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BenHawkins

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BenHawkins last won the day on January 1 2019

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    Birmingham
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    Engineer

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  1. Some companies will apply the rubber to a loose band, others will insist that they are mounted. Certainly putting the wooden wheel through the autoclave for the vulcanisation process will destroy it. I have led Steven down the wrong track with the wheels for ED-810, that has the lighter weight axle (used on 30cwt lorries). He appears to have the rear axle used on two and three ton lorries with larger hubs. It should all become clear as he dismantles what remains of the wheels.
  2. Back in 2005 a friend of mine found a late 1920s Dennis chassis in Kent (I was in no position to take on a project at that point). It did not find a home but was broken up and virtually all the parts distributed across the country to help restoration projects. Unusually the chassis still had the petrol tank mounted but after all these years it turns out it did not fit the intended project so was offered to me. The body layout drawings in the 1908 catalogue give the dimensions as 15"x9-1/2"x3'6" - exactly the size of this one. It has the Snercold patent filler described in the catalogues too. Snercold was the trademark for the Safety Non-Explosive Reservoir Company
  3. More photos for comparison. A wide single front on a Dennis hub. It is possible a wider rim and tyre were fitted at some point. An "original" front. I just cleaned it up and painted it. New 100 for 720 tyre. It was necessary to press the tyre onto the rim with canvas between to get sufficient tonnage. A professionally rebuilt front. All new timber with original hub and steel rim. Some of the timber that was replaced. Note the felloes are approximately the width of the tyre fitted. The heat shrunk rim is usually wider. In addition to protecting the wood from kerb damage this is also essential for pressing on the tyres - you do not want to be applying the load to the timber. An "original" or at least not rebuilt rear. This is of much heavier construction than typically seen on a 3 ton lorry. Not the additional bracing band for the brake drum and how much wider the spokes are than the felloes. Heat shrunk rim protrudes on both sides of the wheel. Rebuilt wheel, this is a copy of what was removed but a different design to the other side. Note the spokes are much narrower. The "as found" spokes and felloes. On this vehicle twin 120 for 720 tyres were specified. Note the felloes are approximately 230mm wide. The new ones ended up slightly wider.
  4. After several checks of the dimensions I drilled the radiator side tank castings for the mounting holes and then tried fitting it to the chassis. There is still some adjustment to be done and some more checks before drilling the tube plates.
  5. I am not sure how much use the dimensions from LE9588 will help. Although a similar model yours is actually a heavier weight version. LE9588 has a similar back axle but runs on single rear tyres; the rear springs only have shackles at the rear; yours have shackles front and rear and the axle alignment is constrained by locomotive style horn brackets (not present on LE9588). I believe according to the build sheets they were "860x90" (front and rear) tyres on the LFB pumps for 1911. I am pretty certain these are Avon tyre sizes, so the 860 refers to outside diameter rather than band size. I suspect the band size is 720 but can't be certain. Although later, a better match for your wheels is probably ED-810 (owned by a member of this forum). The engine picture you posted is an earlier version (probably 1907/08) but pretty similar. By 1911 the serpentine water connections had been dispensed with and the connections were made between the cylinders at the centre line. I hope the works production order for your chassis survives as it should answer most of the questions and I will finally be able to give you some definitive answers. The archive is once again welcoming visitors but I imagine there are still restrictions in place and as you know this made our last visit less productive than usual. Five hours of driving for a couple of documents (ordered in advance) means we have to continue with other projects at the moment.
  6. Thanks Barry, I was keen to avoid the UV exposure and developing stage of the process so gave the toner transfer a go. There is a light box I can borrow but it is too small for the tread plates. I might give the dry film a go for the ID plate on the 1908 Dennis; that one is a slightly different design and it is always fun to try another method.
