kilos with my newly-found diabetic diet, obviously my leverage on the vice was insufficient, so, adding a bit of 2 foot tube and closing my eyes to get the extra quarter turn, I was woken by the gunshot of the loctite releasing. I was so relieved that I let the whole wheel/axle assemby fall 3 feet onto the concrete floor. Much to my surprise, nothing broke. Same with the other one. However, something has misaligned with the 3 foot fall onto the concrete as one wheel now has a 10 thou wobble. But after all, this is just a Simplex, so what the hell - I'm not going to pull the wheels and re-quarter them to match the other 4!

So now, when I get more silver steel from the UK (yet another thing I haven't sourced in Malaysia), I will make new crank pins and go from there.