Thread: Boynton & Plummer Post Drill

Vann, you have certainly got your work ahead of you !
Just out of curiosity what colour will you paint it and do you have access to a sandblaster ?

Melbourne Matty.

Originally Posted by L.S.Barker1970

Vann, you have certainly got your work ahead of you !

Hi Matty. I bought it out of curiosity - to see how this manfacturer did things, compared with others. There seem to be a number of unique features (whereas Canadian Blower & Forge and Dawn do almost everything the same as each other). The idea is to de-rust and repaint it - then slowly work on options for the missing parts over a number of years. It doesn't matter if I never complete it - 'though it would be good to.

Originally Posted by L.S.Barker1970

Just out of curiosity what colour will you paint it and do you have access to a sandblaster ?

I don't have a sandblaster (nor access to one - short of using a professional company). I stripped it using paint stripper, then a cup wire brush in an angle-grinder. Finally a dremel for the corners the brush missed.

The post drill is going to be mounted on a wall between a black Silver and a black Green River, and I wanted to get away from black for this one. I repainted the pillar foot and table fork in grey (left over from my Canadian Blower & Forge No.61), but wasn't sure if I should continue with that colour. The only photo I have seen of another No.1½ is painted black. However I've seen two of their No.2 in red livery, and looking at other photos of rusty No.2 models, there could be traces of red there too.

Undecided, I had a discussion with DSEL off forum, regarding a linseed oil finish he's trialling. But while mucking around with the dremel this morning I ground off some casting defects - then decided the bright spots would most likely detract from the see-thru linseed oil finish - and now I've primed half the main casting in grey primer. Unless someone talks me out of it in the next day or two, it'll be Canadian Blower & Forge grey.

Cheers, Vann.

Since my last posting I've mounted a macrocarpa post to the wall - with mounted bolts pre-fitted from the back, and period square nuts sourced (from Australia ). The main frame casting has been painted, and the casting bolted and screwed to the post. The feed wheel and spindle cog have also been de-gunked, de-rusted, and painted, and the feed-nut and screw have been derusted and lubricated. Reassembly has started.



Also progessing is the crank assembly. Unlike any other post drills I'm familiar with, Boynton & Plummer used a separate cast bracket to mount the flywheel shaft with it's cog. The same casting also holds the crank shaft with it's main crank cog...



This has been disassembled, de-gunked, derusted, and yesterday the two cogs and the bracket received a coat of metal primer.



I've stoned off a few burrs from the two shafts, but they might need a little more work yet.

Cheers, Vann.

Originally Posted by Vann

with mounted bolts pre-fitted from the back, and period square nuts sourced (from Australia ).

Cheers, Vann.

Looking the Part Vann, I'm liking the colour and the stand out lettering !
Finding square nuts over here is no easy task, love to know your source ?

Melbourne Matty.

Originally Posted by L.S.Barker1970

Looking the Part Vann, I'm liking the colour and the stand out lettering !
Finding square nuts over here is no easy task, love to know your source ?

Hi Matty. There was a guy in Victoria selling ⅜" BSW square nuts (the only size he had), in lots of 50 I think. I'm sure he listed another lot after I bought mine (actually another member in Vic bought them for me and sent them over). ⅜" was just the right size for this post drill. I also needed two 14g CSK woodscrews - and luckily found I had half a dozen 1½" 14g CSK woodscrews in my odds and ends box - 'cause I think buying screws of that size would be difficult these days.

Other post drills have needed 1/2" bolts. For these I cheated. I used M12 bolts and sourced M12 square nuts from a guy in UK (who claims he had them especially made in Germany). I think he was a wheelwright or carriage-maker and needed square nuts, as hex nuts just don't look right on an old carriage.

Cheers, Vann.

This weekend I re-fitted the crank bracket.

