Jump to content

WW1 Thornycroft restoration


Great War truck

Recommended Posts

I have just had a nice weekend in Devon doing lorry things. Father has been busy in the paint shop so we started off by fitting the steering column into place. There was a slight moment of doubt whilst I looked at a pair of shims with no idea of what they were for or even any recollection of making them! Father reminded me and the column was installed.

 

DSCN3691.JPG

 

The next piece was the floor plate.

 

DSCN3692.jpg

 

This was wangled in and the little bent support tags were bolted up making the structure surprisingly rigid.

 

DSCN3695.jpg

 

Then the throttle pivot

 

DSCN3696.JPG

 

followed by the clutch pedal spring anchor. Note the floor support tag on the right. Simple but effective.

 

DSCN3698.JPG

 

Next was the drag link. The socket was greased up. The bolts were adjusted to length, cross-drilled and then pushed through the holes with the shims hung on the other side.

 

DSCN3702.JPG

 

The nuts were tightened up

 

DSCN3705.JPG

 

And then pinned. Much to my surprise, even when done up tight, there was no binding in the ball joint and no back-lash either. Iwas was very pleased with that!

 

DSCN3709.JPG

 

At the other end, the ball cups and compression springs were inserted and the end cover screwed on to tighten them against the ball at the bottom of the steering arm.

 

DSCN3710.JPG

 

DSCN3711.JPG

 

DSCN3712.JPG

 

DSCN3715.JPG

 

DSCN3716.jpg

 

The end cap was tightened until the spring clip popped into the cross hole preventing it from unscrewing.

 

DSCN3717.JPG

Link to comment
Share on other sites

Next came the pedal shaft.

 

DSCN3719.jpg

 

DSCN3720.JPG

 

DSCN3722.jpg

 

DSCN3723.JPG

 

This was quite straightforward although the pedals don't align in their normal positions. Something to be looked at when they are set up. The brake pedal is retained by a steel collar which was missing so I turned on up and it was soon fitted and pinned.

 

DSCN3733.JPG

 

DSCN3735.JPG

 

Finally, the steering wheel was fitted using the nut which Father had just painted black to match the wheel.

 

DSCN3726.JPG

 

Now we not only have a hand brake but we have functional steering as well!

 

A most satisfying day.

 

Steve :)

Link to comment
Share on other sites

The two bolts holding the floor plate to the scuttle through the newly made bent sections, have round heads. I could not tell if they were rivets otherwise. That is looking over the one here.

One for the rivet counters!

Doug

Link to comment
Share on other sites

A great step forward, Steve. Doesn't it give you a thrill when your restoration job starts to go back together and look like a truck once again.

Regards Rick.

 

1916 Albion A10 Chassis No. 361A

 

Hi Rick.

 

Yes, immensely satisfying! We spend ages pottering along with no visible progress and then there is a sudden step change!

 

We are, of course, doing lots of little bits all at the same time so we end up with gaps in the narrative. Sorry about that, I'll try to post some more shortly!

 

Steve :-)

Link to comment
Share on other sites

The two bolts holding the floor plate to the scuttle through the newly made bent sections, have round heads. I could not tell if they were rivets otherwise. That is looking over the one here.

One for the rivet counters!

Doug

 

Thanks Doug. Every little gem of information is valuable. I suspect that there are only really two rivet counters for J-types, you and me!

 

Steve :-)

Link to comment
Share on other sites

As I have said, we usually have several things on the go at once and one of them is the hand throttle quadrant to mount on the steering column. (The lad in the picture is the grandson of one of the Carlton Colville museum volunteers who kindly let us in.)

 

IMG_5405.JPG

 

IMG_3688.JPG

 

As you can see, this is a casting and patterned on both sides. I was puzzling over this one until young Will kindly offered to model it for me in 'Solidworks' CAD software so that it could be 3-d printed. He sent me this rendering of it and it was almost spot on.

 

!cid_6a7a133f-8d2d-b0d5-ccb6-d3620d1a5053@yahoo.jpg

 

His Dad had a final tweak of it before I emailed it to Barry who has a suitable printer (A Christmas present from his good lady I believe!) and he printed it.

 

!cid_X_MA1_1493411070@aol.jpg

 

Unfortunately, it is stepped underneath and the printer, which operates like a very fine glue gun, had nothing to lay the bead on. To get around that, he laid up a fine structure to start it on with the intention of breaking it off afterwards.

