What Did You Do Today (2016)

[John Stevenson 1Participant @johnstevenson1]

On Saturday I got a phone call from the scrapyard to say they had two tubs of carbide come in and come asap on Monday as it would be out the door pronto as the prices fluctuate so much on Carbide.

Currently running about £8.20 a kg.

So decided to kill two birds with one stone and even though I have repeated advertised loads of free steel on here and other sites I have finished up with about 5 callers who collected some. It's time now to start clearing up so on Sunday i loaded slightly short of one metric tonne into the Donald and ran it down the yard this morning. Shame but obviously the weld on the armchairs is too strong. Still made £103 for the toy fund.

Then went to sort the carbide.

Those tubs are about 15" x 10" x 10" and weighbridge price was £700 [ seven hundred ]

A lot was 16mm shanked up to 20mm but mainly 16mm. I can use this OK but the problem is as it's sold on weigh you are buying a lot of shank so decided to keep to 10mm and under.

Part of my haul can be seen on the right. Finished up filling a 5" high coffee cup as [a] getting loads of useful cutters and [b] keeping the price down.

Sorted.

72 cutters in total with about 90% of them fine as these have come out of an aerospace works where they change the cutters on a time basis. But even so if these wanted a lick up it's a decent nights work.

Stuck them on the scales on the way to the office and 3.8kg so £32 at cost £40 retail ??

Showed the boss what I had and he told me to clear off, Bummer, could have got some bigger ones.

Back down there again tomorrow with another short tonne of steel but this is all profile bits and scrap plus he also owes me for the old Fork truck which they took away last week.

Might be able to afford a bit of beef at Christmas this year. ???

[BazyleParticipant @bazyle]

"even though I have repeated advertised loads of free steel on here and other sites "

It was a very generous offer John, just a pity you don't live south of the Watford Gap. Perhaps if you have another load of good steel the Nottingham Model Engineering club would offer to match the scrap price. Certainly our club would like a source like that nearer home for the club exhibition shop.

[Clive HaynesParticipant @clivehaynes74488]

It's gone very quiet on here, must be Christmas.

[Nick_GParticipant @nick_g]

Posted by Clive Haynes on 22/12/2016 17:32:09:

It's gone very quiet on here, must be Christmas.

.

Which means its nearly time for a new 2017 thread.

Nick

[HopperParticipant @hopper]

Went to the hardware shop to buy a piece of 22mm OD steel tube to hang a ceiling fan down from the apex of the shed roof for summer cooling. "You need aluminium tubing, so it does not conduct electricity, mate" the hardware shop bloke informed me. I was too gobsmacked to even manage a reply.

[Anonymous]

I made a ½" BSP adaptor for the dead weight tester, and my first Bourdon tube. I filled the tester with ISO32 hydraulic oil and with enough weight got the end of the tube to move 3mm or so:

There's a slight snag in that the weights shown equate to 2400psi, which is tad higher than my traction engines will be operating. Still, it's a start, and as a plus I didn't get hydraulic oil all over the kitchen.

Next I need to get a calibrated pressure gauge to check what pressures the tester is actually generating. And then think about making a Bourdon tube with thinner wall thickness, and thinner section so that it is more sensitive.

Andrew

[duncan webster 1Participant @duncanwebster1]

Surely a dead weight tester is used to calibrate pressure gauges, not the other way round. If you measure the ram (micrometer) and accurately weight the piston and test weights, you have all you need, even accurately measure the weights, work out the volume and multiply by the density.

I suppose if you are super critical you might want to allow for local variations in g, the acceleration due to gravity, but that might be getting silly

Kozo Hiraoka goes into making preeure gauges in his book on the Heisler

Edited By duncan webster on 24/12/2016 21:25:39

[Anonymous]

Posted by duncan webster on 24/12/2016 21:25:03:

Surely a dead weight tester is used to calibrate pressure gauges, not the other way round. If you measure the ram (micrometer) and accurately weight the piston and test weights, you have all you need, even accurately measure the weights, work out the volume and multiply by the density.

