WW1 Thornycroft restoration

[simon king]

Could you not have used a 1" hole saw to make the hole for the bracket, rather than having to chain drill and file

[Tomo.T]

Hi Tim,

 

Good to meet up the other night. Is it possible that Thornycroft had more than one type of lamp bracket for the J type? I have seen a variation where the bracket is fixed to the chassis by two bolts arranged vertically. This version had the headlamps sitting in a yoke about level with the radiator brush bar. I would have posted a picture but had to give up due to incompetence.

 

Regards,

Tomo

 

I may have answered my own question. The J type I was looking at was the Hampshire Museum one. I suspect it may be sporting civilian lamp brackets fitted when it returned after the war ?

[nz2]

The position of lights on Thornycroft's appears to vary with the times. Aside from those with no lights at all, various photos show others with lights on the scuttle, and as you illustrated, mounted beside the radiator. There appears to be a series of different mounts, ranging from a flat plate bolted in place similar to the mud guard mount. Two positions appear one in a vertical side of the chassis rail, the other on the top of the rail. Another photo shows a u bolt about the chassis dumb irons area. Yet another shows the threaded mount in the area of the radiator protector upright section, sharing a common bolt hole.

My 1912-13 chassis has bolt holes on top of the chassis rail, with no holes in the side rails for a radiator protector.

The 1920's chassis has holes also on the top of the rails and on the sides. Nothing approaching 1 inch in diameter.

Without an accurate dated illustrated parts list of the war era to work from it appears to be the restorers choice.(manuals so far located all are post 1918)

Doug

[Old Bill]

I may have answered my own question. The J type I was looking at was the Hampshire Museum one. I suspect it may be sporting civilian lamp brackets fitted when it returned after the war ?

 

The Hampshire Museum lorry has a lot of new metal in the chassis as it was totally rotten when removed from the scrap yard. I am pretty sure that the side rails were fabricated from scratch and welded along the bend lines. If there were no brackets with it, Ron may well have fabricated brackets to carry the lamps rather than replicate the originals.

 

Steve

[Tomo.T]

Steve, that explains it, thanks. The lamp brackets on the Hampshire J type do resemble the ones on a post war Thornycroft in the same collection ! They are taller and less sturdy than the military type(s) which were obviously intended to keep the lamps tucked down out of harms way.

 

Doug, This is clearly a can of worms ! I am all for restorers choice !

 

Regards,

Tomo

[GeePig]

Well, whatever the choices, at least you are remaining true to the vehicle that you started with

 

trevor

[Asciidv]

Could you not have used a 1" hole saw to make the hole for the bracket, rather than having to chain drill and file

 

I think only a carbide tipped 'Rotabroach' would have been suitable for this job rather than the cheap hole saw cutters you generally see.

 

 

However the existing offset hole would have probably damaged the teeth of even a Rotabroach so I am almost sure that Tony used the best method. Also you just have to admire the roundness of the hole and beautiful parallel sides to see that a true craftsman did the job!

[simon king]

Thanks - another bit of useful information stored away for future use

[andypugh]

I think only a carbide tipped 'Rotabroach' would have been suitable for this job!

 

I don't think that it would need to be carbide.

I have used ordinary HSS Rotabroach cutters for birds-mouthing thick-walled tubes, so I am pretty sure that one woud have worked here.

 

With that job to do I would have relished the opportunity to realise a long-held ambition to own a mag-base drill.

 

But, failing that, with the guide plate I am sure that a Rotabroach cutter held in a normal drill would have worked.

 

http://www.ebay.co.uk/itm/Rotabroach-Type-Mag-Base-Cutter-Hole-Cutters-Annular-1-50mm-LOC-/262241740348

 

If there is any likelyhood that you will be wanting to drill in-situ holes in chassis frames on an ongoing basis then I would strongly suggest keeping an eye out for a nice little mag-base drill.

[Citroman]

In my uncles steel company they had portable drill presses that had electro-magnetic feed so it could be hooked up in every angle on to a steel beam to drill. Would have been usefull here too :-)

[David Herbert]

In my uncles steel company they had portable drill presses that had electro-magnetic feed so it could be hooked up in every angle on to a steel beam to drill. Would have been usefull here too :-)

 

In the UK these are often referred to as Mag - Drills.

 

I agree with Andy that an ordinary HSS Rotabroach type cutter is quite happy to cut a partial circle but you must go very gently, especially at the start. It is after all just a hollow end mill really.

