7mm Coming soon to a forum near you... Sentinel Diesel
- Thread starter Dave
- Start date
Dave
Western Thunderer
I don't know about that kind of hydraulic. Before my time. 
I do know about these though and until recently I didn't know there was a kit for the 0-4-0 version, which I'll be building. That is until I read that Judith Edge kits were working on the chain drive (4wDH) version. So I called in on Mike and bought one of his 0-4-0 kits.
The Sentinel hydraulic shunter has got to be a design classic, IMHO. The first one was built in 1959 and production versions were available by 1963 yet 50 years on it still doesn't look dated. Some are still in use today. It's no wonder Hornby have chosen the chain drive version for a RTR model in 4mm as it has such a great timespan and can suit the 1960s BR modeller right up until the present day.
I think my first encounter with one of these machines was in the yard of C.F. Booth, Rotherham, where I got a cab ride in w/n 10288.
AJC
Western Thunderer
They're a really handsome design Dave, and as you say, one that's proved by the test of time - though they did actually win an industrial design award back in the day. The rod drive versions are particularly pleasing in my view (so much so I have my own EM 0-4-0). You build yours quicker than I build mine so I'll look forward to seeing how this one goes
Adam
Adam
Dave
Western Thunderer
I've started (so I'll finish 
)
The kit was one of Mike's early ones and there is no provision for compensation, therefore it's a DIY job.
The wheels are Slaters 3'7" coach wheels (7125) on 1/8th axles. I've soldered in a piece of scrap etch to give a knife edge for the axle (sleeved with some brass tube) to rock on. The other pieces were butted up to the tube and soldered in place before removing the tube and elongating the holes in the frames. This is to ensure the axle remains perpendicular to the frames as I don't trust myself to do a perfectly accurate filing job.
The gearbox and motor are from a long-abandoned 16mm narrow gauge project but as the grub screw for the axle gear was broken and seized, and therefore needed to be forced out, I may not be using it.
)The kit was one of Mike's early ones and there is no provision for compensation, therefore it's a DIY job.
The wheels are Slaters 3'7" coach wheels (7125) on 1/8th axles. I've soldered in a piece of scrap etch to give a knife edge for the axle (sleeved with some brass tube) to rock on. The other pieces were butted up to the tube and soldered in place before removing the tube and elongating the holes in the frames. This is to ensure the axle remains perpendicular to the frames as I don't trust myself to do a perfectly accurate filing job.
The gearbox and motor are from a long-abandoned 16mm narrow gauge project but as the grub screw for the axle gear was broken and seized, and therefore needed to be forced out, I may not be using it.
Steph Dale
Western Thunderer
I've started (so I'll finish
The kit was one of Mike's early ones and there is no provision for compensation, therefore it's a DIY job.
View attachment 17305
The wheels are Slaters 3'7" coach wheels (7125) on 1/8th axles. I've soldered in a piece of scrap etch to give a knife edge for the axle (sleeved with some brass tube) to rock on. The other pieces were butted up to the tube and soldered in place before removing the tube and elongating the holes in the frames. This is to ensure the axle remains perpendicular to the frames as I don't trust myself to do a perfectly accurate filing job.
View attachment 17307
The gearbox and motor are from a long-abandoned 16mm narrow gauge project but as the grub screw for the axle gear was broken and seized, and therefore needed to be forced out, I may not be using it.
Hehe, I really like the Sentinel/Rolls Royce diesels and am tempted every time someone posts on them. It'll be a shame if you can't get that grub screw out as those Model Loco gearboxes are superb; can't you find a way to drill and tap a hole or ask Grandspot for a spare?
Steph
Dave
Western Thunderer
Hi Steph,
I'm going to drill the grub screw out and then drill the axle through and pin it with a length of wire. The only problem is that I had to take the gearbox apart and before I could note where all the parts went it fell apart. I now have a tiny washer that I don't know which shaft, or which end to put it on. At the moment the gearbox is back together but minus the washer - I suspect they didn't put the washer in for fun and it isn't going to run smoothly without it.
I'm going to drill the grub screw out and then drill the axle through and pin it with a length of wire. The only problem is that I had to take the gearbox apart and before I could note where all the parts went it fell apart. I now have a tiny washer that I don't know which shaft, or which end to put it on. At the moment the gearbox is back together but minus the washer - I suspect they didn't put the washer in for fun and it isn't going to run smoothly without it.
JimG
Western Thunderer
Hi Steph,
I'm going to drill the grub screw out and then drill the axle through and pin it with a length of wire. The only problem is that I had to take the gearbox apart and before I could note where all the parts went it fell apart. I now have a tiny washer that I don't know which shaft, or which end to put it on. At the moment the gearbox is back together but minus the washer - I suspect they didn't put the washer in for fun and it isn't going to run smoothly without it.