First, I cleaned up the two crank bracket bolts. These are 7/16” 14tpi x 1¼” long. They had been quite hard to remove due to rust and dirt in the exposed part of the threads, so I ran a die over the two bolts and shortened them by ⅛”. I don’t believe these are original bolts, supported by the fact that no two are the same.

Bolts.jpg from L to R: auto-feed limiting bolt; column bolt; two crank brackets bolts; auto-feed bracket bolt.

One bolt head clearly says “UNC” and I believe the UNC standard was so named after WW2. The same bolts in a Boynton & Plummer No.1 have square heads.

Boynton & Plummer No1.jpg note the three square head bolts (they hold the crank & auto-feed lever brackets)

If I ever get the rest of this drill back to original I’ll get some square head bolts made.


Due to the very lax standards these are made to (from an engineering perspective), there is a lot of slack in the mounting holes, and as the main casting and crank bracket both support the main crank shaft, it was necessary to do a little aligning.

I loosely bolted the bracket in place and slid the main-crank shaft in. I then jiggled the bracket around until the shaft slid home and turned freely – then tightened the two bolts and re-checked that the shaft still turned okay.

22Jan15HL3.jpg 22Jan15HL5.jpg 22Jan15HL6.jpg

I then removed the shaft again, oiled it, and refitted it, this time slipping the main crank cog into place in the process. Finally I aligned the flat on the shaft with the set screw and tightened the main crank cog in place.

22Jan15HL2.jpg before 22Jan159.jpg after

Next I'll finish de-burring the flywheel shaft and fit it and the flywheel cog.

I have a delay with the auto-feed bracket – there’s a spring retaining pin I need to replace - but hopefully soon (like before the builder and glazier arrive to replace the leaking skylights in the house, 'cause all my spare time will be used helping...).

Cheers, Vann.

Good to see steady progress mate.

In early March the flywheel shaft was de-burred and fitted along with the flywheel cog.

BPfwshaft1.jpg BPfwshaft2.jpg

No aligning was necessary this time as both bearings* are in the same casting (* each bearing being just a hole bored in the cast iron bracket). While the shaft is not perfect, it's not as bad as the exposed left-hand end looks - that's mostly grease and a bit of crud (I had an old rusty flywheel sitting there before I took these photos).

Cheers, Vann.

I needed to find a piece of ¼" rod to replace the spring pin in the auto-feed arm bracket.

BPbrkt1.jpg note the bent pin.

When I did, I found it was loose in the hole. I then needed to decide whether to heat the pin white hot and expand it to fit the hole, or cheat and epoxy it into place. I opted for the latter, as I was scared I might damage the casting, and it would also be difficult to hold and insert the heated pin. But I couldn't locate my epoxy adhesive (I'd loaned it to a friend and forgotten) - hence the break in progress over recent weeks.

Anyway, the pin is now fitted and the bracket painted and ready for fitting.

I'm amazed at the poor standard of workmanship on this drill. The extra heavy iron castings suggest an attempt at a higher quality machine. But when I look at the drilling of bolt holes, I'm shocked.

BPafbrkt2a.jpg
This is the bolt that holds the auto-feed arm bracket to the main frame casting. The bolt hole is drilled and tapped out-of-square by about 5 degrees .

Similarly, the auto-feed pivot bolt in the same casting has it's hole drilled and tapped out-of-square.

BPafbrkt3a.jpg note the new spring pin.

And the fork clamp bolt shows that the fork was also drilled and tapped crooked.

BPfkbrkt4.jpg note the square head on this bolt (which I had made up) has been machined down from ½" to 7/16" square.

All a bit disappointing .

Cheers, Vann.

(and still the glaziers haven't been to replace my skylights)

I've reassembled the auto-feed arm; pivot bolt; limiting bolt; and spring, onto the bracket.

B&Pa:f1.jpg B&Pa:f2.jpg This is the last time you'll ever see that little black bolt.

