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laalratty:106099 wrote:Really does look excellent, the standard of work looks very high indeed.
Thank you!
I've been sorting out the gear lever arrangement. Here's a view through the cab door way.
The pins on the ends locate the levers in the right position. The knobs in the middle are for fingers to push/pull the levers. The two outer levers are forward (nearest), and reverse. Each lever has an in-gear position and a out-of-gear position. The two inner levers are for the different ratios. First - Neutral - Third, and Neutral - Second.
In the picture the loco is in First gear, but not in either Forward or Reverse. This way the loco can be pushed along
Last edited by dewintondave on Sun Feb 09, 2020 3:14 am, edited 1 time in total.
Had a great run yesterday. The run was to test the huge new muffler / silencer box attached to the cab firewall. There's so much expansion, that the exhaust gasses are quite cold exiting the exhaust stack. The muffler is very effective, there's little exhaust noise. However, there's a lot of mechanical noise from the motor itself, and there's a ringing noise from the muffler as it flexes, I'll put a stay in the middle to stop it.
The video was taken shortly after starting, I was draining off the oil until the good stuff started coming through, then reconnected a tube to the primary gearbox. I topped-up the fuel tank three times with the engine running. I felt like the run was about an hour. The loco went up and down the short section of track in all three gears, third is really rather rapid!
I measured some temperatures during the run with my eBay IR handheld thermometer:
I got cylinder head temperatures of 150 - 190 deg. C (300 - 370 deg. F).
And, the muffler box itself was only 70 deg. C (160 deg. F), which is lucky as it's only soft-soldered.
The motor wouldn't start with the exhaust stack fitted, so I replaced it once running. It's a slide-fit in the muffler
Last edited by dewintondave on Sun Feb 09, 2020 3:21 am, edited 1 time in total.
Very, Very Impressive.
Regarding the noise from the muffler. You could try attaching a small bit of lead or similar to the side. All that you may need to do is stop the metal vibrating at a certain frequency to stop the noise. The small additional bit of dense material will change the frequency and the noise may change or disappear.
(car manufacturers use this technique to stop strange resonations in vehicles.)
If at first you don't succeed, use a bigger hammer!
Big Jim:106329 wrote:Very, Very Impressive.
Regarding the noise from the muffler. You could try attaching a small bit of lead or similar to the side. All that you may need to do is stop the metal vibrating at a certain frequency to stop the noise. The small additional bit of dense material will change the frequency and the noise may change or disappear.
(car manufacturers use this technique to stop strange resonations in vehicles.)
I've been having doubts about reusing the engine oil in the gearbox. With the old set-up the oil came from the very hot muffler. With the new set-up it's a lot cooler and solid droplets of water come down the tube with the oil.
I removed the lower gearbox cover, and this is what I found: The grey particles are metal fragments. I spent hours deburring these gears by hand when I made them.
All the muck and gunk wiped off easily with a paper towel. There is evidence of light erosion from where the oil sits in the trough, but no red rust.
Last edited by dewintondave on Sun Feb 09, 2020 3:24 am, edited 1 time in total.
dewintondave:106343 wrote:I've been having doubts about reusing the engine oil in the gearbox.
Hi Dave,
I wouldn't let used engine oil near a gearbox in a fit.
Any oil that has been through an IC engine has combustion products in it, some of which can react with water to form acid. Probably the source of the etching you are seeing.
I'd build a separate closed sump for the gears and let the engine oil drip on the ballast to keep the weeds down........
GTB:106344 wrote:I wouldn't let used engine oil near a gearbox in a fit.
Nicely put
I just need to seal the cover with some sealant to keep oil from dripping out, and then use some mineral oil. I'm thinking of extending the cover downwards in the centre and incorporate a magnet to attract metal fragments
Last edited by dewintondave on Sun Feb 09, 2020 3:26 am, edited 1 time in total.
I experienced a technical issue with the engine the other day. The engine started running rough, fuel mix was spitting out through the carburettor, then the engine stalled. Afterwards there was minimal compression. I found the solution on this excellent forum:
A great run yesterday evening up and down a short section of the railway line. For the first time I could stand back and watch the loco run with the clutch held in position. With the head-on sunshine the exhaust smoke looked great and voluminous. The loco was run in 2nd gear all the way, a scale 10 mph.
