Old Bill

You might have it there. Certainly, that little tank of water will either run out in no short order or do very little in terms of cooling unless the water could be contained within the drum. Our drum has no provision for that and is full of oil for the UJ.

I have driven a car with a metal to metal (cast iron on bronze) drum brake and it was quiet, smooth and effective. Railway equipment was always metal to metal until relatively recent years and that only tended to squeal at the lowest speeds just before stopping. The bottom line is that I don't know why they troubled with the system!

Steve

Changing the subject: has the Dennis got a water cooler for the transmission brake? I don't recall ever seeing one on a preserved lorry.

That's a good question, Roy. I have never seen one on a vehicle. However, the GA drawing does show a water tank on the scuttle above the driver's knees and a photo in the manual on an early pattern scuttle, also shows it. (see below).We have found no evidence of one having been fitted to any of the bits and pieces we have obtained, though, and the holes are not shown on the scuttle drawing so it is my belief that they were probably discontinued early on. We have, therefore, decided not to try to fit one. Actually, I haven't been able to see how it worked either as there is no obvious place to put it on the brake drum. Does anyone have any experience of transmission brake coolers?

Steve

I must admit that I don't know although I think that what was removed was thick and nasty through age and use. The manual says such things as 'a good quality engine oil' which is not very illuminating. However, the FWD manual specifies the viscosity and exactly how to measure it although I haven't tried checking myself. I just rang Morriss's and the chap there said 'let me look in the book'! We have always found them extremely helpful and the oil turned up within 48 hours. Great service.

Steve

Good question! I think that the back axle will hold around two gallons and the gearbox about three. According to the manual, the sump has a capacity of five gallons. I hope we don't have to change it very often!

Steve

I don't think dishing it will be too difficult as the spokes are all straight. I just plan to hold the rim of my steel profile in the vice and push each spoke in until it looks about right. I will then clamp the spoke to the edge of the bench and bend the centre part out again until it is parallel with the rim. The spokes are not joined at the centre so the cuts will simply open out. I can then glue the MDF on and dress it to shape as the final pattern.

At least, that is the theory!

Steve

I can vouch for series one being very good indeed with even a cameo appearance from the 60hp Napier car. At one point, they even did the old school photo trick with the tender appearing in several places at once!

The airfield, hanger and Royal Aircraft Factory sets are all outstanding and I hadn't realised quite how good they were at the time. Mind you, I was only twelve when they were first shown!

Steve

Some good thoughts there. Thanks Chaps.

Unfortunately for us, the finger grips are 45° around towards the inside so a fully laser cut/water jet/wire eroded profile just wouldn't work. Well, a posh 3d wire eroder might but there is a lot of cutting to do at some cost as well as the finish machining to produce the 3-d shape.

To CNC mill it from the solid would be a quite acceptable solution but I dread to think what the blank might cost. The wheel is quite dished so a 2" thickness may not be enough. The rim is 1 1/2" diameter in section. If we had our own mill and could write our own programme, then it would be a possibility.

Our aim, always, is to do as much as we can ourselves so the current plan is for me to make a pattern and to cast the whole thing in one piece in aluminium. We don't have the gear to roll the correct steel tube for the rim but I think that the aluminium will be OK, once it is disguised with the black phenolic resin coating. I intend that the pattern will be of MDF glued to a central steel core with the spokes bent to the correct angle. (I can't believe that I had that cut three years ago!). Father has presented me with a rotary table so I can use that to get the finger grips correctly positioned and then cut them out by hand. The real time and care there will be in the marking out but as our time is free then that will be fine. Cost wise, this job could run away with us if we are not careful. Even the steel blank was £45- and I can see the casting being around the £50- mark.

I have just been sent a potential lead so all of this may come to nothing.

Fingers crossed!

Steve

That will undoubtably happen. I have seen it before!

Here is a pic. It is rather poor but we were in a windowless building at twilight time and no torch. It was a case of point the camera and hope! It is 19" OD.

I have had a template for it laser cut in steel to give the pattern some strength. I now need to build up the thickness in MDF to get the shape. The finger marks are going to be the tricky bit but we will manage.

Of course. Thats how we found the carb. "Single 45 year old guy looking for girl with Claudel Hobson carb - GSOH".

Now you're taking the mick! Actually a carb is not a requirement. What I really want is a five spoke 19" steering wheel! :-D

The throttle is a barrel type, just a glorified plug-cock in fact!

Steve

No, the metal won't change over time. Well, not in these conditions anyway. Up until 1900 or so, it was thought that steel 'crystallised' with age and became brittle leading to unexpected failures. This was actually a symptom of what we now know as 'fatigue' where an item will first crack and then fracture due to a repeated loading with a force which is not actually big enough to cause it to yield. Fatigue cracks start at discontinuities such as holes, welds or sharp corners. Temperature can also have an effect. Steel has a 'Glass Transition Temperature' where it becomes brittle as the temperature drops. Depending on the mix, this can be as high as 0°C. Some 'Liberty' ships were lost during the war due to a combination of the steel type, square hatch corners and being used in the very cold North Atlantic. The hulls suffered brittle fracture and just broke up.

Hope this is of interest!

Steve

That's interesting. I might be following general practice, quite by accident! I can certainly believe that coloured leads would have been abandoned quite early due to the spares issue. I have only ever seen them mentioned in the subvention scheme specifications. Tim, is there any other mention in your various books?

Steve

It is amazing what is still out there 90 years later! Thanks for posting, Gus.

Steve

Hi Norman.

You are quite right. Slackening the springs will reduce the pedal force needed. I will certainly back them off before trying to drive it! There is not actually a lot of room on the studs so I may well have to fit half-nuts. At the moment, I have just nipped them all up equally to see what happens as there is no guidance provided in the manual as to how tight they should be. Of course, it might all be a bit easier when there is a seat to push against.

