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Member postings for JasonB

Here is a list of all the postings JasonB has made in our forums. Click on a thread name to jump to the thread.

Thread: water supply
16/06/2019 07:31:59

So you would be happy if the authorities invest some of their money to compulsory purchase your house and flood your village to make another reservoir devil At least it would stop them errecting a wind turbine at the end of your garden!

Edited By JasonB on 16/06/2019 07:33:08

Thread: Carbide inserts tool holders.
16/06/2019 07:04:48

As Jimmy says you may be able to machine the cheaper ones but a named brand may be harder, I've taken the corners off a set of face mill inserts trying to tale a good US brand holder down in thickness.

Thread: Hardening a form tool made from Gauge Plate
16/06/2019 06:58:08

Strange that the M-machine link says that bright rid is colder than cherry red, I would have said 500degC was cherry red and 8-900degC bright red.

Thread: Metric threading on Imp Lathe
15/06/2019 19:11:26

That's it. just not sure if you will get the smaller gears to mesh without leaving a gap.

15/06/2019 18:29:57

Problem is all the old change gears knoocking about are going to be imperial you need a metriv MOD gear. Not too expensive to buy a stock gear from someone like Beltingonline and modify it to fit.

Neils you are right it's a lot closer I hit 3.125mm for the leadscrew pitch not 3.175blush should come out at 1.50019

Not sure if it will fit on the banjo but you could try 40T spindle driving 80T, 63T driving 40T, 60T driving 50T on leadscrew and put the lever in C. Which basically doubles the drivetrain pitch but by changing the lever you run at half that.

15/06/2019 16:08:56

I actually have a 280 but there are quite a few 250 owners here who will hopefully chip in later.

The feeds are really nothing more than very fine threads so you set them up in the same way, having said that in the 10 years that I have had my 280 I just use the finest setup and use the lever to get 3 feed rates which seems to work OK for me, you do still get a very fine facing cut with the lever in the "C" position even though it is shown blank

Thread: traction engine pump
15/06/2019 15:10:42

If this is on your D&NY then you won't need much suction to lift the water into the pump as it sits below the tender floor level and should almost be self feeding. it only needs to push the water upto the clack or back to a separate bypass valve.

Are you testing it with a clack in place or just trying to pump from the tender to the pump outlet?

 

Water from tender enters bottom of pump, outlet goes to a tee and either to the boiler or to tender via bypass valve

 

Edited By JasonB on 15/06/2019 15:15:19

Thread: Minnie 1"
15/06/2019 14:50:22

You want the hole deep as it is the plates you are setting together, you are not expanding the rivit.

All sounds OK

get the practice in now where it does not really show

Thread: Hardening a form tool made from Gauge Plate
15/06/2019 13:32:59

Not sure about tha, this one for expmple held up OK for making these brass fittings

And with a bit of regrinding (not to the cutting edge)went on to cut a batch of steel decorative nuts, still has a sharp edge

If it were not hard I would have expected the steel hex to blunt it. I know the likes of Ramon seldom tempers his homemade cutters and he used to do a lot of hardening for a living though he does have a tub of whale oil to hand.

 

I do feel that the section of the part being hardened can have an effect, if you have machined the cutting edges then they will be thinner and pointed and will quench faster than the bulk of the part so you can get a harder edge with a less brittle body so the tool may not shatter but the edge could chip.

Edited By JasonB on 15/06/2019 13:37:38

Thread: Metric threading on Imp Lathe
15/06/2019 13:19:02

Nicky your image has not come out but I assume you have similar to this though there are a few WM250 variants.

The top chart is the fine feed chart with cuts along teh lathe shown first followed by finer cuts, below that are the metric pitches and then the imperial ones.

The group of circles is basically what you would see if you take the end cover off the lathe and look at it from the end. The top left circle is the fixed 40tooth gear on the spindle, then you have two pairs of gears Z1-4 on studs which can slide along the banjo and finaly gear L on the end of the lead screw.

You can now look down at the table and it shows what gears need to go in the Z1-4 positions as well as L to get the gear you need. AB&C are the position of the front lever eg one gear train will give 3 pitches. H on the chart means a spacer.

So for 1.5mm itch you need 63T and 80T on tehtop stud with teh 80T nearest the headstock, then 80T and 60T on the next stud with 60T nearest the headstock and finally a spacer and the 50T gear on the lead screw with 50T nearest the headstock and select lever position A. The studs can slide on teh banjo to mesh the gears correctly and the banjo also pivots around the leadscrew to adjust mesh with the fixed 40T spindle gear. You should have two 80T gears.

You won't get an exact 1.5mm pitch using a 63T in the train but the resulting 1.477mm should do for most things.