 

I am not sure about the idea of driving them with an "ordinary drill" though. An ordinary bench mounted drill press - yes, but a hand held drill is very hard to hold steady enough and although these cutters will drill hundreds of holes without sharpening they won't survive shock loads. It is just too easy to break them, particularly as they break through at the end.

 

David

[Minesweeper]

Interesting that cutting these holes has caused so much interest! I am no Engineer or Fitter or Machinist and in my simple thinking, there was no other way of getting these holes in the correct place other than by the method that I used. Access to the job was very limited in any case - unless the front wheels were taken off again so that I could more easily get in there - and I certainly was not going to do that on my own!

 

Tony

[Ted170]

It's just two holes, any simple approach is good And the one seen here is not the most simple, but very efficient. Great work, as always!

[David Herbert]

I agree with you Tony. Even though I have a mag drill, I would have done it the way you did because there was a very limited area to 'stick' a mag drill to, and that is not very flat. usually you would get round that by clamping a bit of steel plate on to give you a firm base but in this case the rivet heads would be a problem. As I said in my post above, trying to use a hand held power drill with a rotabroach type bit would most likely result in breaking the bit (particularly with the other hole overlapping). A bunch of 1/4" holes followed by a file doesn't take that long anyway.

 

But the job got done, some more bits bolted on .

 

David

[steelman]

I am absolutely amazed at the quality of the work folks perform and report on this site. You are true craftsmen. I am an Engineer and own a steel fabrication shop here in the US. We have mag drills, cnc drills, hydraulic punches and just about anything we need to do our work accurately and quickly. Occasionally, we have found it necessary to use a thick plate drilled to the size hole we wish to make, clamped it to the object we wish to drill, and use a hss rota broach bit with a handheld drill to put the hole in steel that couldn't be done otherwise. The thick plate serves as a guide to steady the bit from wobbling. I agree carbide may Crack and shatter unless held perfectly still, where as hss bits are more forgiving. Having said this, my hat is off to you for a job well done!

[Great War truck]

Progress has been noticeably slow of late because of other unavoidable obligations which have held us up – but some work has still been going on! The Headlight Brackets have now been fitted and two unrestored Miller Lamps trial fitted confirm that they are satisfactory.

 

We found an acceptable Supplier for the 125 Radiator copper tubes and the 18,000 Gills that we require and they have been ordered – it will be about a month before they are received. We have to thread the Gills on the tubes ourselves after which they will then be sent back to their supplier for solder dipping. All part of the agreed deal.

 

Good friend, BH has kindly offered to machine the top and bottom brass plates of the core on his CNC Mill so that they will be completely ready to accept the “Gilled tubes” for the final assembly of the core. Those brass plates must firstly be used as templates to drill the bolts holes in the flanges of the top and bottom tanks, so that everything will be ready for bolting together when they are finally offered up to each other.

 

Tim came down to Devon for a couple of days last month with the intention of joining Tony in stripping down the Scuttle and its fittings ready for sand blasting and then painting but his visit coincided with a major storm which took a large Apple Tree down at Tony’s and the time intended to be spent on the Scuttle was used instead in “logging” and clearing the Apple Tree. Yet another diversion. The Scuttle is being given priority as we shall need that when the Radiator goes on as there is an essential supporting brace for the Radiator from the Scuttle.

 

We hope that progress will speed up now!

[flandersflyer]

I don't think that it would need to be carbide.

I have used ordinary HSS Rotabroach cutters for birds-mouthing thick-walled tubes, so I am pretty sure that one woud have worked here.

 

With that job to do I would have relished the opportunity to realise a long-held ambition to own a mag-base drill.

 

But, failing that, with the guide plate I am sure that a Rotabroach cutter held in a normal drill would have worked.

 

http://www.ebay.co.uk/itm/Rotabroach-Type-Mag-Base-Cutter-Hole-Cutters-Annular-1-50mm-LOC-/262241740348

 

If there is any likelyhood that you will be wanting to drill in-situ holes in chassis frames on an ongoing basis then I would strongly suggest keeping an eye out for a nice little mag-base drill.

 

 

yep.

 

plenty of water on it during cutting...at a slow, steady speed with a steady pressure applied during cutting

 

L. S. STARRETT make what I consider to be the best holesaws....I use em regularly to cut out holes for downlights (I`m an electrical contractor)

 

DART are good n all..

[Great War truck]

We have been looking through our lamps to find a pair of P & H side lamp. We found three in need of some work and one oddity.

The odd one is made by the Economic Car Light Co London:

Which I have never heard of.

