Hole layout 101

[jack620]

Looking for suppliers who will ship spotting drils to Singapore.

Gus,
Chan Man Lee in Rowell Rd sells them. I bought an Australian made P&N 90 degree 6mm spotting drill for Sing$9.00 last week.

 

[Tin Falcon]

Keep in mind there are various layout methods and tools.

There is semi precision layout that typically give a result of +- 1/64 of an inch or 0.015inches. On a drawing set specified in fractional inches +- 1/64 is the normal tolerance. that is where you use the 6" rule and calipers to scribe lines. But this may not really be good enough.The methods I described should give a +- 0.002 result.

About 12 years ago I started working in a professional model shop. I was given a simple part to make the print was in fractional inches so that told me the tolerance was +- 1/64 I made the parts and was told they were not good enough. the foreman remade them . later I had to do a bolt circle I calculated the coordinate to use the dro the foreman was surprised because the guys had always layed out the holes with dividers. He was happy that I was using a more accurate method.

I am a machinist not a mind reader. The good thing is in the home shop you decide what is good enough. You can decide what methods to use and what results you need.
Tin

 

[old-and-broken]

www.books.google.com/books?id=oV4PAQAAIAAJ&pg=1

 

[Tin Falcon]

Nice one.
Tin

 

[jack620]

How do I download the book? There's no Download link.

 

[Tin Falcon]

click on the link you will see a little gear icon on the right upper part of the screen click on the down arrow next to it. then click on download pdf it will take you to another screen type in the squiggly letters in the block and click on the submit button.
Tin

 

[gus]

Gus,
Chan Man Lee in Rowell Rd sells them. I bought an Australian made P&N 90 degree 6mm spotting drill for Sing$9.00 last week.

Thanks Jack,

Will drop by Rowell Rd to look see. The trouble with local tooling suppliers,we seem to have specialists---pressure/temperature gages only, bearings and oil seals only,power tools only,bolts and nuts only. Tooling shops in China have a very wide range of tools. Will call a CNC Machineshop mate for leads to some supermarket type.Keep you informed.



Bought one 3/16 from Ebay which cost me US$7.22 w/o DHL added on.

 

[goldstar31]

Gus,

What you really want is something called a 'Spear point drill' as old as Archimedes or older.

One simply knocks them up from scratch. If you eyesight holds up- make them from darning or even sewing needles

Cheers

N

 

[gus]

Hi Norman,
Seen this as a carpenter's bow driven drill. Please advise source of drawings or sketches.

Or will a very sharp pointed spade drill do the job?

Come 7th Feb 2013 ,Gus will take his better half 68 young lady to Osaka. Both will be at TokyuHands window shopping. Will need a tight hold on Credit Car.Too many goodies to look at and too tempting.

 

[goldstar31]

Hi Gus
these tiny little drills are tiny little copies of the old carpenters much bigger ones.
You can only get one cutting edge on each side because they are too small. Probably the best source is reading old books on clock and watchmaking.

Incidentally, Kung Hay Fat Choy in the Year of the Snake.

Enjoy your holidays. I'm starting mine at the weekend

Norman

 

[gus]

Hi Gus
these tiny little drills are tiny little copies of the old carpenters much bigger ones.
You can only get one cutting edge on each side because they are too small. Probably the best source is reading old books on clock and watchmaking.

Incidentally, Kung Hay Fat Choy in the Year of the Snake.

Enjoy your holidays. I'm starting mine at the weekend

Norman

Hi Norman,
To make it authentic,Gus will use Chinese Text for the CNYear Greeeting.
恭喜发财！！！！ KungHayFattChoy。

Will go into clock making webs to look for spear drill. Seen my uncles next door using it. These old carpenters just won't touch a power drill but their skill is first class. All dead by now.Did picked up some skills from them.Nobody will pay too much for a handcrafted Camphor Wood Chest and Cabinet.:wall::wall:
Gus is not a great carpenter.You cannot be when you buy "cut to size" plywood and knocked together with power drill,power screw driver and square and cover up the flaws with Formica. Ikea ckd furniture is too expensive & flimsy. Build two three drawer locker for a song.:
Will be window shopping a TokyuHands,Osaka,Japan.A handyman's paradise.
No worry .Gus will not overspend.

Getting very hot and humid now.:fan::fan::fan:

 

[goldstar31]

Hi Gus,
drop me a note of your proper e-mail address and I will copy the bit from Ian Bradley's The Drilling Machine.

Meantime- I'm off to feed the Dragon.

Cheers

Norman

 

[gus]

http://www.gadgetbuilder.com/OpticalPunch.html

http://qrp.webhop.net/Metal_Bashing/Optical_Center_Punch/Optical_Center_Punch_Tool.html

Hi Alchymist,

Plan to make one to pop crtical centers. The normal centres will stay by eyeball. Thanks for the link.

Gus Teng,Just got back from freezing cold :wall::wall:9---2 C Osaka,Japan back to nice & warm 26 C Singapore.