Post Drill

[Boringgeoff]

Hi, I've just been given this post drill, rusted solid. I can't find any ID on it apart from 2189 cast onto the top of the advance wheel. As a guide to the size of this brute the hand wheel is 19IN diameter.
I've trawled through a few post drill threads here but can't find it, any ideas?
Cheers,
Geoff.

[macg]

Hi Geoff,

well this is one that I have not seen before,

I've looked through several catalogues and
yours looks to be a lower end model in that,
it only has the manual feed not automatic,
it is sparse in its design, very lean, all so
there is no mounting for the table shaft.


there were models with separate shaft mountings

it looks to be in good condition from your photos
is there any damage?

and is that (original) blue paint showing?
that might help with sorting the maker.

I wonder if it could be English??

it will be good for you to show it after
you finish cleaning it up.

Graham

[Boringgeoff]

Hi Graham,
We've been away for a week, I'm looking forward to having a look at it today. The blue hue is from the penetrant I've used to try and free it up. It's rusted solid but I did manage to get both wheels off before we left. Used the rattle gun got the nuts off, managed to wriggle the hand wheel off, the surface underneath wasn't too bad. Used a puller to lift the advance wheel which was quite rusted on.
This thread Cutting a coarse left hand thread. (https://metalworkforums.com/f65/t190169-cutting-coarse-left-hand-thread) on the Metalwork Forum describes how I made a conceptual replica of a fence post boring machine. The last couple of posts explain how wrong I got it and my intention to rebuild the machine as a replica of the original patent. To this end the reason I was given this post drill is to use the hand wheel from it on the replica. I may also need to use the drive shaft.
Having said that, I'm aiming to free the post drill up without damage as apart from the rust it looks in reasonable condition.
Edit: I'm hoping to have the replica finished in time for the Brookton Old Time Motor Show in March next year.
Cheers,
Geoff.

[Boringgeoff]

Took it out of the vise, upended it and quite surprised to find a square hole in the chuck rather than the expected round hole. The hole is tapered and pretty rusty and scaly, tried to fit a No1 Morse bit but only went in a short distance. The hole in the side of the chuck goes right through (2 holes really) has a thread 1/4" UNF or 6mm. Did Whitworth make a fine thread? The shaft for the hand wheel is exactly 15/16" which has me shying away from metric.
I found what looks like an L cast on the frame and Graham I must apologise, you're right there's definately a bluish bit of colour to it as can be seen in the 4th photo.
The ease with which the hand wheel came off makes me hopeful that the rest of it might come apart eventually.
Cheers,
Geoff.

[Chief Tiff]

What is generally referred to as “Whitworth” thread is BSW sometimes also referred to as BSC. The threadform has a 55 degree thread angle and rounded roots and crests. The fine pitch series is BSF and the last common Whitworth threadform is BSP used on pipe systems.

The American variant is Unified; UNC, UNF and NP. These run a 60 degree thread with truncated crests and flat roots.

Metric threadforms are similar to Unified with the 60 degree angles but obviously the pitches aren’t measured in threads per inch but a direct measurement in millimetres.

If one of the threaded fasteners happens to be 1/2” then the pitch would identify if it is Whit or Unified. 12TPI is Whit, 13TPI is Unified. Unfortunately all the other thread sizes in both systems have the same pitches.

The bolt heads may be used to identify Whit threads also; Unified bolt heads are always 1-1/2 times the thread size so a 1/4” bolt will always need a 3/8” spanner. Older Whit bolt heads are slightly larger than the equivalent Unified bolt hence why they had their own spanner sets; the spanner needed for a 1/4” Whit is closer to 15/32” across the flats and is actually marked 1/4” BS. Really old ones (pre 1930) were even stranger; BSF and BSC bolts had different sized heads for the same nominal bolt sizes and the spanners were marked with both sizes, eg the same spanner would fit both a 3/8” BSC and a 7/16” BSF bolt head.

Not confusing at all, is it?!

If you are able to confirm the place of manufacture that would identify the threadform used; US used Unified, UK & Aus used Whit and most of Europe used Metric.

[Vann]

Just to expand on this a little further...

...If one of the threaded fasteners happens to be 1/2” then the pitch would identify if it is Whit or Unified. 12TPI is Whit, 13TPI is Unified...Unfortunately that is only true of post-1950s when UNC was formalised (as far as I can tell). Before that Nth America used both 12tpi & 13tpi for 1/2" threads - and any post drill is likely to be pre-1950 (and probably pre-1910 :;).



...The bolt heads may be used to identify Whit threads also; Unified bolt heads are always 1-1/2 times the thread size so a 1/4” bolt will always need a 3/8” spanner. Older Whit bolt heads are slightly larger than the equivalent Unified bolt hence why they had their own spanner sets; the spanner needed for a 1/4” Whit is closer to 15/32” across the flats and is actually marked 1/4” BS. Really old ones (pre 1930) were even stranger; BSF and BSC bolts had different sized heads for the same nominal bolt sizes and the spanners were marked with both sizes, eg the same spanner would fit both a 3/8” BSC and a 7/16” BSF bolt head...Prior to WW2 BSF (British Standard Fine) and BSW (British Standard Whitworth) used different size heads, with the BSF sizes being one size smaller than the BSW head - e.g. a 7/16" BSW bolt would have the same size head as a 1/2" BSF bolt - and a 1/2" BSW bolt would have the same size head as a 9/16" BSF bolt, etc. Spanners from that period would be marked 1/2" BSF, 7/16" BSW (or more commonly 1/2" BS, 7/16" W).
And the size marked on the spanner has absolutely nothing to do with the size of the jaws :o:doh: - but instead, is the size of the thread of the bolt/nut.

During WW2, as an austerity measure, BSW heads were reduced to the same size as BSF heads, and stayed that way when the shooting was over - which certainly made a complex system a little simpler :roll:.

Here's a handy reference to thread sizes (and head sizes) http://www.oldengine.org/members/diesel/tables/mech1.htm

Cheers, Vann.

[Boringgeoff]

Thanks for that info CT and Vann. I checked the thread of the shaft holding the hand wheel, it's 3/4" 10tpi and the nut runs up a 3/4 UNC tap quite easily. As it would a Whit' tap too I imagine but unfortunately don't have one here.
From your info I can rule out US made and guess Aus' or UK? Add to this the lack of ID results here on an Aussie forum not Australian and because Vann hasn't told us what it is rule out NZ as well?
Cheers,
Geoff.

[Gaza58]

Took it out of the vise, upended it and quite surprised to find a square hole in the chuck rather than the expected round hole. The hole is tapered and pretty rusty and scaly, tried to fit a No1 Morse bit but only went in a short distance. The hole in the side of the chuck goes right through (2 holes really) has a thread 1/4" UNF or 6mm.
Cheers,
Geoff.
i would say the type of drill you are looking at for this is like the ones that just showed up on our local buy and sell.... bit of an ordinary image but you get the idea of what you are looking at...
462879
Gaza

[Boringgeoff]

Thanks Gaza, I should have said Morse square taper and in fact probably shouldn't even have said Morse. Just a square taper and could well be uniqe to the drill manufacturer.
Cheers,
Geoff.

[Gaza58]

I didn't even know these square tapers existed until I was researching Auger bits for my FW Reynolds mortiser.... There are so many different tapers/non-tapers used on various boring machines from the 19th Century... Everyone was inventing their own way to do the same thing. We are so lucky that things are somewhat standardized now Days.:)