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1914 Dennis Lorry


BenHawkins

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I assume the plan isn't to pop-rivet the gearbox and braces together, so what is the plan?

I am making this up as I go along but for the rear brace I plan to drill through the vertical faces of the casting and bolt through to the braces this way.

 

The front pair will be much more of a challenge. There is a reasonable amount of the nearside mount remaining but the offside one is completely missing. This will probably involve fabricating a copy of the missing mounting, then trying to weld it to the existing casing. For this brace I think I will resort to bolts through the case to the inside of the gearbox as well (making sure I position them to miss the gears).

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I have been working through the stock of parts today and trying to work out what materials I need to get in to keep me busy for the next couple of months.

 

The plan for the steering box brackets is to use more laser cut parts. The alignment of the steering wheel is dimensioned on the general arrangement drawings so we packed the box up to the right height and took the required dimensions.

 

There is a bracket that hold the top of the steering column to the bulkhead. The Goslings had given me most of this bracket (thanks!) but it didn't come with the clamp that goes around the column. I had parts laser cut before but they needed bending.

IMG_0571s.jpg

 

One blank and one bent.

IMG_0568s.jpg

 

Unfortunately I got the geometry slightly wrong and it needs a piece of cardboard to make it clamp up. It will get modified this week to make it clamp the column properly!

IMG_0573s.jpg

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Just a note about the potential for corrosion to set up between the ally gearbox and replacement steel gearbox mounts. I'm sure you are aware of this issue, but just in case it is well worth applying something to stop this from happening. There are special paints available to keep the two separate (can't remember the name off hand) but I have used on more modern stuff on assembly lines for the same reason.

Regards.

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The front pair will be much more of a challenge. There is a reasonable amount of the nearside mount remaining but the offside one is completely missing. This will probably involve fabricating a copy of the missing mounting, then trying to weld it to the existing casing. For this brace I think I will resort to bolts through the case to the inside of the gearbox as well (making sure I position them to miss the gears).

 

It might be better to leave it as an "honest repair" with just the steel frame not disguised by aluminium (which is unlikely to be particularly structural, even if welded on)

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Just a note about the potential for corrosion to set up between the ally gearbox and replacement steel gearbox mounts. I'm sure you are aware of this issue, but just in case it is well worth applying something to stop this from happening. There are special paints available to keep the two separate (can't remember the name off hand) but I have used on more modern stuff on assembly lines for the same reason.

Regards.

 

While correct with the alloy being the sacrificial anode , that will have already happened as the gears, shafts, selector forks etc are all steel. The very brittle nature of the alloy and its powdery external surface is a good indicator of the electrolysis in action. There for the condition of the gears and shafts inside should be good, aside from wear from use.

The construction of these mounts could well be a gain to the strength of the gearbox as the alloy weakens and crumbles over time. Is this therefore prevention or cure?

The other way would be to construct the frame work out of alloy. Still a variation occurs in conductivity, as the original alloy casting contains some manganese.

Doug

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Oh how I wish that the LFB hadn't specified brass radiators for fire engines....

I think the best radiators are the ones with cast gunmetal top and bottom tanks. The sheet brass ones suffer from leaks from the many feet of soldered joints. The aluminium ones corrode everywhere they are in contact with the core.

 

The issue of gearbox corrosion at the interface between box and the new steel brackets is certainly a concern. I may investigate blasting the steel brackets and metal spraying them with aluminium. Whatever happens when I fit them it would seem sensible to seal the seams so that water does not get into the crevices.

 

It has been a week of mainly finishing off small jobs. The first was to cut a section out of the steering column clamps and weld them back together so they would then fit properly.

IMG_0592s.jpg

 

I made most of the shackle pin greasers many months ago, so I have finally finished the job by making the last four.

IMG_0590s.jpg

 

The steering wheel had a couple of coats of thinned varnish and then a further coat. When it hardens off I will rub it back and give it at least one more coat.

IMG_0591s.jpg

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Andy Pugh dropped off his rivet squeezer before Christmas. As my rivets have arrived I had to give it a go.

IMG_0578s.jpg

 

It certainly should be better than setting several hundred rivets with a ball-pein hammer!

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It then seemed like a good idea to fit the central bonnet rest.

IMG_0593s.jpg

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There was enough time to look at the front bracket as well. My profiles were not quite the right shape so I had to grind them back a bit to get it all to fit. It took a length of channel and many clamps to get it all to line up properly so I could tack it together.

IMG_0584s.jpg

 

Then removed it to weld the other side (using one of the other profiles and a clamp to keep the sides the correct distance apart.

IMG_0586s.jpg

 

This photo shows how much is missing from the gearbox. On the left I can probably get a couple of holes into the remains of the flange you can see. On the right I will have to drill into the box but I have not worked out exactly where yet.

IMG_0595s.jpg

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And I thought our gearbox was poorly! At least we had something to bolt to!

 

When we bolted, it took a lot of care to miss the gears with the internal bolt heads. We also took the opportunity to drill the bolts and split pin the nuts as these as loose items in the box would not be good news.

 

How do you do it Ben? No one would believe that you actually go to work!

 

Steve :D

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Thanks Steve,

 

Work and a trip to London have got in the way of progress slightly this week but I was able to borrow the press again in London. At the start of the week I picked up another "minimum order" of laser cutting; another pair of bonnet sides at these bits. Some parts are for the 1908 and just included for making up the numbers.

IMG_0602s.jpg

 

And my steel order was ready at the end of the week. This includes material for the rear universal joint, propshaft, gearbox selector rods, radiator tie rod and front wing brackets.

IMG_0604s.jpg

 

The first job was to fit a peg to one of the laser cut profiles so I could remove the stubborn gearbox selector rod glands.

