Engineering Modeller

Folks, many thanks for the compliments. I just wanted to say that how valuable these forums are, when I started this I had no intention of trying to do a full scratch build but when you look around and see the work that is accomplished by many of the modelers it is really inspiring. I have learnt a tremendous amount looking at other builds so it is thanks to all who contribute to the forum. Graham

Thanks guys I appreciate all the comments! The lathe is a Colchester Harrison that I bought a good few years ago. The four jaw chuck is the Pratt Burnerd and is really nice, the 3 jaw is a TOS and is also pretty good. The question regarding what is behind, if you are referring to the black stuff its actually a piece of plastic damp proof course. It catches most of the swarf and is then easy to clean with a vacuum cleaner. I first tried this when I was machining some cast iron locomotive wheels and it worked great, cast iron swarf is a real bugger and when mixed with oil forms an abrasive that you want to keep off the lathe. Today I finished off the clamps for the other three wheels and fitted the tyres. This is how far I have got, still loads to do but it's taking shape.

I found some brass that is a suitable size to make the beads! One bit had a hole in it but by cutting a groove in the face I managed to make the inside dia of the bead. Parting off a bead This is the form tool I used for shaping the profile of the bead. Next job was to make the bead clamps. For this I used some 6mmx0.58mm brass strip and I made a former from guage plate. The gauge plate was hardend by heating to cherry red and plunging into water. The former. Ready to file one end Then the other end To bend the clamp I first annealed the brass by heating to dull red and plunging into water this results in a nice soft brass that can be bent. I used the engineering clamp to do the final bend to the shape of the bead. Fitted with the Pocher rubber. Just 3 more to do.

Hi Sam The model is based on the Pocher kit at 1/8 scale. I had originally just thought I would try and make just the chassis out of brass but the more I have done the more I think I shall do a scratch build of the whole thing. I am using the Pocher brass parts where possible and the chains are Pocher. They are a bit fiddly to make but not too bad. Graham

Thanks guys, I appreciate the comments. This is probably going to be my last post for a short while as I have a couple of other projects that I need to progress. In the mean time I have uploaded all the photos to a website that I run. It includes a lot of images that I have collected from the Net of real cars which maybe useful to others building the Fiat. You can see them here Graham

A few more shots of the wheels. Starting to shape the spokes. Rear and Front Wheel. The nuts on the rear came with the Pocher kit, the others are 12BA I now just have to find some suitable material/tube from which to make the beads.

Hi H You are right I did quench in water, but I wanted to see how hard they were before I annealed the springs. The answer was incredibly hard/brittle and in fact the one I tried snapped as I tried to bend it. Once annealed they were ok ie they do now spring but still too stiff for a model car. From what I have read you can quench in oil or water, water giving a harder result. The trick then is the proper annealing to bring it to the desired result. Next time I shall try oil. Thanks Graham

H Yes thats my thoughts only problem is the outside dia is 82mm and inside 73.2mm. So far I have not found any tube that fits the bill but I could do it from a solid bar and make a lot of swarf! Graham

Thanks Harvey, I think you are right, I need to get hold of some thick wall tubing and then turn it on the lathe. Graham

Folks, I have found some time so I am back on the Fiat tackling the wheels. But before that let me say thanks for the kind comments and Harvey was definately correct the springs are much too stiff but they look the part. It would be nice to have them looking correct and exhibit some suspension but I have no idea how to achieve that. For the wheels I decided yo use some American Oak that was left over from a cabinet I made. I had originally intended to get the spokes laser cut but then thought I would give it a try on a powered Fret saw, it turned out to be fairly straightforward and by using a small belt sander I was able to bring them to the finished size fairly easily. For the rim I decided to use 6 felloes which gave an angle of 30 deg. I glued the felloes using Wicks no nonsense cyno and the rapid activator. It seems to work very well and gives a strong bond. The circular one is just roughed out ready for putting on the lathe and turning to finished dia, the extra one is just in case! The next photo shows the spokes in the wheel building jig. This was just a piece of scrap ply with a hole of the correct dia. A piece of baking parchment underneath the spokes ensures the spokes don't stick to the jig. I used Gorilla glue for the spokes. The wheel is then mounted onto a threaded shaft the same dia as the hub and the external dia turned. The Front Wheel still needs a bit more sanding but its getting there. I will post photos of the others shortly. There is still one major thing to do on each wheel and that is to add a bead plus the securing bolts. These are a couple of photos of the real thing and show the bead, at the moment I am not sure how to make them so if anyone has any ideas I would be most grateful.

Thanks for the kind comment guys. I must admit I have not done much on the Fiat recently as I have been busy with a few other projects but I will continue in a few months time.