As the bracket mounts onto the post drill with a single bolt, there's no predetermined alignment, so I decided the bracket needed to go on fully assembled so that I could align it correctly before I bolted it up tight. With everything ready to go I removed the bolt, and took it into the workshop to apply some grease to the threads (I use a special formula consisting of flake graphite & steam cylinder oil - given to me by an old friend long ago - he used it on steam engines). Returning to my post drill I paused to turn on the lights - and promptly dropped the bolt - which fell to the floor behind a cupboard and dropped through a small gap into the cavity between the floor and the ceiling below . Short of removing part of the ceiling it'll have to stay there .

It's 7/16" BSW/UNC - so I'll just pop down to Mitre10 and buy another - yeah right .

Today I was looking through a box of metric coachbolts and idly measured an M12 bolt. Aha, 11.7mm diameter below the rolled thread. 7/16" = 11.11mm. So it was off to Mitre10 after all. I bought a 65mm long M12 engineers bolt, that had a non-threaded portion of over 25mm (as the bolt I need is 1" long). Better still, this one is just 11.40mm diameter. Tomorrow I'll dig out my 7/16" BSW die and cut a new thread.

I might have to file/grind the "M" off the head though, to avoid confusing future post drill fanatics .

Cheers, Vann.

Now if you had thrown the bolt on the floor while aiming at the hole, there is no chance it would have gone in!

Originally Posted by hiroller

Now if you had thrown the bolt on the floor while aiming at the hole, there is no chance it would have gone in!

Yeah, Murphy's Law at its finest...

So to fit the auto-feed assembly. Taking care to turn on the lights first , I offered the auto-feed assembly and replacement bolt to the main frame casting. Then setting the cam at its lowest position, I set the cam follower end of the lever to be clear by a knats.

B&P1.5a:f_assy.jpg This photo staged after I'd tried it out (the limiting bolt is not fully screwed out here)

I then tightened the bolt to lock the assembly in that position, and tried turning the cam. All good. Three notches on the feedwheel maximum (as is claimed by most manufacturers) and the adjustment works to reduce the number of notches as required. Success

Next - clean up the spindle and coupler components.

Cheerio, Vann.

Over the last few days I've cleaned up the spindle; chuck screw; spindle cog key; coupler nut; fibre thrust washer; half-washers; and guide bolt & nut.

CouplerA.jpg CouplerB.jpg Boynton & Plummer No.1½ coupler components.

The coupler nut thread is 1 3/32" dia. (27.65mm) 16tpi. The thread form does not match my Whitworth thread gauge. The guide bolt (anti-rotation bolt) is 3/8" diameter 16tpi (3/8" BSW/UNC). The chuck set screw is 7/16" dia. 14tpi (7/16" BSW/UNC).

Interestlingly the half-washers fit into a groove in the feed-screw and the coupler is fixed to the spindle. This coupler arrangement is the reverse of the coupler on my Dawn No.611 - on the Dawn the half-washers fit into a groove in the spindle, and the coupler is fixed to the feed-screw.

Thrust bearinge.JPG Dawn No.611 coupler components.

On the No.1½ chuck is stamped "3"...

Chuck3a.jpg Chuck3b.jpg

...which matches a similar "3" stamped into the main crank cog...

CC3a.jpg CC3b.jpg

...and another "3" stamped on the main casting (photo too fuzzy to post). I didn't find any other stamped markings on other parts, but I guess this means that these three items belong together.

Today I greased and reassembled the coupler and spindle (another fuzzy photo).

So that's all the original parts I have, de-geased, de-rusted, de-burred, re-painted, re-assembled and lubricated. I now need to select and fit a temporary flywheel. Then it's patterns to make to have the missing parts cast - but that'll go on the back-burner while I finish off the Dawn post drill, and reassemble a bit more of a Silver post drill that's also in the process of being refurbished.

Cheers, Vann.

Looking good.
You have enough variants to be able to design the perfect model from scratch now!