The engine was run without the rocker cover so I could see what was going on. I'm giving the rocker gear a squirt of fuel, to oil it before each run now.
Someone on the above aircraft forum was not believing that 5000 rpm was still an idling speed, but, it is for R/C car engines. Here is the throttle position with the engine actually running, it won't run any slower.
During the run.
1:30 video of the run once up and down the line at 10 mph
Last edited by dewintondave on Sun Feb 09, 2020 3:45 am, edited 1 time in total.
Thank you. I'm very pleased with it.
Potassium Nitrate takes me back to when I was a youth.
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The roof was easier to form than I thought it would be.
I'm starting to think about painting the loco. Last week I test painted the exhaust stack with automotive spray paint intended for painting engine blocks. I "stoved" it in the oven for one hour at 115 deg C, then left it to cool overnight. Before and after that I had been baking it in the summer sun all day. I ran the loco this morning to test the paint, it survived ok. With my arrangement mainly water-like droplets come out of the exhaust. I think I'll apply some sort of wax to the horizontal surfaces where these droplets strike
Last edited by dewintondave on Sun Feb 09, 2020 3:48 am, edited 1 time in total.
Here is the spring loaded clutch lever mechanism, and the new exhaust drain pipe. The pipe passes by the rear axle and central drive shaft and drops the oil and condensate onto the track sleepers.
Last edited by dewintondave on Sun Feb 09, 2020 3:51 am, edited 1 time in total.
I bought a replacement rocker cover OS FS-30 spare part on eBay as I couldn't bear drilling a hole in the original. (I think OS FS-20, 26, and 30 are all the same external size) It's for a breather pipe, and I might use it for squirting some fuel in before each run to keep everything well lubricated. The cover is aluminium.
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I'm going to cut some ventilation holes in the bonnet at the back and use an electric cooling fan to push air over the engine and out of the front! Well, that's the plan.
The loco will soon be at the painting stage.
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Today I cut-out the ventilation opening on the side of the loco, and have soldered a stainless steel mesh grille over it. I was going to cut one on either side, but perhaps an asymmetric look isn't so bad. This way is more discreet as it isn't so easy to see inside.
Last edited by dewintondave on Sun Feb 09, 2020 3:55 am, edited 1 time in total.
That looks good.
TBH I've been thinking the bonnet looked very plain and "un-diesel-like"! So aside from the technical requirement IMO it improves the aesthetics as well.
You could put one towards the front on the other side, to increase ventilation without adding visibility?
philipy:107658 wrote:That looks good.
TBH I've been thinking the bonnet looked very plain and "un-diesel-like"! So aside from the technical requirement IMO it improves the aesthetics as well.
Yes, it's supposed to have louvered doors on the sides, but I'm too chicken / lazy. It was a bit of a mission cutting the cut-out, and laziness took it's toll again. There's going to be a fan above the flywheel / clutch blowing air over the engine and out from where the radiator would be. Air can be entrained from the new ventilation opening and from underneath - between the frames. I'm not a serious modeller, I quite like a toy like appearance. This project has been going on for far too long now, it's into the 3rd year now
Last edited by dewintondave on Sun Feb 09, 2020 4:40 am, edited 1 time in total.
As I'm waiting for the cooling fan. I decided to add a headlight to the loco. This light was made from the lens, reflector, and bulb assembly of a small torch (flashlight). I'm fond of brass, so I'm thinking of keeping it polished. The back plate is steel, and that can be painted.
It's surprising how long it took to make. The outer shell is 0.5mm brass sheet and had to be annealed and rolled around a former. Then it had to be wired closed and then silver brazed. The 1.2mm brass end pieces had to be cut-out, then they were soft soldered to a chucking piece, then turned to size to fit the outer shell. They were then silver brazed one at a time into the shell and turned on the lathe. The ends were drilled and bored for the reflector and lens.
This is a large light. It officially fell off a much larger NZR locomotive, and was pressed into service.
Last edited by dewintondave on Sun Feb 09, 2020 4:43 am, edited 1 time in total.
I have only contributed to this thread once before and can only repeat what I said then.... this has been one incredible project and I have no ability to emulate your skills with metal or IC power.
Your understanding of the materials, process and manufacture have been second to none, even the descriptions have been outstanding.
My congratulations on (almost) completion of the model. Please show the loco in its final painted state before you close.
The best things in life are free.... so why am I doing this?