Brake and Gear Change Lever The image is of the real car that I found on the Web. The Gate Shaping the handle Winding the spring for the mechanism, I used a violin string. This was probably the most difficult part of the build so far, the components were pretty small and the soldering tricky. I wont boor you with how many times I had to re-do the soldering but it was a few!

Well I finally obtained some steel for the springs from Reeves 2000 here in the UK. The steel was in a soft state when delivered and you have to heat treat it in order to produce the spring state. It was surprisingly easy to cut and drill , just like mild steel. Bent and ready for heat treatment. Using gas propane torch I heated to cherry read and plunged into water. This is the result before descaling and a test of how how hard the springs are! As you can see they are extremely hard, the broken leaf was the result of me just attempting a gentle bend and I broke another one when trying removing the scale. So before I did anything else I tempered the leafs in a domestic oven at 250 deg C for an hour. Then polished and removed the scale before finally heating again and bluing. Temporarily mounted. at least they now support the weight of the car! Having said that they are actually far too stiff to act as springs and I am not sure how that could be resolved. Maybe I should have just made a single leaf from spring steel and the rest out of plastic.

Thanks for the replies regarding the springs, the German Knupfer site looks fantastic but I managed to fine some spring steel from Reeves2000 which I have ordered as it was somewhat cheaper.

Hi, there is nothing special about the saw I think it is a small Eclipse piercing saw with some fairly fine blades. Where possible I try and avoid using the piercing saw as I have a habit of breaking the blades and use a junior hacksaw with some eclipse blades if space permits. As for lubricant I don't use anything on the brass but would use a drop of oil on steel, having said this I am no expert and others might be able to advise if a lubricant would be better.

Hi folks, thanks for the kind comments much appreciated. One of the next jobs I have is to make the leaf springs, the plastic ones that come with the Pocher kit are too weak to support the weight of the brass body. I have been looking for some suitable material but so far have come up with a blank, if anyone has any suggestions they would be gratefully received.

Brake and Gear Change Lever The image is of the real car that I found on the Web. The Gate Shaping the handle Winding the spring for the mechanism, I used a violin string. This was probably the most difficult part of the build so far, the components were pretty small and the soldering tricky. I wont boor you with how many times I had to re-do the soldering but it was a few!

Pump Machining & Fabrication The difficulty with the pump was threading the top cap as it is so small and only has about 4 threads. I therefore decided to make it in two parts, the threaded bit, the top and soldered the two together, I cant claim that it actually works as there is no seal inside the tube and no valve at the bottom. But I think it looks pretty realistic.

The Pocher kit comes with the gears for the steering box so I have used these but fabricated the casing from brass. The only tricky bit was soldering the ribs, I used soft solder and held them in place with engineering clamps and some steel blocks. Preparing for soldering. I had to machine the case to provide additional clearance for the worm wheel.

I machined the hubs on the lathe and then transferred to a rotary table for drilling the holes. The four hubs were drilled at the same time.

Next was an attempt at the radiator. Start of the soldering Trial mount (still with wooden former) Mesh for grill Forming the mesh for the grill I used some thin brass shim to make the folds for the radiator The Pocher kit came with a nice brass Fiat badge. I tinned the back with some soft solder and then clamped to the radiator with the engineering clamps acting as heat sinks to stop the whole thing falling apart. Luckily it worked

Hi folks Its been a while but here are some more shots of the build. There is still a long way to go. The bonnet showing hinges and how it should look. Machining the hinge Soldering the louves.

Folks, many thanks for the kind comments I appreciate them. The solder I use is standard plumbers together with electrical for the smaller pieces. There were a couple of exceptions to this on the front stub axle where I used silver solder first and then plumbers solder on the next component. As silver solder has a much higher melting point I could solder on the next part without fear of melting the previous joint. I have used a Sievert torch and propane for all the soldering so far, its a fairly small burner a 393802 but a smaller burner would probably be better still. I did try an electrical soldering iron but it was just not powerful enough to heat the components. The brass thickness for the chassis, seat mounting and cab is 1.6mm. The frame on the cab/dash 2.6mm. These thicknesses seem about right and look ok for the scale of the model. When bending the brass its important to anneal it first. I did this by heating it to cherry red then cooling by plunging into water. At first I had mixed results until I remembered that its not just getting it to the correct temperature you also have to hold it at that temperature for some time (a minute or so) to allow the metal to change its structure. Once I did this it becomes surprisingly easy to bend with just your fingers. If there are a few bends to make in the component you may have to anneal more than once as the material will work harden as its bent. .

Wow, this is my first look at your posts and all I can say is fantastic. Really inspirational! Graham

Nigel many thanks for the kind comment. Just one more shot with a few parts placed on to the chassis.