I wonder if it was a post war surplus lamp dealer and they took off the Miller or P&H badge and refurbished the lamp for resale. Anyway, it will not be much good as it has a bit of rust on the back:

But on the plus side we did get a couple of good bits off it:

Most notably the glass which is in super condition.

[Ex-boy]

Not being familiar with vintage lamps, I need to ask if the lamp glass is just a thin, curved piece or a solid lump with a flat base. I ask because sitting there on the newspaper, it looks just like two glasses I have in my workshop, the origins of which I have no idea. One is 3 inches diameter, the other 13 cm. and they are both solid, with a flat side. The smaller one has a few minor chips on the edge and the bigger one has a larger chip, also at the edge.

 

If they are any use to you, they are yours for the asking. I will even post them for no charge, for all the enjoyment this thread (and others) have given me.

 

Regards,

 

Steve.

[Bob Grundy]

 

In the early part of this century I was asked to give an opinion on this Thornycroft which was south of Widnes. Does anyone know its fate ?

[ploughman]

Not being familiar with vintage lamps, I need to ask if the lamp glass is just a thin, curved piece or a solid lump with a flat base. I ask because sitting there on the newspaper, it looks just like two glasses I have in my workshop, the origins of which I have no idea. One is 3 inches diameter, the other 13 cm. and they are both solid, with a flat side. The smaller one has a few minor chips on the edge and the bigger one has a larger chip, also at the edge.

 

If they are any use to you, they are yours for the asking. I will even post them for no charge, for all the enjoyment this thread (and others) have given me.

 

Regards,

 

Steve.

 

Very similar glass lens' are used in old railway handlamps.

[Great War truck]

Not being familiar with vintage lamps, I need to ask if the lamp glass is just a thin, curved piece or a solid lump with a flat base. I ask because sitting there on the newspaper, it looks just like two glasses I have in my workshop, the origins of which I have no idea. One is 3 inches diameter, the other 13 cm. and they are both solid, with a flat side. The smaller one has a few minor chips on the edge and the bigger one has a larger chip, also at the edge.

 

If they are any use to you, they are yours for the asking. I will even post them for no charge, for all the enjoyment this thread (and others) have given me.

 

Regards,

 

Steve.

 

Thank you Steve

 

That is very kind of you and yes please we would love to have them. I will send you a PM with my address.

Thanks

Tim

[Great War truck]

[ATTACH=CONFIG]113587[/ATTACH]In the early part of this century I was asked to give an opinion on this Thornycroft which was south of Widnes. Does anyone know its fate ?

 

That's interesting. It is a post war one disguised to look like a wartime one. It is now being civilianised and it is the one that was in Downton Abbey

 

https://www.youtube.com/watch?v=Wz2O1milqMI

 

Not that I have ever seen a single episode you understand. I was told the driver was given directions to "just drive down that road at a gentle 30mph!".

[Great War truck]

My sincerest thanks to BH for undertaking and then explaing the next step.

Steve abandoned his traditional pencil and paper to draw the radiator top and bottom plates in 'SolidEdge'. This is 3D CAD modelling programme, so that once the basic drawing is complete a rendered image of the completed parts is only a mouse click away. The drawing process is very simple. A sketch is first created without any dimensions and these dimensions or 'parameters' are added later. The sketch automatically adjusts as more parameters are added.

A CAD drawing was required so that it could be machined on this CNC milling machine. This machine has glass slides on all 3 axes and is capable of positioning to 1 micron (one twentieth of a 'thou) under stable temperature conditions.

The first task was to clamp the 3/8" brass plate to a sacrificial bed plate and drill some holes through which it will be bolted down.

With the plate bolted down we are now ready for the machining operations.

The first operation is to pre-drill the plate for the tubes and the bolt holes around the periphery where the plate bolts to the tank flanges.

The final holes are not drilled, but cut to size using a milling cutter and a process called circular interpolation. Here the milling cutter traces around the inner diameter of the circle. This means that any size of hole can be produced with one size of cutter. For the radiator tubes we requested an offset of 0.01mm from the nominal size so that the tubes would be a snug fit, but not overly tight.

The final finished plate. It looks almost as real as the rendered image!

[Old Bill]

We couldn't do this without the kindness of our friends and this is amazing. Thank you, Barry, for speeding us on our way!

 

I ordered the tubes and gills last week and they should turn up within a month. Then we will have the fun of threading them on before sending them and the plates off for soldering. Once we have the radiator, the lorry will have a face. Progress is being made!

 

Steve