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Member postings for Dave S

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

Thread: Dressing / Truing a resin diamond wheel
29/06/2021 09:45:44

Morning all,

Im still building my tool grinder, but I have enough bits to do a few trial grinds to make sure that all the various angles and such work ok.

I have an alloy bodied resin diamond wheel that I am using - you can see it in this photo:

064e5434-7eec-48fc-9255-3c78dd8fd196.jpeg

I have had it for a while, and it’s been used on the previous iterations of this grinder.
As a result the face isn’t flat anymore.
What do I use to dress / make flat again?
I have single mounted diamond for my Surface Grinder, a number of scrap alox wheels, and a norbide dressing stick.

Dave

Thread: Re-making a centre hole in a small crackshaft
28/06/2021 12:16:44


Assuming a suitable sized lathe I would approach like this:

Given the bearing by the crank there is a reference surface there. Either remove the bearing, or use its outer race with some greedy soft jaws such as these:

182aa982-5e0e-4572-ae1c-6f90441f5114.jpeg


Bore in situ then you know that end is running true. Setup fixed steady on other true portion. If using outer race secure a drive to on of the jaws, and make sure the con rod isn’t flapping about.

Now if required can slap on some weld to build up if needed and then machine and remake centre.

Dave

Thread: 2D and 3D Cad Software Recommendations
22/06/2021 19:58:33

I tend to use LibreCAD for 2d for the laser cutter. Mostly like AutoCAD used to be and exports a DXF that the Laser understands - Fusion DXF is to new a version for the laser software.

Dave

Thread: So, you know about clocks!
22/06/2021 18:09:20

You could try Bernard Whitworth near Newark.
Afraid I can’t find his contact details, my google-fu seems weak today.

Dave

Thread: Locking Bearing preload nut
19/06/2021 22:15:24

Given the nut is pressing against a bearing that will spin freely it will have little tendency to unscrew.

As the bearings are "solid' the preload will not need to be continuously adjusted.

Simple solution, if it was me doing it, light or possibly medium threadlock.

Dave

Thread: Nickel Electroplating
18/06/2021 17:39:31

So if you stop at the right point you’ll end up with a nickel finish?

Might it depend on the voltage?

A different Dave

Thread: Securing workpiece for parting in lathe or 'left feed'
15/06/2021 21:42:39

I use centre support all the time on the CVA.

This is mystery steel, about 2" diameter:

e3yz0ccwuaawwuf.jpeg

Just remember to loosen it of as you get towards the actual cut off.

Dave

Thread: Can you recommend a UK supplier for good quality "mill board"?
15/06/2021 12:14:25

So there is an implicit symmetry in the stack up.
Fair enough.
can you get ~3mm board and mill the edge to the half thickness?

Thinking production you presumably will cut the parts from a larger sheet, so an additional op to thin the edges first saves a glue stack up op.

Dave

14/06/2021 21:25:52
Posted by John Smith 47 on 14/06/2021 14:33:48:
Posted by JasonB on 14/06/2021 13:25:55:

Can you make the core from one layer each of 1.0mm and 1.5mm which with the other items would give the total you desire.

Or if you want to make sure the structure is balanced then two of the 1.0mm with something 0.5mm in the middle of the sandwich.

Hmm... 1.0 +1.5mm isn't completely impossible, but it would mean fundamental changes to other parts of the design. Moreover if the product went into production the unwanted added complexity would add unwelcome cost.

So, yes, if all else fails... I'll guess I'll have to have another think about it but it would be must better to get two layers of mill board of the correct thickness!

J

Can you enlighten us about the fundamental changes that having an unbalanced 1+1.5 laminate would cause? In your stack up:

0.15 - Protective film (minimum)
0.05 - adhesive (guess)
1.50 - Gemimi Mill Board
0.05 - adhesive (guess)
1.50 - Gemimi Mill Board
0.05 - adhesive (guess)
0.15 - Protective film (minimum)

You make no mention of anything “in the middle”, and by your numbers it would add up to 2.9, just inside your sweet spot for thickness.

If you make it to production then presumably you’ll make an order for the right thickness of custom board, so no complexity there.

Dave

Thread: Strange mini "turret" lathe?
07/06/2021 22:01:44

That seems like a bargain.

Dave

31/05/2021 09:10:51
Posted by Michael Gilligan on 30/05/2021 22:38:49:

Drat and botheration crying 2

I was outbid

Did anyone here buy it ?

MichaelG.

Wasn't me, currently keeping free machine slot for a rose engine build...

Dave

Thread: Rotary Table Drawbar
30/05/2021 12:44:54

I sometimes stack my RT on a pair of 123 blocks - it only has 2 clamping points when in horizontal mode.

