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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by awemawson on Today at 11:57:52 AM »
It did occur to me that it possibly could be a left hand thread, but there is no valid reason why it should be as the tool disk is rotated in both directions by the servo with the logic working out which way is quicker from 'current tool' to 'desired tool'

I did however try left handed vigorously with the big ugga-dugga !
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by smiffy on Today at 11:51:51 AM »
Is it possible they are left handed threads ? or some times tightening a bolt can loosen one that refuses to come undone when turned in the correct direction  Mike
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by awemawson on Today at 09:17:40 AM »
Well another try:

I've managed to drill a 6mm  hole 20 mm deep into the back of the hex driving recess using an HSS carbide drill. Went in remarkably easily. Next size up that I have in HSS Carbide is 8mm - total rejection, just polishing the edge of the hole. Tried another brand new HSS carbide in 8 mm with the same result.

I can only assume that the core of the screw has been left relatively soft with the rest at 12.9 hardness.

It seems that 12.9 steel needs to be brought up to 400 Deg C to soften and I'm getting no ware near that with my propane torch. I do have a Mapp gas cylinder but that only burn a few degrees hotter so probably not the solution.

I've a pair of big old Oxy-Acetylene cylinders out side in the safety cage but I dread to think what the state of their hoses is - not been used in a few years. The logistics of getting them near the bench will be challenging.

. . . more cogitation  :scratch: :scratch:
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by John Rudd on Today at 07:21:40 AM »
Quote from: AdeV on November 09, 2026, 06:01:44 AM
Quote from: awemawson on November 07, 2026, 07:27:12 AM
...I have to go to Heathfield and buy some sheep wormer !

Can't you just put sugar in your coffee like the rest of us?  :lol:

Seriously though - excellent progress! And I see you've just posted, so now there's another episode to read  :thumbup:

Strangely enough, I find all this very entertaining to the point of its stopping my own work progress... :clap: :clap:
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by awemawson on Today at 06:37:14 AM »
Still no joy. took it to just under 300 degrees C and held it there until my finger holding the torch trigger went numb!

Got the hex bit stuck in the hole, eventually freed clamping a Mole Wrench on it and using levers - this is getting silly. I dug out an extended length decent quality Allen Key and whacked it with a big hammer trying to shock it free whilst still pretty hot - no joy.

If I have too drill the head off the bolt it's not the end of the world as after all all I'm trying to do is see how this beast is held together before attacking the 'real' one, and don't intend to use this shaft, but a shame to ruin it.

CHATGPT tells me a counter sink headed bolt with a 25 mm diameter head and an 8 mm drive socket is probably an M12 thread so when it's all cooled down I'll see if it succumbs to drilling.
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by awemawson on Today at 05:29:13 AM »
Disappointingly another fail this morning. I've taken the counter sunk head of that axial retaining bolt up to 150 deg C and still it won't let go using my biggest battery powered impact wrench set to maximum Ugga-Dugga's .
I am concerned that even if I manage to rig a massive torque amplifier to a conventional Allen hex key it's just going to twist off. The socket is only 8mm hex and as it's going at the moment the 8mm driver gets distorted enough to make withdrawal an issue.

May be even more heat?  After all the shank of the bolt won't be anything like 150 C as the shaft acts as a big heatsink. Maybe the same heat for longer?

NB this Impact Wrench successfully take wheel nuts off my JCB and various tractors so it's no weakling

Or maybe a different hobby !

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Member Videos / Re: All Metal 5 Cylinder Radial Aeroplane Engine Demonstration Model Build
« Last post by John Rudd on November 09, 2026, 02:29:17 PM »
If it were me, I?d confirm the firing order?if they?re sequential then it?s a matter of lighting the leds to follow the sequence?using the triggering mechanism used for generating the spark for each?.

If this isn?t the case, then I?d need to know how the spark is triggered for each cylinder, using the trigger, this could be used to ?enable ? a transistor to drive? each led?

A bit more info please?.


Typing gremlins have crept in?
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Member Videos / Re: All Metal 5 Cylinder Radial Aeroplane Engine Demonstration Model Build
« Last post by AdeV on November 09, 2026, 06:09:22 AM »
Quote from: Jim Dobson on November 07, 2026, 10:01:31 PM
Has anyone got any ideas how I could mod this so that a small red LED could 'fire' when the piston is at the top stroke and in the order that a radial engine fires?

MikeC would probably be the best guy to confirm this - but from my limited understanding (if I was listening properly at MMEX earlier this year), all radials fire when the cylinder is at the top of the circle (I guess that would be the bottom if the aeroplane is inverted!). I haven't watched your video yet, so I don't know if you've built the ignition setup - if not, you'd ideally need to do that, then you can simply run 2.5v up to the "spark plug" using the spark wire(s) themselves.
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by AdeV on November 09, 2026, 06:01:44 AM »
Quote from: awemawson on November 07, 2026, 07:27:12 AM
...I have to go to Heathfield and buy some sheep wormer !

Can't you just put sugar in your coffee like the rest of us?  :lol:

Seriously though - excellent progress! And I see you've just posted, so now there's another episode to read  :thumbup:
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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by awemawson on November 09, 2026, 05:58:40 AM »
Today's objective - dismantle and remove shaft.

The first obvious thing to do is unscrew the axial countersink bolt from the end of the shaft which should allow the 'hedgehog' position sensor drum and curvic coupling to slide off. They are presumably keyed to the shaft.

  [ You are not allowed to view this attachment ]  

Well no - that wasn't playing ball  :bang: So I decided to remove the rear part of the casting which is aluminium and bolted by a ring of M6 cap screws to the front steel casting. The idea being to get better access. Someone has obviously been in here before as half the M6 bolts were missing.

  [ You are not allowed to view this attachment ]  

Although access IS now far better still no progress with that counter sink screw with it's M8 socket.
I will play a hot torch on the assembly later and see if it loosens up. May well be loctited, or just loosen with expansion but I'm now called away to other duties.

Disappointing but that's how it goes sometimes.

Remember this is just practice - this tool post won't be used - you an see the crack in the picture above.
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