Dave,
I suspect that the washer might have been on the shaft holding the worm gear to keep that gear in proper alignment with the worm, especially if the worm gear's teeth are curved to match the radius of the worm.
Jim.
Steph Dale
Western Thunderer
Correct!
Dave
Western Thunderer
The washer appears to have come from the first shaft in the gearbox, the one with the nylon gears. There is nothing holding the worm in alignment than the bearings in the motor. I've had it apart and fitted the errant washer and have also drilled out the grub screw and the axle.
Tomorrow I'll stick some wires on it and connect some power to test the motor. Fingers crossed that it works...
Tomorrow I'll stick some wires on it and connect some power to test the motor. Fingers crossed that it works...
Steph Dale
Western Thunderer
Great stuff!
Dave
Western Thunderer
A little more progress.
The basics of the outside frames, running plate, and buffer beams have been assembled and the cab floor has been soldered to the inner frames.
This reading the instructions malarkey is taking some getting used to but that's all there is - no exploded diagram or anything of the sort. Still, it's going together well so far; I've not had to file or grind anything beyond the basic removing the joinings to the etch.
The trial fit of one buffer has revealed that springing is not an option with the buffers I have chosen. I can't remember exactly what they are but they are some sort of heavy duty wagon buffer from Slaters. The kit as it comes does not include buffers, wheels, couplings, motor or gearbox.
The basics of the outside frames, running plate, and buffer beams have been assembled and the cab floor has been soldered to the inner frames.
This reading the instructions malarkey is taking some getting used to but that's all there is - no exploded diagram or anything of the sort. Still, it's going together well so far; I've not had to file or grind anything beyond the basic removing the joinings to the etch.
The trial fit of one buffer has revealed that springing is not an option with the buffers I have chosen. I can't remember exactly what they are but they are some sort of heavy duty wagon buffer from Slaters. The kit as it comes does not include buffers, wheels, couplings, motor or gearbox.
Dave
Western Thunderer
The buffers have been added to the frames and I've assembled the engine cover. The grille is made by laminating 3 parts together to give that distinctive grid. The sentinel sword is still to fit but I may leave this until the loco is painted and glue it on as it's in nickel silver and the real thing was either chromed or stainless steel so it's best left unpainted.
As it stands the cover isn't fitted to the frames and has been designed to be removable. Four 14B A and one 8BA nuts and screws hold it to the chassis when fitted, which is a neat way of doing it, rather than having to solder the whole to the frames. The cover was built on the frames by fastening the base to the frames and soldering the nuts captive to the base. Then a smear of grease was applied to the base to prevent any stray solder from fixing the whole to the frames before soldering the cover to the base and grille.
Some prototype inspiration:
Crossley's scrapyard in Shipley, sometime in the late 1990s IIRC. The loco was ex-British Coal Kellingley Colliery and was one of three supplied there. I'm fairly sure that this was formerly 108, the same one pictured in the official photo that I posted earlier.
As it stands the cover isn't fitted to the frames and has been designed to be removable. Four 14B A and one 8BA nuts and screws hold it to the chassis when fitted, which is a neat way of doing it, rather than having to solder the whole to the frames. The cover was built on the frames by fastening the base to the frames and soldering the nuts captive to the base. Then a smear of grease was applied to the base to prevent any stray solder from fixing the whole to the frames before soldering the cover to the base and grille.
Some prototype inspiration:
Crossley's scrapyard in Shipley, sometime in the late 1990s IIRC. The loco was ex-British Coal Kellingley Colliery and was one of three supplied there. I'm fairly sure that this was formerly 108, the same one pictured in the official photo that I posted earlier.
Dave
Western Thunderer
Much progress has been made today.
The cab is on, as are the handrails at one end and the fuel tank at the other.
Fitting the cab doors is proving to be difficult so I've given up for the day.
The really difficult part will come when I attempt to quarter the axles as it can only be done with the axles already fitted. I've made a start on laminating the flycranks but the axle holes will need opening out before I can attempt any trial-fittings.
Another prototype shot, this time a loco built to the same design but by Sentinel agents Thomas Hill. I took this photo in 1995 at Stanton ironworks.
The cab is on, as are the handrails at one end and the fuel tank at the other.
Fitting the cab doors is proving to be difficult so I've given up for the day.
The really difficult part will come when I attempt to quarter the axles as it can only be done with the axles already fitted. I've made a start on laminating the flycranks but the axle holes will need opening out before I can attempt any trial-fittings.
