BenHawkins

A slot was needed in the bulkhead so I drilled a row of pilot holes.

Then drilled them out.

Finishing off with a file.

I had to make a few extra clevis pins and shoulder screws.

The magneto is on the opposite side to the steering column so a transverse shaft is needed. I roughed some blocks to size using the shaper.

Then scribed out for drilling the holes.

On ‎5‎/‎9‎/‎2018 at 8:30 AM, Redherring said:

The Dennis is very bright 'red' in colour. Is this shade original?  Are you likely to get booked for speeding by every passing patrol car?  Robert

It is a close match to the paint that was left under various fittings on the chassis, but that may have just been an undercoat. Later vehicles owned by Ernest Shentall were closer to maroon.

I have chiselled out for the hinges on the tool compartment.

The front has now been trimmed back and the whole lot given a coat of paint.

To run the engine I need to be able to connect up the magneto and carburettor to the controls. I sorted out some of the pieces I have salvaged over the years.

I put a gallon of water in the radiator and it started to leak out the lower flange and past one of the bolts. I let it dry out, pushed a little sealant in the gap and around the screw and tightened it all down a little more.

It was a nice warm day so it was easy to tighten the clamps down to stop a couple of minor leaks at the rubber hoses. That just leaves two left; one from a welded boss and the pump gland.

The welded boss was the drain plug when the engine was in a generator set; the manifold was up the other way and the radiator was mounted over the flywheel. I think it will take a couple of days to fill the miniature wheelie bin.

The water pump is 1-1/4" but the radiator plumbing is 1-1/8" so I cut some brass tube to length in order to make the adaptors.

I bent some copper pipe and soldered some fittings together to link the radiator bottom connection to the pump inlet.

I then tried putting it all together.

There is not much clearance between the fan and the pipe but it should be enough.

I cut some 3/4" Sapele to length for the top of the seat.

And six short planks for the front of the seat box.

The long planks were dowelled together and braced on the underside.

An access hatch was cut for the tool compartment. Access to the petrol filler is via a hole that was cut with a hole saw and then rounded off with the router.

I then fitted the straight portion of the sides.

And working out from the centre at the front I fitted the rest of the screws whilst pushing the zinc to follow the shape. There is a little undulation in the centre front but it looks good from ground level.

I had the roof beading laser cut so it started out with the correct radius. I used a file to break the edges and countersunk the screw holes.

The back of the cab was the best place to start as the zinc was happy to follow the curve.

I could not shrink the zinc sheet so cut small notches between the screws to help the zinc follow the shape.

I have welded an extra 1.5" into the fan bracket flattened it off so it is difficult to see the mistake.

The floor panel has been painted.

I have welded up the bell crank bracket for the magneto linkage and given it a coat of primer.

I attacked the edges of the crank with an angle grinder.

Before cleaning up with a file.

I still need to link up the magneto and carburettor to the controls. One of the things needed is a bell crank for the magneto as the timing adjustment needs an up-down motion but the control rod needs to be fore-aft. I decided to copy this one from my 1908 Dennis.

The bell-crank was laser cut from 10mm steel; the 3/8" diameter holes can be cut by the laser (as a rule of thumb the minimum hole diameter the laser can cut is equal to the material thickness). However, I wanted the one hole to be 3/16BSF and that is certainly too small for the laser to manage so I marked out and used a centre punch ready for drilling.

Then it was simply a case of drilling and tapping.

I then took a chisel to the floor boards to finish cutting the recess.

Followed by a trial fitting of the flush ring.

The braces were trimmed back using a saw and giving a few degrees of taper.

And then back to painting.

4 minutes ago, Richard Farrant said:

Hi Ben,

Can you make spacers up to fit between the mountings at bottom?

regards, Richard

Hi Richard,

They need to be around 1.5" high; it would solve the fan issue but then makes the plumbing for the pump a problem. It should be possible to weld an additional piece of steel in without it looking too bad.

Thanks,

Ben

I decided to go back to messing with the floor boards. I trimmed the three central floor boards, doweled and glued them together and screwed two braces across the underside.

This floor panel needs to be easily removable in order to gain access to the transmission for servicing. To make this possible there always seems to be a flush ring; I had a 2" version on the shelf and the glamorous assistant suggested I could use a hole saw to cut the recess.

Most of the centre was removed with a flat spade bit of 1-1/4 diameter.

I welded all the pieces of steel together to make the fan bracket. I left the eye at the top a couple of thou under size so I could ream it out until it is a snug fit for the fan.

That bit seemed to work.

Then I tried it in position. The fan only clears the chassis rail at the highest point for the eccentric belt adjustment. I am not sure how I got the dimensions wrong but it looks like I need to splice some more steel in. 

I unbolted the number plates and took them to work. My employers kindly let me use their printer.

Then refitted them.

I have collected my latest batch of laser cutting and welded some of it together to make the pump bracket. The glamorous assistant helped my line this up in front of the engine along with a tacked together fan bracket to check it all looked plausible.

The infill pieces need bending into shape.

I have bored some 2-1/4" diameter EN3 out to 1-1/2" to match the fan; when it is finished it will be welded to the top of the bracket.