  7. I would like to thank everyone for their support of this project. I know it does not completely fit the military theme of the forum but hope that it has been of interest and useful to other people attempting similar restorations. To answer the question about etching, the toner protects those areas from the ferric chloride. I obviously didn't get it perfectly adhered as there was some shallow etching behind the toner (simulated patina?) Following the etching I cut the identity plate out and painted it black. Fine silicon carbide paper stuck to the back of my steel rule was used to polish it back to reveal the raised areas before stamping the numbers. Two of the fields are left blank; I will stamp them if I ever find out the correct numbers (when new). I believe both numbers were a little bit below 800 from surviving Works Production Orders. The number is on the axle somewhere but obviously I don't have the original gearbox. Six weeks ago I did the artwork for the tread plate and sent it off for manufacture. I am lucky because the original drawing survives, it could have been made from that but I didn't want to pay someone else to have the fun. There are plenty of etching services available to do this sort of thing but I wanted some for both of my Dennis vehicles with a deep etch and someone who could deal with a CAD format (such as DXF) rather than a Corel EPS. Originally I tried some steam model people but ended up using a machine nameplate company in Scotland. They worked out at £27 each (delivered) and their production line laser cuts the profile and does the blacking and flatting back. All that was left to do was countersink the holes and screw it down! So that is two ways to get the job done. The tread plate is bigger than the transfer paper so would have been more difficult for me to do, also I wanted a few of them so was able to split the cost of the mask they have to produce. I am running out of things to make for this vehicle; it's been fun and hopefully we can get it out a bit more in the near future - the speedometer calibration needs testing!
  8. I have been working through the "finishing touches". Originally there was a small brass plate fastened above the bonnet carrying the vehicle details. These survive on other preserved Dennis vehicles and I had taken measurements and rubbings in the past. Using Computer Aided Design I was able to generate the artwork and print it onto some "press-n-peel" film. This is basically a plastic film with an emulsion on one side. It has to be printed on a laser printer; apparently some brands of toner work better than others. The artwork has to be a mirror image of what you want to retain when etching and you have to make sure you print onto the matt side with the emulsion (the CP&Co asset tags are for the other projects). The brass plate needs to be free of all contaminants; this was a piece of polished brass that had been protected with a plastic film so there was no need to clean it back. With the brass on a wooden board and using the "garage projects" iron the brass was warmed up (being protected with a sheet of paper). The blue film was then placed on the brass, toner side down with the sheet of paper on top and given a further ironing. The instructions warned not to press too hard or the edges might smudge. The instructions then said quench in water and peel off the film. Not quite the result I wanted. Second attempt, ironing for longer with more pressure. Some of the artwork was rectified with a marker pen and I inked in the back so it would not be etched. It was then immersed in ferric chloride for a couple of hours. Finally it was washed under running water.
  9. Thanks Doc, CP&Co bought several batches from Dennis and I think I now have photos of every batch but the one mine was in (end of 1908). They did not have Dennis bodies fitted so there were no factory photos taken, originally I thought the motor vans were used in central London, but the picture of the Addlestone district probably suggests that they were used where properties were further apart.
  10. I decided to stitch a leather belt for the speedometer drive. This started with a hole pattern and scribing lines as described in a lathe manual. Then stitching in-situ with waxed twine. And finally putting it in place. To make the speedo cable I turned up some brass ends and soldered them on to some 1/2" brass flexible conduit I purchased at an autojumble. Steel ends were turned up for the inner and crimped on by placing them in a vee block and punching it down with a centre punch. That is another thing to test when lockdown ends. I have a speedometer app on my phone to check I got the maths right.
  11. I found this picture of the odometer used on the early Thornycroft BT. It appears to have a plate that swings over the number to protect them.
  12. We have been digging trenches and mixing concrete this week so I have been looking through old magazines when I need a rest. This is a 1906 notice from Carter Paterson advertising their investment in speedy motors. And some Dennis vans in Addlestone, these ones were built in 1911. They still have the horizontal tube radiator but mounted on trunnions rather than shackles.
  13. Dennis must still be busy as they cannot supply me a replacement gearbox. Their standard answer is they sold the last one yesterday!
  14. Thanks Andy, I will dig out the original factory drawing and annotate it for the new diameter, or is a new fangled step file better?
  15. I have finished machining the speedo drive parts and fitted them to the lorry. The next jobs are making the flat drive belt and flexible drive shaft. The tensioning spring is a bit too long and weak but it should be easy to sort a replacement.
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