Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: Jim on May 08, 2019, 10:21:37 pm

Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Jim on May 16, 2019, 08:50:09 pm
A razor blade is a good idea Bruce.
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: St Paul Steam on May 16, 2019, 06:52:56 am
good helpful hint Jim, I have used this technique since I learned it from your thread on the Mamod forum, although I use a flat (no binding) razor blade.
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Stoker on May 11, 2019, 10:23:49 am
But we don't have squirrels.....I have a thing for squirrels that are so cute!

Well in reality, squirrels are just a different form of rat with a prettier tail, but I too like squirrels, unless they are stealing my Gorp, but then again, I also like rats and mice, unless they are causing me some form of problem, which is often the case around here.
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Jim on May 11, 2019, 01:20:32 am
But we don't have squirrels.....I have a thing for squirrels that are so cute!
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Stoker on May 11, 2019, 12:49:52 am
You folks Down Under have the coolest critters!

And some of the most uncool too as I understand it !!!
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Jim on May 10, 2019, 09:19:23 pm
Our 1c pieces that went the same year as the 2c.

The Queen and on the back a feather tailed glider possum

[attachimg=1]
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Stoker on May 10, 2019, 09:03:25 pm
Nah Jim .... that's your guys two cents worth.

Here's ours:

[attachimg=1]

I must say that bust of the young Elizabeth looks to be more than a match for that cool lookin' lizard.

Our two cent piece has been out of circulation a lot longer than that, but our one cent "penny" continues on.
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Jim on May 10, 2019, 08:47:39 pm
Daniel, I welcome your 2c any time mate :)

Though you might have to up it to 5c now as Australia took 1c and 2c pieces out of circulation in the late 1990's

Here's our old 2c and we had the Queen of course on the front and a frilled neck lizard on the back.

[attachimg=1]
Title: Re: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Stoker on May 10, 2019, 08:08:07 pm
Just a couple of "off the cuff" comments on this technique Jim.

First off, I'll say simple is best whenever you can manage it, and I think this technique truly qualifies in that category!

While the mechanical capture between the point of the center drill and the "peak" of the cylinder is key, gravity can still have some effect on the results obtained, so I'd suggest always trying to use the rule as close to its true center as possible, and perhaps best not to use one that has a hole and a different profile on one end, such that the balance point is not true center.

Another point to consider is to make sure that the place to be drilled has no dings, dents or other deformities within the bearing area of the rule you are using, as that would cause an aberrant deflection, different from a true tangent at the "peak" of the cylinder.

Just my 0.02 cents worth.
Title: Shed Talk - Easy way of finding centre to drill a hole in round stock
Post by: Jim on May 08, 2019, 10:21:37 pm
Shed Talk - Easy way of finding centre to drill a hole in round stock

Easy way of finding centre to drill a hole in round stock. I know that a lot of blokes (and gals) know this trick, but I'm sure that there's a lot that don't and it's always good to refresh an idea now and again. I know that true machinists have better and more accurate ways to find centre, but for your average backyard metal basher this is a quick and easy method.


https://youtu.be/d9i3MEuhgmI