Another prototype shot, this time a loco built to the same design but by Sentinel agents Thomas Hill. I took this photo in 1995 at Stanton ironworks.
Dave
Western Thunderer
Leaving the body for now, I've turned my attention to the frames and, amazingly, it now runs! OK so it shouldn't be that amazing but the thing is it ran first time - no fettling, no taking it apart and putting it back together at all.
It's all the more amazing because I was worried about the quartering screwing it all up.
As I said in the previous post, the holes in the cranks needed to be opened out but I didn't do that. I reckoned that opening them out to the size of the axle extensions would give me a fixed size hole, i.e. the drill size. By turning the axle extensions down and checking the fit regularly I was able to take off just enough to be able to make an interference fit and so the cranks are pressed on so tight that when the axle is held in a vice I cannot turn the crank by fingers, or even a pair of pliers. Having pressed the cranks on I turned axle extensions so that they were flush with the outer face of the cranks.
To fix the rods I ran a 14BA tap down the holes in the cranks but couldn't find any screws long enough and so abandoned that idea and used the pins supplied with the kit. These were glued into the cranks and left loose on the rods.
Then it was time to fit the rod/crank assemblies... I used cyano glue on one side and pushed the cranks on and left for a few minutes to let the glue harden. I then put pressure on the chassis with a finger and thumb and pushed it up and down to check it was still free-running (I had removed the pin from the drive gear). Then the other side's crank/rod assembly was fitted using Loctite Sleeve and Bearing Retainer, so I would have some time to make adjustments. As it happened I got it bang on first time. I gave the Loctite a couple of minutes and then pushed the chassis in the same way again and it didn't appear to bind at all so I left it for a couple of hours to harden properly.
After that I pushed it without pressing down and it still ran fine so I replaced the pin in the drive gear, made and fitted some pickups and wired in a decoder. The bodywork was then fitted to test it on the layout and I can report that it ran perfectly.
The bodywork still needs the doors fitting and a few other odds and ends and the chassis needs the brake gear and the roller bearing caps putting on the rods. Then the other worry is glazing the cab.
It's all the more amazing because I was worried about the quartering screwing it all up.
As I said in the previous post, the holes in the cranks needed to be opened out but I didn't do that. I reckoned that opening them out to the size of the axle extensions would give me a fixed size hole, i.e. the drill size. By turning the axle extensions down and checking the fit regularly I was able to take off just enough to be able to make an interference fit and so the cranks are pressed on so tight that when the axle is held in a vice I cannot turn the crank by fingers, or even a pair of pliers. Having pressed the cranks on I turned axle extensions so that they were flush with the outer face of the cranks.
To fix the rods I ran a 14BA tap down the holes in the cranks but couldn't find any screws long enough and so abandoned that idea and used the pins supplied with the kit. These were glued into the cranks and left loose on the rods.
Then it was time to fit the rod/crank assemblies... I used cyano glue on one side and pushed the cranks on and left for a few minutes to let the glue harden. I then put pressure on the chassis with a finger and thumb and pushed it up and down to check it was still free-running (I had removed the pin from the drive gear). Then the other side's crank/rod assembly was fitted using Loctite Sleeve and Bearing Retainer, so I would have some time to make adjustments. As it happened I got it bang on first time. I gave the Loctite a couple of minutes and then pushed the chassis in the same way again and it didn't appear to bind at all so I left it for a couple of hours to harden properly.
After that I pushed it without pressing down and it still ran fine so I replaced the pin in the drive gear, made and fitted some pickups and wired in a decoder. The bodywork was then fitted to test it on the layout and I can report that it ran perfectly.
The bodywork still needs the doors fitting and a few other odds and ends and the chassis needs the brake gear and the roller bearing caps putting on the rods. Then the other worry is glazing the cab.
AJC
Western Thunderer
Nice work. Re; glazing. Does the kit come with a full-size CAD drawing like the 4mm one does? Or failing that, any drawing at all, even a 4mm one? The easiest approach might be to run off a couple of copies, tape them to a flat surface, tape the glazing over the top and cut around the lines. The really easy option - though it's a bit late in this case - is to use the etch as a template and cut the glazing in advance while the etch is still flat.
BTW, take a look at the window pillars for the front screens; these should be parallel, on my 4mm version they weren't. Easy enough to open out of course, but it was a bit of a fiddle to replace the appropriate edge of the beading in flattened copper wire.
Adam
BTW, take a look at the window pillars for the front screens; these should be parallel, on my 4mm version they weren't. Easy enough to open out of course, but it was a bit of a fiddle to replace the appropriate edge of the beading in flattened copper wire.
Adam
john lewsey
Western Thunderer
Very very nice