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Member postings for Andy_G

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

Thread: PM Research#1 Cylinder Can it be saved ?
28/09/2021 17:50:10

Posted by Gary Bodnar on 26/09/2021 10:11:45:

…I mucked up my maths with the exhaust slot also, so for part of the depth the slot is a couple mm lone each direction.

Stupid day yesterday!

If it’s any consolation, the Blondihacks lady on youtube made the same mistake on her PM1, but didn’t mention it at the time. When attention was drawn to it in the video comments, she replied that it was “within specification’ !

(She also made a mistake with the height of the steam chest inlet and ended up catching the valve face with the tap when she tapped the hole.)

Thread: Turning (approximating) a Domed Surface
28/09/2021 08:53:30

Posted by Dr_GMJN on 27/09/2021 18:41:31:

Do you mean drive, say, a 0.8 radius tool to a series of locations, and blend the remaining peaks? I’d imagine I’d need dozens of positions to do that?

Or do you move the tool to subsequent locations by moving first in x, then in y to give steps, and blend the steps?

I stepped in Z by 0.2mm and turned to calculated X positions to generate the radiussed section at the right hand end of this part. Because my cross slide has a 1.25mm pitch, I converted my X coordinates to full turns & vernier readings to save mental arithmetic & inevitable mistakes during turning! You can see the crib sheet in the background.

Very little blending needed with a large radius tool.

I keep meaning to rig up a (manual) template follower, but haven’t got around to it yet.

Thread: Screw cutting
21/09/2021 09:08:14

Duplicate post!

Edited By Andy_G on 21/09/2021 09:08:55

21/09/2021 09:08:13

The least ambiguous description of setting the top slide that I’ve seen is at 5:06 in this video:


(Yes, the video is a bit wobbly, and he talks funny, but he explains things very well - the whole series is worth a watch.)

(Hopefully link works now)

Edited By Andy_G on 21/09/2021 09:19:15

Thread: Recommended Vice for Double Swivel Milling Slide
16/09/2021 09:05:14
Posted by William Harvey 1 on 15/09/2021 17:31:54

The Warco 9071 (60mm Jaws) and the larger 9360 (83mm Jaws) look ok, can I use the larger and the smaller one?

I think you only have 75mm cross slide travel on the WM180, so the 60mm wide vice is probably the most usable (bear in mind that some space is needed to be able to wind the cutter off the work, and it is occasionally desirable to be able to mill over the end of the vice).

I have a similar setup on a mini lathe with a 50mm wide vice and 70mm cross slide travel and occasionally wish for a narrower vice, but never a wider one (I’m sure I’ve seen a 38mm wide one that I was coveting, but can’t find it now.)


This is my setup - definitely get a vice that can be secured by through-holes (like the Warco 9552 or 9071).

Edited By Andy_G on 16/09/2021 09:07:16

Thread: Cylinder Head Combustion Chamber Template
14/09/2021 08:02:31

“If I make the template first, how on earth do I ensure the holes for the valves are correctly located?”

Can’t you poke a (suitably sized) pointed rod through the valve guides to mark the rear of the template when it is held in the correct position? (Then create holes at the marked positions).

Thread: Faulty Sieg C0 Lathe
23/08/2021 08:23:47

“the chuck does not revolve at a constant speed. It speeds up or slows down without any machining load being present.”

If the speed is constantly cycling or ‘hunting’ it could be caused by a badly adjusted controller board (there may be several preset potentiometers that could have been inadvertently disturbed.)

You may get lucky if you search for information using the code number on the particular board that you have.


(Edit to add: If the speed is varying randomly, it could be the speed control pot, especially if it shows signs of mechanical damage - they aren’t the best quality parts.)

Edited By Andy_G on 23/08/2021 08:29:21

Thread: Dipping a toe in TIG - what do I need (apart from skill)?
09/08/2021 18:30:47

A few videos, as promised.

The first is American, but bear with it - He summarises a lot of (IMHO) very sensible advice in one place. I forgot to mention filler metal above, but he also covers that well. His video on how to assemble a TIG torch is good, too.

The only thing I would add to the post above is to get a cheap 'peashooter' style flow meter so that you can check the gas flow at the torch, rather than trusting the regulator gauge.

Canadian, This Old Tony, sets up a valved torch from about 15 minutes into this:
If you do get into it, there's a lot of friendly and very helpful advice over on the MIG welding forum (I know a few regulars on here also post there).