Roy. You will be pleased to hear that I did go looking for the colour coded HT leads. However, I couldn't find leads with different colours but of the same type of wire so we decided to settle for black all round. If you look on our FWD, though, you will see correctly coloured tape around the end of each lead as the leads disappear into a tube and are tricky to trace when fault finding. I think we will do the same again on the Dennis as the leads run through a cardboard tube along the top of the engine and we will have the same problem. Repairing the cardboard tube is my current project. Another new skill required!

Steve

Tony,

 

From the picture of the spring disassembled it seems it was built up without any grease between the faces. Do you have any view on this? I don't think modern springs are greased in this way but I believe it was standard practice in the 'old days'.

 

What material did you use for the exhaust gaskets? Is it an asbestos substitute or the real thing? I have had a go at making copper/asbestos/copper sandwich gaskets using 4 thou copper sheet and with a lot of time and care in folding the copper edges over they can be quite respectable.

 

 

Hi Barry.

Yes, the front springs are new, copied from the remains of an original. Since we had them made, a decent original pair have turned up. Such is the way of this game.

They were not assembled with grease. I have no personal experience of greased springs but one of the fire engine crew at the Royal College of Science told me that they had tried greasing Jezebel's springs and that it had made her much more difficult to drive. Grease isn't mentioned in the manual so we have left them dry.

The exhaust gasket is some modern material supplied as 'exhaust manifold gasket' by a company which provides spares for '50s American cars. It is like a very thick cardboard but is very smooth in texture. We will have a go with it and see how it works out as it is nice to handle and an easy solution for specials. On the FWD, I have made up some copper covered gaskets to see if we can stop the rear one blowing out. I seem to replace that one every year and it is a real pain. Hopefully, the copper will hold it together. We shall see.

Thanks for the tip off for a specialist gasket supplier. It is always good to have a personal recommendation.

Steve :thumbsup:

Very very nice indeed - I presume that it works both as a simple and as compound in the protypical way?

Thanks for the comment. No, it is just a simple expansion two cylinder engine. I did look at installing the centre cylinder (I didn't build the whole engine) but it just isn't on without a total chassis rebuild. It goes well though and I can move fifteen people on dry rails quite happily.

It was building model steam engines that gave us the skills to tackle this lorry!

Steve

A beautiful job Ben. I'm glad we didn't have to make one!

Steve

I would certainly agree with Model T but have insufficient knowledge to date it. That really does need an expert!

Sorry about the recent dearth of postings. I have been concentrating on finishing my loco off, ready for a rally last week. I am planning to draw up the lamp brackets next so Father can make them up. We are also planning a working weekend later in the month to get things moving again.

Too many nice things to do and this earning a living business really gets in the way!

Steve

That's interesting Radek. Please can you tell us a bit about it and a little about the website? What chassis is it? I am sorry that my languge skills are not as good as yours!

Steve

That's interesting Ben. Looks like it must always have been a problem. Dad has just checked our spare original springs (the ones which turned up after we had had a set made!) and they are identical to the ones on the lorry so it is not just our mistake. If we move the axle 1" up the springs, we should get 1/2" clearance which is still pretty tight and nowhere near the 1 5/8" claimed.

I hadn't thought of the effects of a spring breakage. That really would be catastrophic. Lets just hope that it never happens although, no doubt we could fix it if necessary. Fingers are crossed!

Steve

Gosh, that is a bit of an epic trip. You are a lot braver than we are! We are always loaded with tools and rarely venture more than five miles from home! Well done and I look forward to seeing it in the metal.

Steve

That's right. The front springs are brand new using rotten originals as patterns. We have fitted the axle in the centre of the springs which seemed logical at the time. However, I am beginning to come to the conclusion that the axle needs to be moved 3/4" forward to give us a clearance. This will tip the king pins back slightly increasing the castoring effect and mess up a lot of paintwork! I must look into the job a bit further before we attempt to do something about it. I will also ask Dad to take some pics of the problem as, surprisingly, we don't have any yet.

There's always something.

Steve

Thanks Gordon. I don't think there will be a problem as long as the alignment is reasonable. Just to add to your list of variation, the subframe came out of a different chassis altogether and the engine came from a fire pump and has never been in a lorry at all! The engine was mounted on some thin shims in the pump assembly and we have incorporated one of those into the lorry. Father will cut out four pieces of 1/4" plate and we will just lift the lot straight up. Hopefully, this won't mess up my pump-radiator hose connection.

There is a surprisingly large fiddling and messing element in this exercise, to get it just right. I now have a new concern in that the front axle is just underneath the joint flange between the sump and the crank case. Any spring deflection of 3" will cause the axle to smack it and probably break the castings. Probably OK in normal driving but if I hit an unseen speed bump we may well be in trouble. Another puzzle to ponder.

Steve

Thanks Ray. I have just had a look but it is a bit of a poser. It is slightly out of my era but I shall look forward to reading the comments from those more knowledgable than I !

Steve

Hi Gordon!

Yes, I agree that some extra weight would help the prop shaft alignment but it is not very far out so I am not really concerned. The main alignment problem is between the engine and the gearbox. Both the crank and the main shaft are on the lorry centreline and parallel to the ground but the crankshaft is 1/4" lower. We had to ease the coupling slightly to allow for the amount of articulation needed to connect it up so I think it would be a good idea to try to reduce this with some packing. We could lower the gearbox, of course, but that would give problems for the change mechanism. The puzzle, really, is why they are out of line in the first place. Both engine and gearbox are secured through the original holes!

I have just had an exciting telephone call. I think we might have found the correct carburettor! Should be able to pick it up in two weeks. It's all getting exciting now!

Steve