I suppose if you are super critical you might want to allow for local variations in g, the acceleration due to gravity, but that might be getting silly

Oddly enough I'm well aware of that. I'm well ahead of you on the calculations, I've done all that and I did take local gravity into account. However, the tester is old and secondhand, and I have no instruction manual. So before I waste a lot of time making Bourdon gauges a rough sanity check against a known good pressure gauge seems sensible; if only to check I'm using the tester correctly.

[Neil WyattModerator @neilwyatt]

Only 106 pages of posts – this thread has been quiet in 2016!

Well today I welded a bracket back on to an Ikea sofa bed (its doing extra duty over the holidays!) It looks like originally one bead totally failed to take on the tube the bracket fits in so the other side took all the load and failed trough fatigue. They would surely change it, but it was a fifteen-minute job to weld it up. Acrylic paint dries fast on a warm weld

Downside is it reminded me to give my steplad his auto-darkening helmet back

Neil

[BazyleParticipant @bazyle]

Started on foundation piers for a new Men-in-Sheds building having at last got planning permission last week. Over a ton of concrete used so we don't have enough ballast to do all the remaining piers tomorrow and builders merchant not open 'till next year.

[Sam Longley 1Participant @samlongley1]

Posted by Neil Wyatt on 27/12/2016 12:49:11:

Only 106 pages of posts – this thread has been quiet in 2016!

Well today I welded a bracket back on to an Ikea sofa bed (its doing extra duty over the holidays!) It looks like originally one bead totally failed to take on the tube the bracket fits in so the other side took all the load and failed trough fatigue. They would surely change it, but it was a fifteen-minute job to weld it up. Acrylic paint dries fast on a warm weld

Downside is it reminded me to give my steplad his auto-darkening helmet back

Neil

You should be so lucky

Or is it just once a year ??

Uniforms to !!! Oh well if it is only once a year I suppose we can let it pass but the mind does boggle !!!!

[BazyleParticipant @bazyle]

We completed all 16 piers today. 2 1/2 tons of concrete, equivalent in hardcore and a fair bit of soil dug out. Dog didn't understand these humans digging holes then filling them without putting a bone in first. Here's a reminder of what it's about. perhaps you can help in your area.

[Peter KroghParticipant @peterkrogh76576]

I just watched the video in the link, Bazyle. I must say that you have an excellent program going there.

Congratulations to all.

Pete

[Anonymous]

I've been hogging out a bracket from hot rolled steel to hold the CNC mill high speed spindle:

And here it is installed on the CNC mill, complete with a 1mm ballnose cutter:

Andrew

[John HaineParticipant @johnhaine32865]

I suppose if you are super critical you might want to allow for local variations in g, the acceleration due to gravity, but that might be getting silly

Oddly enough I'm well aware of that. I'm well ahead of you on the calculations, I've done all that and I did take local gravity into account.

Just as a matter of interest, how did you measure it?

[Bob RodgersonParticipant @bobrodgerson97362]

Hi Andrew,

I did a similar thing with my Tormach to take a Kress spindle. I haven't used it yet but once I get Gearotic to work for me I will give it a try at making some bevel gears using very small cutters. Presumably that is what you intend to use it for.

[Anonymous]

Posted by John Haine on 29/12/2016 12:23:01

Just as a matter of interest, how did you measure it?

I took an average model engineer and swung him by the feet on a rope suspended from the rafters, while he recited the following basic equation, until it sank in:

power = torque x angular velocity

and timed the oscillations to determine local gravity.

Andrew

[Martin WParticipant @martinw]

Andrew

I take it you swung said model engineer in a vacuum and from a frictionless pivot after having established the centre of mass .

Martin W

[Anonymous]

Posted by Bob Rodgerson on 29/12/2016 12:47:53:

I haven't used it yet but once I get Gearotic to work for me I will give it a try at making some bevel gears using very small cutters. Presumably that is what you intend to use it for.

Correct; I've used the 4th axis on the Tormach to make 6DP pinion bevel gears using a 4mm cutter. But for the traction engine governors I need some 18DP bevel gears. I can rough out with a 1.5mm cutter, but for the roots I need a 1mm cutter. At 5000rpm I estimate it will take over 17 hours to machine the gear. With a high speed spindle I ought to be able to substantially reduce that. Also, I hope that due to higher feedrates the cutter will be less susceptible to the inevitable small variations in feedrate.