On ‎16‎/‎04‎/‎2018 at 1:12 PM, Asciidv said:

Ben, are you going to use a sheet metal shrinker to take the ripples out of the turned over lip on the roof or do you have some other plan? I have been looking at one of these for years and could never decide whether they are any good or not. Does anyone here have any experiences of using one of these?

Before I started shaping the zinc I did expect it to be similar to lead, but it is actually much more difficult to form. It is work hardened so it either needs shrinking; cutting or just hiding under the beading. I am not sure which yet.

This week has been filled with small jobs. The magneto coupling is fitted and the wires run to the switch (now fastened to the bulkhead with 6BA screws. I get sparks with the switch in the ON position and no sparks with it in the OFF position so I consider that a success.

The pieces of timber to fill in either side of the cab have been cut.

And that allowed me to cut the central boards to length.

All those floor boards have now been primed.

On ‎16‎/‎04‎/‎2018 at 8:12 AM, Asciidv said:

When I have made up oil pipes for pressure gauges I have always just soft soldered the nipples on and not silver solder like what Ben has just used. On this era of vehicle ( pre-WW1 ) was there a preferred method?

Looking forward to hear the engine start. Engine starts seem to be coming thick and fast now!

 

The original oil pipe that came with the engine was silver soldered but the gauge was mounted on the front cylinder block (no bulkhead on the generating set). Soft solder would probably have been fine but more practice at silver soldering does not do any harm!

On ‎04‎/‎04‎/‎2018 at 10:30 PM, Old Bill said:

Many thanks for all of your thoughts. I am pretty sure that I don't need the hot air inlet as modern fuels are so much more volatile. However, I will keep that one up my sleeve for the time being. I have been doing other things today whilst I mull it over but I have investigated the timing and this is what I have found. Taking 'valve opening' or 'closing' as the point at which the tappets contact or part then, at the moment:

Inlet opens at TDC

Inlet closes 34° after BDC

Exhaust opens 32° before BDC

Exhaust closes 5° after TDC

Steve    

I know I am a bit late with this but I found this timing diagram in a 1920 Thornycroft Q Type instruction book (and believe it had the same engine).

I found I did not have any suitable screws for fitting the switch so had to move on to something else. It looked like starting the engine was getting closer so some control linkages will be required. The hand levers (for ignition timing and throttle) needed some leather washers to generate some friction so I cut a couple from some scraps I had on the shelf. I looked through the stocks of bell cranks and brackets, decided I was lacking sufficient parts to complete the task and sketched up some blanks for laser cutting.

The zinc roof is starting to look like the correct shape; I expected it to be a little softer but it should be possible to get it to follow the profile. I don't know how Dennis managed it without ratchet straps and speed clamps.

The doors have been flatted back, rehung and given another coat of paint.

And finally the v5 has come through from Swansea so I now have a number to paint on the plates.

I have fitted the pressure gauge to the bulkhead and bent some copper pipe to connect it to the engine. The next step was to fit the nipples I had made previously. It was a chance to give the Tenacity no 5 flux a go.

That was successful so we cranked it over for a couple of minutes on the handle until we had oil pressure.

I then decided to fit the ignition switch, this needed a 2" hole and three 1/8" holes for the securing screws. This is fairly easy to mark out as you can set some dividers to half the PCD and mark out the corners of a hexagon and only use the three you need. The large hole was cut with a hole saw as I happened to have one the right size left over from building the house.

The camera does make the steel look brighter than in real life but we certainly overheated it. We used two burners to heat it, the larger one is meant to be 86kW and the smaller one about 40kW; it suggests we should be able to heat the real job up to temperature, especially as I have just purchased a second 86kW burner from ebay (other auction sites are available).

Spelter brazing looks interesting; can I buy the spelter pre-made?

Thanks for the suggestions!

31 minutes ago, smiffy said:

 What flux do you use ? I use Tenacity no 5  which seems to stand the higher temperatures and I would use oxy acetylene  as the heat source . Is it possible to  tig weld the propshaft .   Mike

Thanks Mike, I used easyflo so only good for 800C and have ordered some Tenacity no 5 to get the extra 100C.

I could fit a jubilee clip around the burner nozzle to reduce the air and give a reducing (and cooler) flame; I am working in a well ventilated area so the risk of Carbon Monoxide poisoning will be minimal.

The joints could be welded into the prop shaft tube but I am trying to keep to the original drawings.

It has been a busy week as we managed to purchase some more land and had to put up a fence! I don't think this will allow us any more projects but should ease constraints on the current ones.

I still managed to make a bit more progress on the bodywork (and the usual painting). I cut more triangles to support the floor and lined them up to give a 1" recess for the boards.

Then belt sanded the end flush.

After those were painted and fitted it was possible to measure for the floor boards.

I cut the first board to length and planed the edge to match that angle of the floor.

The next board required holes and slots to clear the pedals and steering column. It ends up a bit flimsy in this area so I will probably put some steel on the back.

I did not manage to complete the third board; I can save that one for another day as it has more notches and the top edge needs to be planed as well!

Having stopped at a petrol station on two occasions; there are two gallons of petrol in the tank and so far none on the floor.