 

!cid_X_MA2_1493411070@aol.jpg

 

This worked up to a point but the surface it left behind was not really good enough.

 

!cid_X_MA3_1493411070@aol.jpg

 

He had another tweak of the model to make it in two pieces which could then be bonded together afterwards.

 

Barry 5.jpg

 

Barry 4.jpg

 

This was much more successful.

 

!cid_X_MA1_1493930122@aol.jpg

 

Two coats of 'pattern coat' and it was ready to go.

 

DSCN3673.jpg

 

DSCN3672.jpg

 

Father took it to the foundry yesterday so we will see what they make of it. That's one more down and twelve to go!

 

You can't do this hobby without your friends. Thanks Chaps!

 

Steve :-)

Edited by Old Bill
Link to comment
Share on other sites

We have been thinking about how we are going to put the fuel tank together as it is of riveted and soldered construction, the same as that for the Dennis. I managed to make up a rivet squeezer for the Dennis by making some adaptors for the jaws which worked quite well. However, quite out of the blue, Andy very kindly offered me the use of his squeezer which offer, I have gratefully accepted. This one started life as a basic hydraulic cable crimper.

 

DSCN6530.JPG

 

However, Andy has converted it by making and arm and adaptor to carry rivet snaps.

 

DSCN6469.JPG

 

It has proven successful but, unfortunately, the anvil, made from an M12 grub screw, broke out of the side and was repaired by welding. This had the effect of jamming the grub screw so, with Andy's permission, I cut the end off and had a block welded on by our senior welder at work.

 

DSCN6470.JPG

 

This was done using the TIG process and came out well.

 

DSCN6528.JPG

 

My next challenge was to drill a new hole for the anvil, in line with the centre of the thread. To centre it, I machined a close fitting boss which I bolted to the milling table. I then clocked it in line with the quill and locked the table. Then it was simply a case of dogging the arm down and drilling through.

 

DSCN6531.JPG

 

DSCN6532.JPG

 

I tried a different concept this time in that the hole is only 1/4" dia so the anvil bears against the face of the arm and is only located and secured by the centre stud giving a solid surface to push against.

 

DSCN6533.JPG

 

All ready to go once the wrapper is bent up.

 

DSCN6534.JPG

 

Bending the wrapper is a bit of a challenge. There is one 3" radius, two at 2 1/2" radius and one at 1" rad. The rollers at the railway are 4" diameter and long enough so we should be able to do three of the bends there. However, the 1" rad is a bit more challenging. I have determined to push it into a vee-block using a piece of tube. As the material is quite thin, I think a wooden block should suffice so I have made one up from timber lying around.

 

DSCN6551.JPG

 

DSCN6552.JPG

 

Tim then came up with a piece of scaffold tube 44" long. The tank is 40" so this is just right. It is also 1 15/16" diameter so it is perfect that way too! Here is the final assembly.

 

DSCN6553.JPG

 

All ready for the next step!

 

Steve :)

Link to comment
Share on other sites

Look what we've got! Father has been to the foundry today and picked the quadrant casting. It has come out really well so it only remains to give it a bit of a clean up and drill two holes. One more down!

 

DSCN3781.jpg

 

DSCN3782.jpg

 

DSCN3783.jpg

 

The foundrymen were very impressed with the pattern. Thanks for that Will, Adrian and Barry for the team effort!

 

Steve :-)

Link to comment
Share on other sites

More pattern making going on. On the scuttle, on each side there are the supports for the cab hood frame. These are cussing awkward castings! They are thin, radiused and are set back as well!

 

IMG_3649.JPG

 

IMG_3651.JPG

 

After some head scratching I thought that I could assemble them from some sheet MDF and strip mouldings to get the internal radii. I had drawn them up long ago so at least I knew what I wanted to achieve.

 

DSCN6473.JPG

 

DSCN6476.JPG

 

DSCN6478.JPG

 

The outside radius was relatively straightforward and achieved by gentle use of the plane on the outside of the moulding.

 

DSCN6479.JPG

 

Then I had to set the angle. I sanded it to the right angle best I could and then cut some ash strips to brace up behind.

 

DSCN6486.JPG

 

DSCN6487.JPG

 

DSCN6501.JPG

 

Blocks on the end, made from recycled mahogany, were glued to the ends.

 

DSCN6508.JPG

 

These were then shaped using the Dremel and the ribs were cut back using Grandfather's spoke shave. He was a shipwright by training and I would like to think that he enjoys seeing his tools loved and used.