In the past I have had a mixed experience with engraving on the Tormach. I came to the conclusion that I simply couldn't run the cutter fast enough to be reliable. I hope the new spindle will overcome this problem.

Andrew

[Bob RodgersonParticipant @bobrodgerson97362]

I have had success in the past with Gearotic but unfortunately since changing laptop I cannot get it to work properly. I have been in touch with Art Fennarty who is actually working on it to see if he can get me up and running.

I cut a large spur gear and a few sprockets using Gearotic and it took ages using a 2mm cutter and 5,ooo R.P.M. I haven't tried rotary engraving but using a Drag Engraver I have had great success. I have some helical bevels that I want to cut for an OHC engine I am rebuilding but until I get up and running with Gearotic again it will remain on the back burner.

At the moment I am using the CNC Mill to bore out a couple of cylinder bores in an alloy casting using a simple G-code that I did so that it cuts in and out of the hole using my Vertex Boring and Facing Head. Seems to be working well but the finish is a bit chattery.

[Anonymous]

Posted by Bob Rodgerson on 29/12/2016 17:06:51:

I have had success in the past with Gearotic but unfortunately since changing laptop I cannot get it to work properly. I have been in touch with Art Fennarty who is actually working on it to see if he can get me up and running.

I cut a large spur gear and a few sprockets using Gearotic and it took ages using a 2mm cutter and 5,ooo R.P.M. I haven't tried rotary engraving but using a Drag Engraver I have had great success. I have some helical bevels that I want to cut for an OHC engine I am rebuilding but until I get up and running with Gearotic again it will remain on the back burner.

Sadly I've never managed to get Gearotic working long enough to actually design a gear and generate code. On both the old and new computers it just seems to crash at some random point. Probably me; in the last company I worked at the IT guys used to hide when they saw me coming.

For the bevel gears made on the CNC mill I designed them from scratch in 3D CAD and then used my CAM program to generate the code. I used the 4th axis for the bevel gear pinion, but the larger bevel gears I mounted flat on the table and used a radial toolpath.

By helical bevels do you mean spiral? That would be an interesting project. I'm sure I could machine one if I could draw it. But drawing it is the problem! I guess one would have to create a loft from the outer tooth shape to the inner tooth shape along a spiral.

Andrew

[Bob RodgersonParticipant @bobrodgerson97362]

Hi Andrew,

I do indeed mean Spiral Bevels. Humber motorcycles used them in the drive from crankshaft to camshaft, 20 tooth driving a 21 tooth at one end and a 20 tooth driving a 41 tooth at the other (I think). I got three pairs of 20 and 21 tooth gears made many years ago and they cost about £450 for the three pairs which just seemed way over the top for me. However there was so much demand for them that the two spare sets were snapped up by people who were desperate to get their project bikes finished.

I new I shouldn't have sold them I have a couple of my own projects that need these gears.

Bob

Edited By Bob Rodgerson on 29/12/2016 17:54:15

[Les Jones 1Participant @lesjones1]

Hi Bob,
I think the 41 tooth should be a 42 tooth so the overall ratio is 2:1

Les.

[Tractor manParticipant @tractorman]

Today I built a stud wall over the roller shutter door of my garage based workshop and insulated it with 75mm celotex. Amazing the immediate impact on keeping the place warm. Made a personnel door in it to allow access and escape if needed. A couple of wipe boards and tool hooks and it looks like it grew there.

[Neil WyattModerator @neilwyatt]

Posted by John Haine on 29/12/2016 12:23:01:

I suppose if you are super critical you might want to allow for local variations in g, the acceleration due to gravity, but that might be getting silly

Oddly enough I'm well aware of that. I'm well ahead of you on the calculations, I've done all that and I did take local gravity into account.

Just as a matter of interest, how did you measure it?

There's a calculator on Wolfram Alpha

The main effect is latitude

Neil.

[Author]

Posts