 

Edited By JasonB on 15/06/2019 13:24:53

Thread: Supply of machines
15/06/2019 10:44:41

Boxford VM30 has feed by raising the table so as good and any Bridgeports fine feed. What it does not have is a quill feed so a bit of a pain in the arm if you want to use it for drilling. Also variable speed via the cone pullys so you get the best of both systems

Thread: I F Allman in 1/3rd Scale.
15/06/2019 10:41:11

Ron the choice for me is usually dictated by whet was on the original and as most of what I make are older engines then plain bearings are the usual option. I did use ballraces on my flame licker for reduced friction and the Forest also used them as it was destined to work that way too, had I planned an air/steam one from the start then plain bearings would have been used. Also a couple of the model aero engines have ballraces though not all with some again having plain.

having said that these couple of videos will show that plain bearings don't drag that much, first is plain, second ball races.

As for paint although I have a good collection of airbrushes and small spray guns 9 times out of 10 I will just use spray cans. On this one some of the rougher castings had U-Pol "High 5" which is a high build filler primer, the non ferrous had U=pol's "Acid 8" etch primer then all had a coat of Halfords grey primer followed by their Satin Black and finally a clear coat in this case a fuel proof satin.
Thread: Learning CAD with Alibre Atom3D
15/06/2019 10:25:49

Similar to David's suggestion of a chamfer is to sketch a random shape with one side at 90 degrees to the angle of your hole, the long edge in this case

port1.jpg

Then extrude that to any length I went with 1"

port2.jpg

You then just select that surface to sketch on

port3.jpg

Then once again cut to geometry

port4.jpg

You can go back to alter the angle of your first line or move the circles if need be. Then just select the cut extrusion on the left hand list by right clicking and select "suppress" so it does not show on the model. Final thing on a cylinder like this is to mirror the cut extrude of the drillings about the central plane.

port5.jpg

 

Edited By JasonB on 15/06/2019 10:29:52

15/06/2019 07:53:55

Well it came out a bit fuzzy but should give you an idea of how to first set a plane at the desired angle and then I added an offset plane to that before sketching on the offset plane. Also a bit of editing as the holes were cutting into the cylinder sides. I think Atom has the same plane options if not post a screen shot of what options come up when you click the "insert ref plane" tab.

Thread: Supply of machines
15/06/2019 07:06:54

Mike you are correct, a lot of the smaller "back alley" outfits are being forced to close as they can't afford to clean up their acts and this puts more load on the better makers who are doing what the governments require.

I know from talking with our suppliers that the companies that they buy from now have a 12month or more lead in and at least one has stopped taking orders for the moment (actually that is an indian one)

This is also going to mean increasing costs being passed on as the makers have to cover the costs of updating their set up.

Maybe Ketan will chip in as he has first hand knowledge.

Edited By JasonB on 15/06/2019 07:09:58

Thread: Learning CAD with Alibre Atom3D
15/06/2019 07:00:19

You need to create a plane that is at 90degreed to the hole you want to draw, then it is just a case of sketching a circle on that plane and cut extruding it. An alternative is to add an axis then draw a half section of teh hole and cut rotate about the axis.

Give me a while as I think Atom is slightly different for adding planes than my Pro version and I'll see what can do.

Thread: I F Allman in 1/3rd Scale.
14/06/2019 20:27:54

You have seen odd bit sof this engine in teh workshop progress thread over time and with teh Forest engine running well I thought I may be on a bit of a run. So armed with a new cylinder of propane thought I would give this one a go to see if it had gone back together OK after painting.

It took a while to find the sweet spot. First of all it had a tendency to fire too soon which I put down to too high compression. Now I may only have a green dragon machine that some say won't turn concentrically and only have a cheap brake cylinder hone not a smelly proper Sunnen machine yet with just one vitron ring fitted I was getting very good compression infact almost too much which resulted on it firing every 3 or 4 cycles and petering out usually ending in a backfire that sent it violently into reverse before stopping.

Then I had a enlightened moment and remembered that when building the engine I had found that there was less compression when the primary exhaust was open as the piston does not cover it until part way towards the head so took out the plug and gave it a try. Certainly ran with a loud pop and threw out a few large flames at crotch height surprise. However it still did not fire on every stroke and seemed weak and would again slowly die but at least there was no backfire.

Finally found the sweet spot with the primary exhaust plug left slightly loose which acted a bit like a decompression valve and away it went. It's always nice when you can choose when to stop an engine rather than snip the video short just before it comes to a halt by itself and just show that its not what you have in the workshop that matters but what you do with it and subsequently comes out the door devil

Another big thank you to Graham Corry for making the patterns available again and for the help and encouragement along the way.

Thread: Cast iron dust , is it really that bad for lathe beds.
14/06/2019 20:19:52

Hope you made the rings before you cleaned up.

Cylinders look very good.

Thread: Hardening a form tool made from Gauge Plate
14/06/2019 18:20:27

I would not bother to temper, just use it hard.

Thread: traction engine pump
14/06/2019 18:17:56

Have you got the bypass open?

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