 

DSCN6512.JPG

 

DSCN6513.JPG

 

Time to cut the aperture. These were drilled at the corners and then profiled with a coping saw before finishing with glass paper.

 

DSCN6515.JPG

 

A bit of filler.

 

DSCN6517.JPG

 

Ready for paint.

 

DSCN6518.JPG

 

DSCN6520.JPG

 

The usual two coats of Bondaprime with a polish with steel wool.

 

DSCN6538.JPG

 

A trial fit.

 

DSCN3729.JPG

 

DSCN3728.JPG

 

New castings, picked up yesterday!

 

DSCN3786.jpg

 

Only ten more patterns to do!

 

Steve :-)

Link to comment
Share on other sites

Steve,

 

A very nice pattern ( .....for a dinosaur )! Equally impressive though was the superb thin wall casting. Bridport really do seem to do a lovely job on little one off's where there cannot be too much money to be made.

Link to comment
Share on other sites

Those brackets illustrate perfectly your incredible attention to detail: making patterns and having castings made to perfectly replicate the original, where lesser men (myself included) would have just cobbled together something that looks something like it out of some steel angle and bits from the scrap bin. Nice work.

Link to comment
Share on other sites

Those brackets illustrate perfectly your incredible attention to detail: making patterns and having castings made to perfectly replicate the original, where lesser men (myself included) would have just cobbled together something that looks something like it out of some steel angle and bits from the scrap bin. Nice work.

 

Thanks! :D

Link to comment
Share on other sites

Steve,

 

A very nice pattern ( .....for a dinosaur )! Equally impressive though was the superb thin wall casting. Bridport really do seem to do a lovely job on little one off's where there cannot be too much money to be made.

 

Yes, it is nice to have a sympathetic foundry so close to home.

 

The printed pattern has produced a super result and we are very pleased. It is a very good way to go. However, I will continue with wood patterns because I can do them myself without imposing on anyone. The 3d printer is a specialist bit of kit which I shan't invest in for ourselves and I certainly don't want to get into the situation where whenever I contact someone, the first thought is. 'Oh no, what does he want this time?' Mind you, the prop shaft spiders might suit this process very well! ;)

 

Steve

Link to comment
Share on other sites

Whilst it's not cheap, there are commercial printing services; e.g. http://www.shapeways.com. You upload the model, they print it in your chosen material and post you the part. I used this to make a pattern for a works plate for the Garrett trailer to go with our wagon. The pattern cost something in the range of £15, I think!

Link to comment
Share on other sites

The printed pattern has produced a super result and we are very pleased. It is a very good way to go. However, I will continue with wood patterns because I can do them myself without imposing on anyone. The 3d printer is a specialist bit of kit which I shan't invest in for ourselves

 

They have become very affordable, this is the one I have:

http://www.ebay.co.uk/itm/CTC-3D-Printer-Dual-Extruder-MK8-Factory-Direct-Lowest-Price-ABS-PLA-/221783391069?hash=item33a351fb5d:g:b60AAOSwBs1XMZXh

Link to comment
Share on other sites

Steve,

I have been following this restoration for some time and the work done is absolutely amazing, and I would like to thank you for all the updates with pictures, most interesting and usable for other restorers as inspiration. I also try to spread it to my friends to have a look when they have lost their enthusiasm.

 

One question - all these bits that you have made new by casting, were they originally casted? Not drop forged?

I am not an expert, but sometimes I find it difficult to see if an old rusty part is forged or casted.

From what I learned during my time studying to engineer, drop forged is a lot stronger than casted, but it is also a matter of alloy being used.

It would be of interest to know your opinion on this and what you have found out during the restoration.

 

As the director of the Swedish Tank museum I sometimes have to wear a tie, but most of the time I have dirt under my fingernails due to tank and vehicle restorations in my spare time.

Now we have recieved the new track pins for our WW I LK II project so now we can continue with the tracks.

http://blog.arsenalen.se/en/

 

 

Stefan Karlsson

Link to comment
Share on other sites

Steve,

 

One question - all these bits that you have made new by casting, were they originally casted? Not drop forged?

I am not an expert, but sometimes I find it difficult to see if an old rusty part is forged or casted.

From what I learned during my time studying to engineer, drop forged is a lot stronger than casted, but it is also a matter of alloy being used.

