Member postings for Dave S

After a bit of a gap, and a workshop re arrange I have my little CNC in a place where I can get to it, and will probably want to use it. This is my plan to actually make use of it.

I am usign Fusion360 for the CAD/CAM - I know the personal use thing is restictive, btu Ive tried and I just cant get on with FreeCAD at the moment. I need to learn so many things that adding a new CAD interface is one thing to many.

Anyway, ramble over:

I am trying to understand how to model the clamps/ vice / other things that I need to have around the stock, but do not want to bump into with the cutter.

I think I model them as extra bodies in the positions they will be, but shoudl they be components?

Any tips gratefully received.

Dave

Edited By Dave S on 09/12/2021 18:25:13

Ah. Good clarification

Mine came without table guards, so I cobbled together something that mostly contains the mess.

Did read like put a big wheel on it, take of the guard if it won’t fit…

Dave

Shouldn’t need to spin a big wheel. That photo is a used 180mm wheel - It measures about 170mm diameter and the wheel head wasn’t at the bottom of its travel

removing wheel guards is a thing to only be done after careful consideration IMO

Dave

My wheel will touch the table - are you sure the way covers on the column are not sticking?

On my table there is a raised area of the t slots- not by much maybe an 1/8” which is clearly designed to be ground in. Do you have a similar patch?

pic shows wheel on table and the raised pad:

Dave

Edited By Dave S on 07/12/2021 18:18:21

Mine is around 1960 judging by the build plate on the oil tank.

Some photos here **LINK**

Dave

Taper pins on my controls, presumably so you can’t put them on 180 degrees out.

Don’t know if a roll pin in a taper hole would form itself into a taper?

Dave

IIRC it’s a taper pin. So will only come out one side.

I can have a look tonight - mine was off not very long ago.

Dave

CuP alloys sell pastes.

never bought from them, but they do pop up on here with useful advice form time to time, so may well be along presently

Dave

Awesome work.
Any chance of a photo with a rule in it so we can get a true sense of the small scale?

Dave

Deep fat fryer with ordinary cooking oil will do 200 degrees quite nicely, which is low end of tempering.

Dave

For bores I use the sliding T gages and then measure those with a mic. Seems to work well in my experience.

I have 'reworked' the gages slightly to make them smoothly operating - This Old Tony has done a video which is basically what I did.

Dave

You don’t say what lathe you have but I used carbide successfully on my L5 before I got my CVA.

I use CNMG inserts for general turning and ccmt06 for boring. There is a good chance you can use negative rake inserts just fine - 11” lathes are not generally wimpy bits of CI. Negative rakes inserts of course have more corners per insert so can work out cheaper.

I machined down my general holders - bought the cheapest size so my rh tool is a 25 and the left is a 20, but both have been machined down

I still use HSS for turning, usually for form tools like threading.

Dave

Having tools that are capable of measuring to 1 micron and actually measureing to 1 micron are two very different things. (I used to work in a metrology research company)
If you look at the typical spec sheets for mitutoyo mics then they might have a 1 micron resolution, but they have an accuracy of +-2 microns...
Only the *really* expensive ones are any better.

I am under no illusion that I will actually be able to measure to a micron, but the old metroloy adage is to have tools that are at least 10x more capable than the accuracy you want.
So for 0.01mm you really want a 0.001mm tool.
Thats why I originally bought 1/10000" micrometers.

Just occasionally when I hold my tongue just so I manage to hit the number I was after dead on.
That feeling when a bearing slides into a bore with no shake, or the piston makes a bouncy airtight seal is great, and even more so when you did it to measurements rather than sneak up on it fits.

Dave

My lathe (CVA) has an Anilam DRO fitted.

The cross silde scale is fine, but the bed scale has packed up.

It seems cheaper to buy a complete DRO than a single Anilam scale!

Is it likely that an amazon (for want of a better reference) scale will just work with my exisitng DRO unit? I think I should probably think about replacing the cross slide scale at the same time as they are the same age, so sods law says it will die soon.

The scales are 5 micron resolution I think.

Dave

the pot is £500, but I also want to fix the lathe DRO in that - about to post a seperate thread about those.

Not sure how much the micrometer will get - but inspite of most of my machines being 'native' imperial the mill and lathe have DRO's which are almost always set to metric.

I have 3 sets of verynears, 1 traditional stainless one and a pair of lidl/aldi/soemwhere else cheap digitals. The digitals seem to always have flat batteries - hence wondering about battery powered micrometers...

I do as it happens have an old Mitutoyo 0.001mm digital micrometer head from an optical stage, but that takes 3 AA batteries and is the size of a stepper motor.

Dave

I have some toy money and I am lacking in metric measurement tools.

I have 1/10000” reading mitutoyo 1” and 2” traditional mics and a set of gage blocks ( mics and blocks check out with each other and the mic standard which came with the 2&rdquo

I am considering adding new shiny 25mm mic - especially as I have recently added a metric tool grinder, so it will save a bit of 25.4 calculating.

Do I add the matching old skool mitutoyo, a cheap old skool mic, or go digital - and if so is there good reason to go for a mitutoyo or other make?
I think ideally I might want to also add a depth mic - I use the verynear calliper for depths currently.

Thoughts please.

Dave

Using allowable engineering approximation:

area of square t nut 576, area of slot 360, so area in contact 216mm square

Area of circle 452, area of slot approx 360, so area in contact with circle approx 92.

Or under half…

Dave

From memory I bought some thin ceramic lagging from Reeves or one of the other normal suppliers. It’s about 2mm thick. I used the supplied boiler bands, but I think I had to use slightly longer bolts to join them.
I only clad the sticking out part - the bit in the “firebox” is left as is and so I don’t think the cladding needs to be super heatproof - at 15psi the steam temp is not much above boiling water, so by inference the boiler shell can’t be either. Prior to lagging I had just painted with etch primer and enamel, but trying to run it outside was dependent on it being a warm, still day.

I used bike pot black engine paint for the firebox area, with dark green on the driving position/ tender - just a masked line straight down from where the levers attach.

Just looked and the enamel I used was Plasti-kote projekt paint fast dry enamel. Came from Wilkos for 1.99 something like 10 or 15 years ago!

Dave

The Mercer is a “pot boiler” type of boiler, and certainly mine is made from brass.
I insulated it and clad it with thin shim steel - which is then straightforward to paint. Also made a huge difference to the steaming - as the flame is under one end and the boiler stick out is exposed to the ambient air.

For what it’s worth mine was primed with Craftmaster etch primer, then top coats were enamel iirc.
That was quite a while ago, when John at Minsteam was still working with Phil at Craftmaster.

John doesn’t do technology, but I’m sure Sarah will respond to an email asking what they currently use.

Dave

Mine has a SHCS in it. Was like that when I got it…

Dave