Edited By Andy_G on 09/08/2021 18:34:31

09/08/2021 10:26:15
Posted by Robin Graham on 08/08/2021 23:57:59:
  1. What I know I don't know. This is a quite wide category. I had a look a Parweld TIG torches and they seem to be in the £150 ish range, but I don't understand the jargon - what are 'dual cable' torches for example? Do you get the gas line as well as the cable? If so, what fittings? Then there are much cheaper offerings elsewhere - but will the cables fit my Parweld (sort of bayonet cable plug) welder? Are these things standard size? I could go on about the (to me) mysteries of gas lenses, but I'll leave it here for the time being.


From somebody who was in the same situation at the end of last year (with a dedicated TIG set):

The socket on your machine is a 'Dinse' or 'Dinze' connector (35-50 if Google is to be believed). This is a very common size (the other common size is smaller) - it's easiest if your torch set comes with one already attached.

You will need a valved torch so that you can turn the gas on and off as (it appears that) the machine doesn't have a gas solenoid. It's easiest to buy a 'torch package' which comes with cable / hose / sheath and often a set of consumables.

The cable/hose needs to be one with a separate gas hose, (not a 'single hose' setup where the gas flows up the middle of the Dinse connector and the power lead is inside the gas hose, although adaptors are available). You will need a hose from your gas regulator with a suitable coupler for the gas connector on the torch cable/hose. Most gas fittings are 3/8 BSP Right handed, but some Chinese torch sets are metric - M10x1.0 seems common.

As above, get the biggest gas cylinder that you can. Note that different suppliers fill to different pressures - Hobbyweld, I think are 137 Bar which is quite low. To work out how much gas you're actually getting, multiply the cylinder capacity by the fill pressure.

Torches come in different size formats and water or air cooled - for simplicity / cost, stick to air cooled. Choices of air cooled torches are 9, 17 or 26 format (loosely based on CK model numbers). 9 is small, and neat, but limited to ~100A (or about 3mm mild steel, but will get very hot at this), 17 is a bit bigger, but still quite nice to use - limited to ~150A. 26 it more unwieldy, but can handle 200A+ (actual current ratings vary slightly by manufacturer, but are roughly of that order). Unless you have very specific requirements, I'd suggest looking at 17 size torches with a valve (usually designated something like 'WP17V' ) .

I have a Kennedy WP17 torch (from Zoro) which seems to be decent quality & fairly flexible - I'm sure they used to do a valved version, but it's not there now.

The torch may/may not come with a set of 'consumables' - back cap, collet, collet holder & ceramic cup. IME, these aren't particularly consumable (bar breakage). What comes with the torch should see you through your first few months of practice IMHO. If you don't get any with the torch, you will need to buy the correct set (which can be a bit bewildering). 17 and 26 sized torches share the same consumables; 9 series torches are smaller. Cup sizes are numbered by diameter: Get a 'middle of the road' cup - something like a 5, 6 or 7 to start with, but don't go overboard. There are cheap sets of consumables with a few different sizes on Amazon, etc. that appear to be perfectly adequate. You will come to find situations where a smaller (for tight fillet welds), larger or longer cup is needed, but they are cheap to buy when you know better what you need to suit the welding that you are doing. Larger cups need more gas; smaller ones are less forgiving. As long as you haven't gone to extremes, cup size is irrelevant when you're practicing.

Gas lenses need a different type of collet holder. The full sized ones are quite long, but the 'stubby' versions aren't much bigger than a standard ceramic cup. I would use them out of preference, especially if there's a requirement to have the tungsten sticking out further than usual. If your torch comes with standard consumables, I wouldn't bother changing them until you've had a bit of practice - Gas lenses can get contaminated by spatter when you do things like losing gas shielding because your torch position has drifted (or forgetting to turn the gas on!), so not ideal for your first steps. They won't make the difference between success and failure in learning, and there is an argument that you learn to be more consistent, more quickly, with a standard cup.

What are (very) consumable are the tungsten electrodes! Buy a pack! There is perpetual discussion of the "best" type of tungsten. Many of these differences are only relevant to AC - with inverter welders, I think the differences are subtle and linked to personal preference (there are umpteen videos comparing them on Youtube). It will not make the difference between success and failure when learning TIG. The advice I was given, and will pass on it to buy a pack of 2% lanthanated electrodes (pale blue colour code) in 2.4mm and stick with them. This has worked for me on mild steel & stainless (DC) and aluminium (AC). (You need to make sure you have a 2.4mm collet holder / collet in your torch.)

I have seen a couple of decent videos on setting up lift start TIG - I will add them if I can find them again.

Good luck  - I am by no means fully competent, but find it a very rewarding process. 