It would be of interest to know your opinion on this and what you have found out during the restoration.

 

As the director of the Swedish Tank museum I sometimes have to wear a tie, but most of the time I have dirt under my fingernails due to tank and vehicle restorations in my spare time.

Now we have recieved the new track pins for our WW I LK II project so now we can continue with the tracks.

http://blog.arsenalen.se/en/

 

 

Hi Stefan.

 

Pleased to hear that you find it useful!

 

The castings we are making are are direct replacements for castings we don't have. A lot of them could be fabricated but whilst I can make patterns, I can't weld so casting is my preferred method. Of course, we try very hard to produce bits in the same way as they did 100 years ago and castings were much more common then anyway. When we find forgings, we usually replicate them by fabrication or carving out of the solid but we have been generally fortunate with the Thornycroft in that there aren't many and the critical ones we have. The only place where I think we have used a casting instead of a forging is the drag link ball end. This is a critical component. However, when the lorry was built, only grey iron would have been available but we have been able to use SG malleable iron which is very much tougher. There have been one or two raised eyebrows but I am sure we will be fine. No doubt time will tell!

 

One item I am pondering over at the moment is the propshaft end. This is the one at Carlton Colville:

 

DSCN0434.JPG

 

It is brazed to the drive tube but is it a forging or a casting? If it is a casting, is it iron or steel? We don't have one so we are going to have to make a replacement. My guess is that it is a steel casting but they are difficult to get so I am wondering whether we can get away with an SG iron casting. Please may I have some views? SG iron is easy to get so I would really prefer to go that way if we can!

 

I am enjoying your tank project. Do keep us posted with progress!

 

Steve :)

Link to comment
Share on other sites

I would be quite happy with it as a SG iron casting. If you feel that it is marginal then it could very easily be made a little heavier than original without it looking wrong. I would think that the rim is most likely to fail and is key to preventing the spokes being twisted by the cantilevered load of the bolts attaching the rubber coupling. I think that the loads are not really 'shock' loads as the rubber coupling must give some cushioning effect and of course the original bolts were not of very high tensile material or very large diameter and I would have seen them as the weakest link.

 

Just my gut feel

 

David

Link to comment
Share on other sites

Is a SG iron casting going to be any weaker than the flexible disk behind it, I very much doubt it? However would it not be better to spend a day with your friends big lathe and turn it from a solid lump of steel. You could then mill the slots in (Preferably on your other friends CNC machine) and spend a little time fettling the radii of the slots with a file. Easy!

Barry.

Link to comment
Share on other sites

Actually not that easy to get the shapes of the raised bosses for the three bolts where they blend into the trumpet shaped curved 'spokes'. This will require some care to carve out of a wood / MDF pattern but to get them right in mild steel would be a challenge, particularly as the turning operation would leave a considerable amount of material to be removed by hand / angle grinder. If you earn your living programing a CNC universal mill it would be possible to get the shape with a ball ended cutter but that would involve some complex programing and the right contacts.

 

Alternatively it would be possible to machine the bosses as simple cylinders (I guess they are roughly 1" diameter and length) and weld them into machined holes in the spokes with a big weld fillet on both sides. Cleaned up by hand the welds could look ok but there would be quite a lot of seperate machining operations, weather manual or CNC with a vast amount of metal turned to swarf unless the tube that brazes to the prop shaft tube, the spokes, and the rim are each seperate pieces all welded together.

 

As the idea is to reproduce what was originaly a casting and Steve is getting really good at pattern making, I think that a casting would be the way to go.

 

David

 

PS, just realised that I did not address the question of; is the original a casting or a forging?

 

I very much doubt that it is a forging as the combination of the bolt hole bosses, the generally thin tubular sections and the holes between the spokes would together have made forging difficult. Forging is much more suited to 'lump' shapes like gear blanks and things that will form without the material needing to flow too far from the original red hot billet, as in con rods and crankshafts. Although this is a critical component in that it must not fail, it is not that highly stressed, being driven by a rubber disk via three smallish bolts, so a casting would be fine.

 

When this truck was built it was much harder to machine things to shape than to cast or forge things, so every effort was made to avoid machining to shape if possible. The machining was seen as very much a finnishing operation to give exact dimensions and surface finnish. Thus it would have been far more trouble than it was worth to either mill out or punch out the holes between the spokes in this component compared to casting them in which is easy. So the fact that they chose to include holes points to castings.

Edited by David Herbert
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...