A few pictures of my TE

kevingambrell · 22-01-2007

Hi

A few pictures of the almost complete traction engine. Its 1 inch to the foot
coal fired. The paint is all brushed enamel and the lines are put on using a bow pen.

http://s138.photobucket.com/albums/q268/kevingambrell/

I should be starting the boiler on the next engine in a week or two
having a go at a Fowler Superba in 2inch should be interesting.

kevin

**Bunkerbarge** · 22-01-2007

Kevin that is absolutely superb and a perfect example of the engineers skills being used in the scale model world. Many thanks for sharing the pictures.

It is interesting that you brush paint the models. Long after the introduction of spray gear for motor car manufacture Rolls Royce continued to brush paint thier car bodies as they believed they produced a better finish.

Also the use of a bow pen is something of a dying art. When I was at school and doing technical drawing we were just getting to grips with the new fangled Rotring pens. Any technical drawing set purchased at that time included a bow pen and certainly a bow pen attachment for the compass. They are definately not the easiest tool to use.

I am sure any construction pictures would be appreciated if you have any. I would love to see the way you have made some of the engine and boiler internals.

kevingambrell · 22-01-2007

Hi Richard.
thank you.
I must admit I just dont like spray, it never seems to give good coverage and a lot of times seems to send a lot of paint to the bench. Brushing is a little longer winded but if you rub between coats it gives a deeper richer look to the surface. Ah the bow pen! how many drawings are floating around with blots from those things! i still have all my drawing tools including about a dozen bows. For putting coach lines on its the tool of choice. It lets the line form with out a sharp raised edge unlike masked lines

I added a few pictures from the build to the photo bucket account. ill find a few more as the week goes on.

the T rings are not as most aluminum castings, on this one I grabbed two MS billets and treppaned the front T's from the inside of the rear T's. It took about three hours to trappan both billets, and about four weeks to cut the spokes and strakes. Each wheel has about 100 1/16th iron and copper rivetts.

The cylinder block is GM with a CI linner. The steam way was enlarged from the drawing to give a better flow and the safety valves were improved to give a 30% margin of steam flow.

The next one is a fowler Superba times two. and ill try to document the build as I go. My plan is to have it them steam by about 2011 and finnished about a year after that. the boiler's will be steel on these one's partly due to the winch under the boiler and partly due to the working pressure.
I also plan to build a plough to go with the two engines.
To be honest making two engines the same is not a lot more work as all the jigs and fixtures are ready made from the firts part.

kevin

**Bunkerbarge** · 22-01-2007

Just so that we are on the same page, Trepanning to me is using a parting tool to cut into the face of the work by running it in with either the cross slide or the compound. Usually for the high forces generated I would lock the carriage and use the compound and just releive the outside edge of the parting tool to clear the radius.

Is this the same procedure as you used?

kevingambrell · 22-01-2007

Hi
Well kind of, the compound slide really should only be used if your cutting a short tapper on a bar. This is due to the uncertainty in re setting the compound after a tapper cut. In treppaning the forces can also be very high and the lead screw on the compound is not as befy as the rack on the saddle.

On small trerppaning jobs the compound would be fine. i once had the job of treppaning two hundred small parts from large diameter brass bar. the idea being it would save the cost of more bar stock. This was done using the compound with no problems.

The T rings were treppaned using a purpose ground too that had the radius of the cut ground on both faces (good old Quorn cutter grinder). The saddle is used to feed the tool in at a very low feed. the job needs lubrication more than coolant so Rockol was used in buckets full. Due to the tool being almost 5/8 inch long the machine speed was dropped to 36RPM.

The tool does look like a parting off tool just with a curve in the blade. The trick if there is one is to ensure that the tool dosnt dig in and rip the work out of the chuck, or off the face plate. For these I used a 12 inch face plate and bolted the billets down in six places with a rubbing block on the core so it wouldnt drop away once the cuts joined up in the middle of the billet. The tool was ground from 5/16 stelite as there was no call for carbide.

For any one thnking about cast aluminum T's I would recomend this method the wheels are solid and the rivetts took very welll through the spokes.

I have to say i really like the look of your little single cylinder oscilator. Nothing beats enginuity and that one has it in heaps nice litle engine.

kevin

**Bunkerbarge** · 22-01-2007

It was a bit of a ScrapHeap challenge!!

I once worked for a ski lift manufacturing company and we made our own flanges for mounting the wire sheeves. This involved trepanning 10mm thick plate at about 300mm diameter on a very large and very old lathe. As you say, if you fed it a bit too fast and it snagged you could end up wearing it.

Consequently I have never been a great advocate of the technique!!!

kevingambrell · 22-01-2007

Itl do that!

If you want a hard to turn part try a lump of anealed copper that wants to be faced off and turned to diameter! its horrible.

I asked a friend if he had any ideas to ease the grabbing he reconed tallow or at a pinch cows milk as a coolant/lubricant and to his credit the cows milk worked.

kevin