If I had to make that with a vertical only Index I think cuts A and B in the mill, then slot C with a hacksaw as a hand operation.


Dave

Edited By Dave S on 30/05/2021 12:46:28

Thread: How to adjust an EMCO Rotary Table
28/05/2021 17:06:37

It looks like the worm is on an eccentric?
If so it’s similar to my vertex rotary table.

I adjust for smooth travel with a little backlash and then only wind in one direction. That way the backlash doesn’t matter especially.

hth

Dave

Thread: Can one buy pliers with parallel jaws that lock like mol
28/05/2021 13:25:29

Posted by John Smith 47 on 28/05/2021 02:41:31:

> Why do you think the Mole grips will cope better than the Stanley 85-610.
I am saying that in the event that something important start to bend out of place, that the locking mechanism in the Stanley 85-610 looks like it doesn't has much adjustment as Mole grips.

Are you seriously questioning this?

It's just that it seems to me to be a self-evident truth, because ALL the opening and shutting in Mole grips comes from the position of one adjustable screw, whereas in the 85-610 the bulk of the adjustment come from the screw near the jaw, and there is no adjustment screw at the far end of it.

I think that your self evident truth is not (true that is).

On the mole grip the adjustment screw is not responsible for all the opening and shutting. The linkage is responsible for the bulk of the opening and shutting. The adjuster sets the end point for the linkage.

If you look closely, you will see that the screw adjust on the mole grips is where a fixed pivot is on the spanner, and the fixed jaw pivot on the mole grips is where the adjuster is on the spanner. The adjustment on the spanner is adequate for the maximum designed opening of the spanners jaws.

I don't know if you have ever taken an adjustable spanner to pieces, but the Jaw has a solid stop on the max opening, and the rack just drops off the end on the close side. This stops the moving jaw falling out when opened, and the massive fixed jaw stops it from falling out on the closed side. If you bend the linkage such that it wont close as far - presumably by being an unsympathetic ape - then the jaw will pass the worm further, until it hits the fixed side. I have mole grip which no longer fully shut - not because of bent linkages, but because the end of the screw has worn and it no longer presses the end point pivot far enough forwards to close the jaws fully. One day Ill fix them with a blob of weld, but the spanner does not suffer from that failure mode (as far as I can determine - i do not own one)

Remember also it is a spanner, not a clamp. Turns out that Makita also make one:model B-65470 Locking Adjustable Wrench.

Dave

Thread: How to mark out features which use the centre as a datum without a DRO?
28/05/2021 07:19:35

Or it could maybe be sleeved to reduce the size.
How did it end up over? Could be a useful learning opportunity there to avoid doing what ever it was in the future (such as the cylinder)

Dave

Thread: Gage block lapping?
27/05/2021 17:56:00

Evening all,

Im just having a tidy up and checking over my mics and gage blocks. So far the mic measures a selection of the gages correctly, so if they are wrong both of them have the same coincidental errors...

Anyway whilst cleaning and putting the blocks away I wondered how they manage to get such a perfect surface finish at such a (relatively) low cost?

Anyone got good links or info ?

Dave

Thread: Stupid moment
26/05/2021 18:16:14

So I was knocking out a little job for work - needed a HSS cutter thinned from 2.5 to 1.5 mm

No problem, plonk on surface grinder and make sparks.

All good, job done so clean down the chuck and wipe over.

Run knuckle against corner of wheel.
Now have big hole in knuckle. No more machining tonight

I should point out that the machine was off, and I’d raised the stationary wheel away from the chuck, both vertically and horizontally. But the corner of a 46 grit wheel is just like sandpaper...

As the late JS would say clumsy b@strd.

Dave

Thread: Strange mini "turret" lathe?
21/05/2021 22:17:55

Browsing through ebay, as you do on an evening I came across item 334008021715 - which looks like the offspring of a WW lathe and some sort of screw machine or turret lathe.

Can anyone shed more light on it?

It's clearly solidly built and certainly the tool you need to do whatever job it does.

I have no connection,and SWMBO is quite certain I don't need it...

Dave

Thread: Surface Grinder coolant aim?
13/05/2021 12:43:25

Thanks, I can see me remaking the coolant delivery pipe to be better placed.

I think I have a new set of videos to watch now.

Dave

12/05/2021 21:49:18

Evening all,

I have a 540 surface grinder, and to help keep the dust down, and give better finish I run a coolant hose on it. I guess it's a flood system, although I have to be careful not to open it fully as it pumps faster than the table drains.... Then it would be a proper flood.

Anyway I currently have the linelok aimed roughly at the grind zone from the back of the wheel - so the coolant is flowing in the same direction as the wheel is running.

This seems to work ok,but i wondered tonight as i was grinding an old crankshaft of i should really aim the coolant against the rotation?

Any comments?

Dave

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