IMG_0597s.jpg

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I had some issues with pressing the bonnet side. You may remember that the laser cutters had pierced within the body of the panel to cut the slots on the last pair I had made. When we pressed in the louvres this very narrow slot opened up. I asked them to avoid this on the new pair. However this then meant the panel split at the ends of the louvres.

IMG_0610s.jpg

 

Some modification to the tool (increasing the radius) and lengthening the slots by about 1mm with a hacksaw blade resolved this.

 

During the week I drilled for the bonnet catches and today I have been able to rivet the various parts on. The vertical bits

of brass trim are just in place with screws until I get the hinges sorted out.

IMG_0613s.jpg

 

The hinges are made of a number of brass sheet formed into a P shape.

I am not sure how well they will work but I had some tooling made for the hinge pieces made in the batch of laser cutting. My plan is to start with rectangles of brass sheet and fit them in the slot in this:

IMG_0607s.jpg

Then after putting a radius on the front of the T shaped piece I should be able to press the brass rectangle through the rectangular hole to make it U shaped with unequal legs.

 

If that works then the next part of the plan is to put the U in this jig.

IMG_0608s.jpg

With a piece of 3/8 steel rod through the hole I hope to be able to press this T shaped tool down onto the brass and close the U up into a P. Hopefully I can then remove the steel rod and extract the brass P.

 

If I get it right first time I will be amazed!

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I like your hinge making tools. A few comments that I am sure you already thought of or would do by yourself !

 

On the first opp. tool you could radius the edges of the hole and lightly lubricate them to ease the movement of the brass over them. Also a stop to position each brass blank in exactly the same place - then there would be no need to start the bend as a seperate opp. and they should be more uniform.

 

On the seccond opp. tool you may need to clamp the long leg of the brass to the tool to stop the 'U' being pulled around the pin as you press the short leg. Practicing with bits of scrap should get the right bending allowance in three goes or two if you are very good. First go would just be flash ! You might find that the spring back of the brass is enough to need a rather smaller pin than the final hinge pin diameter.

 

Good luck and I look forward to seeing how it works out.

 

David

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Thanks for the comments on the hinge tool. I had visitors today but did manage to give it a try.

 

The first tool is has the slot offset to hopefully put the bend in the correct position. I had already used a file to radius the edges to make sure the brass would bend rather than cut.

IMG_0621s.jpg

 

The tool would then also work as a gauge to make sure I had cut the brass to the correct size.

IMG_0622s.jpg

 

I welded some rod to the other part of the first tool to achieve the radius on the leading edge.

IMG_0623s.jpg

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The piece of brass then fitted into the second tool.

IMG_0629s.jpg

 

Then pressed again.

IMG_0630s.jpg

 

So fairly successful. I didn't achieve a 90 degree bend in the P so the legs do not quite line up, the simple solution to this would be to cut the brass blanks slightly shorter or trim them to line up after pressing.

IMG_0633s.jpg

 

I will probably make three more like this to see how the clearances on the hinge pin feel.

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I picked up the castings for the water jacket tops on Tuesday.

IMG_0616s.jpg

 

There was just enough time to roughly skim the faces parallel on one of them.

IMG_0638s.jpg

 

Also I welded some of the laser cut profiles together to make a bracket for the steering box. This will need a little more tidying up before I blast and paint it.

IMG_0639s.jpg

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The handbrake/gear change assembly needed modifying with the new laser cut profiles but also needed some curved bits of steel. In my stocks I found a piece of bar of the correct radius that I could use to press the curve.

IMG_0618s.jpg

 

I then cut sections out and welded them in.

IMG_0619s.jpg

 

Now it is fully welded and the welds ground flush I can blast and paint it.

IMG_0634s.jpg

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Although there has just been one folding operation prior to the pressing of the 'P' I woudn't underestimate the gains that might be achieved by annealing between the two operations. It would also be nice to make a third tool and punch in the rivet holes too!

 

Barry.

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Annealing the brass strips after the first operation would probably allow me to close up the diameter further. Another variable to try out.

 

I had a couple of work day trips and was otherwise occupied today but I still managed a few tasks!

 

Using the milling machine I faced the top of the second water jacket.

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Then as it was difficult to hold in the vice to machine the bottom I used the surface grinder as it has a magnetic table.

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This gave me flat faces I could work from to mark out where I wanted to put the holes. One of the difficulties of working with castings is finding the part you want within them, it is quite easy to start machining and then find there is not enough material left where you need it.

IMG_0643s.jpg

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After centre punching I started the holes with a centre drill.

IMG_0645s.jpg

 

The big hole was made by working my way up through cutter sizes.

IMG_0646s.jpg

 

Then after the other drilling and tapping operations I tried a first fit. They need machining down a little and hopefully I can get that done over the next week.

IMG_0652s.jpg

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The weather was nice again yesterday so I spent it in the yard welding again.

 

For the front gearbox bracket the base of the gearbox has a complicated shape. I had previously shaped each web to closely follow this shape.

IMG_0648s.jpg

 

However for the piece that bridges the two I used a flat strip and then turned the welding current down so I could lay down a number of beads and grind them level with the flange.

IMG_0647s.jpg

 

So it is now fully welded and a good snug fit. I have not had the courage to drill through the casing for the bolts yet!

IMG_0651s.jpg

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And a few more small jobs:

 

Threaded the ends of some 1/2" EN1A to take the previously made clevises for the radiator tie rod. Followed this with a coat of paint.

IMG_0655s.jpg

 

Blasted, primed and a coat of paint for the "change speed and brake bracket"

IMG_0653s.jpg

 

And the same for the steering box bracket.

IMG_0654s.jpg

 

That's it for this week!

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