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New from Old / Re: The Sequel - Oh Blimey I bought a CNC Lathe (Beaver TC 20)
« Last post by Muzzerboy on November 11, 2026, 07:06:17 AM »
I think I'd have reached for the TIG myself if that had been mine. Between the added leverage of a large bolt welded to the head plus the effect of heat, I'd be surprised if it didn't budge. But there's no right or wrong method.

Csk machine screws with hex sockets are one of the least effective and most troublesome fasteners - hard to tighten adequately without damaging the head and a sod to remove when they get clagged up after the passage of time and corrosion.
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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 11, 2026, 06:19:19 AM »
Another TWIT moment of course - the bolt shank is 12mm - assuming that the 9.5 mm hole is approximately concentric (it isn't quite) then there will be (12-9.5) / 2 wall thickness left or 1.25 mm which will have very considerably weakened it but it's very  tough steel. I'll have a go with a punch and see if it'll shear off.Very well supported of course as it's snugly sitting in the female countersink.

(a 12 mm Cintride bit is north of 50 UK pounds)
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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 11, 2026, 05:52:52 AM »
In a dark corner of my brain I had a vague recollection of having a few 'Cintride' brand solid carbide drills - just maybe they might work. Intended for slow speed drilling of hard steels in a machine tool able to exert significant pressure while rotating. Well I'm forced to use a hand drill so the 'significant pressure' is limited to what I can apply with my tummy  :lol:

OK I found the box, mainly empty cardboard boxes but I did have one 9.5 mm solid carbide genuine Cintride so lets see what happens:

I've managed to sink the hole now to 13 mm deep - there can't be much material left of the countersink - I'll have to do some maths -

  [ You are not allowed to view this attachment ]  

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- go do the Maths Andrew !
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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 10, 2026, 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 November 10, 2026, 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 November 10, 2026, 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 November 10, 2026, 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 November 10, 2026, 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 November 10, 2026, 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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