Asciidv

Steve, is your engine running hotter because of the modern petrol? It would be interesting to have an exhaust gas temperature probe in place and try different petrols.

Even the 'return' on the bottom tank seems to have come out well. The work Steve produces is just amazing. We are very fortunate to be able to look at these pages and see the exquisite skill and craftmanship coming out from a shed in a back garden.

6 hours ago, andypugh said:

A VFD might be more convenient, and quieter. 

Andy, it is probably a 15 horse motor, so a VFD at that rating would be very expensive. Anyway, I believe that Australia is a big place, so you wouldn’t hear the noise of a generator...

Ben, when I have had cast wheels rubbered the tyre bands were not removed but were wound in situ on the wheel and then the whole wheel put into the autoclave. When you had your tyre bands re-rubbered could they accept the tyre band directly or did it have to be mounted on a donor cast wheel? I am under the impression that the conditions for vulcanisation would always be too severe for a wooden wheel.

Andy the profile of the spokes is actually quite complex.

More pictures showing wheel construction. The spokes are not quite parallel sided.

Andy, I am thinking of going to a traditional wheelwright for final assembly but as he makes all his spokes by hand it seems an unnecessary waste of time and money. The same goes for the felloes.

Rather than mucking up my VMC with wood dust I am now tending towards commercial CNC routing job shops who have hard wood experience. I need 24 spokes and if Steven joins in that would be 48 spokes.

Maybe rough the spokes on a bandsaw and just use this for finishing. I wouldn’t like to snap it as this price!

Steven, the spokes are parallel at 4 inches wide with the wheel being just over 6 inches wide. I am just preparing some fully dimensioned drawings for you. It did cross. my mind whether CNC routers can run with 4” long cutting tools as one would make short work of the spokes?

One of the great mysteries of these components is that I am convinced that the brake drum was drilled for the coach bolts using the hub as the template and then kept as a pair. The drilling of the hub (even allowing for the difficulty in picking up the true centre of the holes due to the fretting) does not seem up to the usual Dennis precision. When I made an aluminium plate template from one side hub there was no way in which it was going align with the  holes in the opposite side hub.

More Wheel pictures can be found on this ED810 Flikr page:

 https://www.flickr.com/gp/asciidv/R9638M

This is one of the actual wheels. At some time the original full width hoop has been removed and two new bands were fitted at either edge of the wheel these bands were then screwed into the wooden wheel. The wheel with the bands was then inserted into the tyre. As it was slack and not a press fit the bands were then edge welded to the hoop of the tyre. To make extra sure that everything was going to hold together coach bolts were then put through the felloes into the actual tyre  band and the nuts countersunk into the rubber! All of this was done at least 50 years ago.

So the plan being is to have new wheels made with the correct size hoop for a tight press fit into the tyre hoop.

These are pictures of my hubs. The wooden wheel is clamped between the hub which dogs into the drive shaft and the brake drum. On my machine both the holes in the hub and the brake drum had fretted oval so they were drilled out and oversize coach bolts made and fitted

For those following this thread and wonder what it will end up looking like, here is a link to my own similar Dennis;

1914 Dennis 'N' Type

You may wonder why there is a preponderance to wheel pictures. This was because Steven is interested in having new wooden wheels made to make his machine authentic.

Ben, I normally use the dry film resist material rather than relying on toner transfer. It certainly is quite tough and allows for long etching times if you need deep etches. I also have had good success with the brass chemical blacking solutions as an alternative to black paint. It will never flake off!

Andy, do you have any facility to grind the balls after they have been turned? I noticed that your lathe has variable speed but the sound from it did not seem to be synchronised with ball diameter only to the start and end of each cutting cycle?

Does the Puma live to fight another day? 

Tube Fins Limited here in the U.K. seem to do everything that is needed including solder tank dipping,   

http://www.tubefins.co.uk/WireWound.aspx

and they are almost just round the corner from Ben and Steve!

48 minutes ago, andypugh said:

Yes, definitely the best way. But even a trough built specifically for doing one tube at a time (40 x 40 x 700mm)  would need about 10kg of solder and some way to heat it. And that would be £250 of solder just to fill the trough, before any tubes are soldered. 

 

(And I think that is why it is hard to find anywhere that can dip a complete radiator, that's a _lot_ of solder to have tied up, and a lot of energy to melt it) 

Andy, when through hole PCB soldering was superseded by surface mount technology I couldn’t bare to get rid of our Hollis wave flow soldering machine. It has at least a 50kg solder tank and 3 phase heating. There is a fluxing tank at one end a long conveyor with titanium fingers which passes the boards over pre-heaters and then the wave solder tank at the opposite end. By adjusting the wave height it would probably solder gilled tubes in a longitudinal manner easily. 
 

I like this punch. Simple to make and producing 40 in a single stamp. Although after they have been punched they need cutting out, a laser profiler would make short work of the task. Only 350 swings of the fly press against 14,000......I wonder which the glamorous assistant would choose?

Andy, Ben, if you want sharper corners I can wire EDM the bits. It might be an advantage to wire EDM everything from tool steel so that hardening is not necessary, Barry.

( Ben, does what you have drawn give a completely turned over tip to the petal or just a little flange at the end of the petal ? 

O.K. Andy, let us see you turn the tips over!

Andy, I was thinking on similar lines, but cutting the petal shape first and then forming the petals and cutting the outer square. The petal cutting die has to retract to permit the forming and like you I wondered about a heavy duty spring although in reality I think it will have to be a latch.

Andy, I think the simple pyramid would just tear the metal as it forced it’s way through without any cutting action. Should we have a Christmas competition to design the best punch as there will be nothing worth watching on TV?

Please make them! I am sure that we would all like to see how you go about it. You could imagine if you blanked them first and formed them in a second operation then the tooling would not be that difficult to produce. To do it all in a single hit needs a bit more thought. I wonder if the turned over tips of the segments are really necessary? 

Ben, Looks very good! What length of end mill do you need to get to the bottom of that face? Did you finish off the screw cut bolts with a die? The thread length looks very uniform or can your glamorous assistant throw your lathe into reverse with super fast reactions just at the right length?