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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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Thread Tools |
23rd Jan 2021, 7:44 pm | #41 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Centre drills vs Spot drills.
Here's a few holes cut with a hole saw (Bosch) it was to see how many the drill would do continuously on one fully charged battery....almost 6 holes, the timber is tough stuff (Spruce) I have a full set of Bosch ones and a special for doing 110mm for the large waste pipes, I mainly used that one with a mains powered drill that I could extend the side handle on.....
Lawrence. |
23rd Jan 2021, 8:03 pm | #42 | |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Centre drills vs Spot drills.
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If the proper drill bit is used it shouldn't drift because of the type of flute, it ensures a tight hole, it's that tightness that is used to eject the plug, at least it is with the Bosch system. Lawrence. |
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24th Jan 2021, 8:06 pm | #43 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,106
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Re: Centre drills vs Spot drills.
Thanks David for the information in Post No.32. (link to Marius on YT very useful)
I so rarely have to use a holesaw ('tank cutter') bit that i never learnt how to do it properly. Following the advice i completed three 2" holes in thin ply without the heat build-up, jamming and clogging. Obvious when you think about it- if you don't get rid of the sawdust you may as well be a boy scout starting a fire with friction. A couple of things to add- look out for off centre cheap arbors and cheap slightly oval holesaws....and attack the wood from the reverse side to finish the hole if possible. Dave |
25th Jan 2021, 12:38 pm | #44 | |
Nonode
Join Date: Jan 2016
Location: Stafford, Staffs. UK.
Posts: 2,532
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Re: Centre drills vs Spot drills.
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25th Jan 2021, 10:01 pm | #45 |
Hexode
Join Date: Aug 2014
Location: Featherstone, West Yorkshire, UK.
Posts: 386
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Re: Centre drills vs Spot drills.
Going back to my engineering apprentice days, We were shown how to apply a blob of plasticine onto the end of the closed drill chuck, push a needle into it and then centre the needle by touching the needle as it rotated. Once centred, the pin was lowered toward the centre punch of the hole and carefully lined up, looking the front and the side. Once lined up, the hole could be drilled (small pilot to start it), followed by the correct size.
We never had any holes out of alignment. |
26th Jan 2021, 12:04 am | #46 | |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,844
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Re: Centre drills vs Spot drills.
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26th Jan 2021, 4:35 pm | #47 | |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: centre drills vs spot drills
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Thin metal needs a support or the metal can bend. For larger holes I'd recommend something like a Qmax hole punch. |
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28th Jan 2021, 8:20 pm | #48 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,761
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Re: Centre drills vs Spot drills.
In Lidl this morning, which is the day they display their latest 'Lidl in the Middle' 'when it's gone it's gone' offerings. Coincidentally, they had a set of six bimetallic hole-saws - 22mm, 25mm, 35mm, 44mm, 68mm and 73mm diameter. (Tested and certified in Germany). Couldn't resist them at £9.99.
Lots of other electrical and hand tools including a rotary 'Dremel' style tool, variable speed from 10,000 to 40,000 RPM, flexible shaft, keyless chuck, routing base, stand, 42 attachments, and an LED (battery powered) light attachment. (£19.99).
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David. BVWS Member. G-QRP Club member 1339. |
29th Jan 2021, 12:26 am | #49 | |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,934
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Re: Centre drills vs Spot drills.
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