Thread: Running needle roller bearings
28/07/2021 14:02:09
Posted by steamdave on 27/07/2021 20:45:13:

Because the engine will be slow revving, developing little power (hot air engine) I will modify the design and use gunmetal bushings.

I think you will need to do everything you can to minimise friction, so plain bushes may not be the best idea. On the other hand. I very much doubt that the loads and speeds from a hot air engine would require hardened shafts if you wanted to stick to the original design.

Thread: Hit and miss engine
17/07/2021 19:47:35

If you come across a copy of "The shop wisdom of Philip Duclos" it has plans for the 'Odds and Ends' engine that Andrew Whale has just finished as well as several other hit and miss engines, and others besides.

Thread: Can auto darkening welding helmet capsule be restored.
17/07/2021 19:34:31
Posted by Windy on 16/07/2021 20:35:37:

If I can repair them easily would prefer to do that.

If they are the type with the small solar cells on the front, I believe they can sometimes be 'kick started' by leaving them in the sun for a few hours.

I have one of the cheap supermarket ones (Aldi, I think) with 2 arc sensors and while it is/was fine for stick welding, it wouldn't reliably stay dark with low-ish amp TIG. (A relatively inexpensive 'Tacklife' branded one with 4 arc sensors did work OK, however.)

Thread: Making an adjustable vice stop
16/06/2021 01:27:17

On your anodising - I use sodium bisulphate and it works well. There's definitely something wrong with your early attempts (maybe the readout on the PSU was wrong??) I spotted that you were using a steel screw - that's an absolute no-no. I work on 6A per sq ft which means I need ~23Volts at the end of the process (less early on) which is roughly what you were using on the second attempts and it takes ~2 hours to build up a reasonable thickness.(Some examples here: **LINK** 

IME, if the part will take dye after anodising, then the colour should hold after sealing. Your poor result at the end is probably due to a bad electrical connection somewhere - maybe where the hanger rests on the busbar (better to use clamp screws, rather than rely on gravity) or if you're re-using aluminium hangers - they need to be sanded or stripped in caustic between uses (titanium hangers don't.). Mark Preisling did a good video on this.

Thread: Etching Aluminium
15/06/2021 13:12:11

Thank you very much! (Well spotted! smiley )

Edited By Andy_G on 15/06/2021 13:12:28

13/06/2021 11:04:20

I know this is an old thread and Neil has probably sorted his etchings out years ago, but since it has come back to life, I can confirm that ferric chloride works well. My stuff has also been used to etch a small amount of copper which may/may not matter.


Edited By Andy_G on 13/06/2021 11:04:57

Thread: Steam Canoe Machinery
29/05/2021 08:55:05

Interesting project

From practical experience, I think that 2.6 HP would be way, more than required for a relatively slim hull:

A 2.2 HP petrol outboard would push our big, fat, inflatable dinghy with 3 people on board at more than walking pace on tick-over (this was an issue, as it didn't have a neutral!). At full throttle with one person on board, the thing could plane.

Rowing the same boat was a dismal experience - far less forward progress than a lesser effort in a wooden dinghy.

I think the ~0.5HP is much more likely. (Hull speed is ~5 kts, it becomes an exercise in rapidly diminishing returns if you are trying to exceed this.)

Thread: Distilled water for anodising
21/05/2021 08:56:29

I use the battery water from Halfords - it’s only a few £ for 5l.

There can be a lot of dirt in dehumidifier water, but it might still work OK.


Note that you don’t need to use sulphuric acid - sodiumbisulphate works just as well, is easier to get hold of and less dangerous to handle and have around.


(I’ve posted details on this forum previously, but they’re also here:

**LINK** )

Edited By Andy_G on 21/05/2021 09:00:02

Thread: Does anyone recognise this stuff [presumed Stainless Steel]
08/04/2021 20:11:23

That looks like a hot rolled mill finish -

I've got some stainless strip here that looks the same (one of the 400 grades, I think):

I suspect it's hot rolled & descaled, but don't know for sure. I've seen full (~2m x 1m) plates with the same finish.

There are several finish options - I would guess this is 1D or 1E

Thread: RH vs LH threads
29/03/2021 21:53:42
Posted by old mart on 29/03/2021 19:00:26:

I dont think anyone paid any attention to your answer, or understood its meaning.

It's still the right answer though.

Thread: Small Poppet Valves
26/03/2021 12:36:08

I turned some 3mm diameter x 20mm long stainless ones by turning the blank down in stages (roughly 1/3 of the length at a time) then taking a very light skim over the stem to blend the sections together, but 1.5mm probably won't stand for that.

Joe Pieczynski's approach may be of interest (one deep cut, right to finished diameter):

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