adrian
Flying Squad
I did spot these a while ago, whilst interesting I don't think they have a 4-bolt LMS return crank option available.
7mm David Andrews Princess - 6206 Princess Marie Louise
- Thread starter Rob Pulham
- Start date
Rob Pulham
Western Thunderer
Hi Ian,
I did use loctite thread lock on them - the blue stuff that can be removed if needed but perhaps I need to add a drop of the green more permanent stuff.
The crank pin holes were already drilled and tapped 8BA when I received the kit which is a bit bigger than I would normally go for myself but I have made crank pins and bushes to suit.
Ian@StEnochs
Western Thunderer
Rob
IF you can screw the pin in and use the coupling rod bush to lock it that should be pretty solid, add retainer and I would think nothing could shift it!
Ian.
IF you can screw the pin in and use the coupling rod bush to lock it that should be pretty solid, add retainer and I would think nothing could shift it!
Ian.
OzzyO
Western Thunderer
Hello Rob,
if you used Loctight to lock the screws in place and then soldered the return crank in place you could have broken the Loctight bond. As heat is about the only thing that will brake the Loctight bond. I believe that goes for all of them. You could have a look on the Loctight chart as there could be one or two that are OK in the presence of heat as the live steam boys/girls use some of them.
ATB
OzzyO.
if you used Loctight to lock the screws in place and then soldered the return crank in place you could have broken the Loctight bond. As heat is about the only thing that will brake the Loctight bond. I believe that goes for all of them. You could have a look on the Loctight chart as there could be one or two that are OK in the presence of heat as the live steam boys/girls use some of them.
ATB
OzzyO.
Rob Pulham
Western Thunderer
Thanks Paul,
I was aware of heat being used to free off Loctited joints so I had made sure all was well before adding the Loctite but thanks for the heads up.
I was aware of heat being used to free off Loctited joints so I had made sure all was well before adding the Loctite but thanks for the heads up.
Rob Pulham
Western Thunderer
The last week and a bit of modelling time has been spent tracking down shorts on the tender and isolating them. This has required me making a number of additional bushes and delrin/acetal washers.
I also had to rethink the way that I had mounted the two U shaped brackets which fit across under the tender. Unthinkingly I had mounted them in the same way as on the MOK Stanier tender using small pieces of brass angle drilled and tapped for 14ba screws. Sadly when assembled these frames touch the brakes which although the shoes are insulated the hangers are not and between the two breached the insulation between tender chassis and body.
I made up some wire supports and then shortened the brackets to clear the outer frames. Below are a couple of shots of the sets that I used to get them soldered vertical to the brackets and then cut them off to the right size. I read recently on one of the forums someone say that you cannot have too many engineers clamps. I agree wholeheartedly although when used as soldering aids they do have a tendency to rust. I do have a cunning plan to get around that, I have a length of brass bar that I have had for about 10 years which will be just enough to make a pair of brass jawed clamps which shouldn't rust.
I used the Expo pliers that I recommended recently to bend the corners pretty uniformly.
I also had a feeling that the washers which I had used to reduce the side play in the axles, might have been bigger than the insulation gaps in the wheel hubs thus creating a short, hence my making the delrin washers.
I also had to rethink the way that I had mounted the two U shaped brackets which fit across under the tender. Unthinkingly I had mounted them in the same way as on the MOK Stanier tender using small pieces of brass angle drilled and tapped for 14ba screws. Sadly when assembled these frames touch the brakes which although the shoes are insulated the hangers are not and between the two breached the insulation between tender chassis and body.
I made up some wire supports and then shortened the brackets to clear the outer frames. Below are a couple of shots of the sets that I used to get them soldered vertical to the brackets and then cut them off to the right size. I read recently on one of the forums someone say that you cannot have too many engineers clamps. I agree wholeheartedly although when used as soldering aids they do have a tendency to rust. I do have a cunning plan to get around that, I have a length of brass bar that I have had for about 10 years which will be just enough to make a pair of brass jawed clamps which shouldn't rust.
I used the Expo pliers that I recommended recently to bend the corners pretty uniformly.
I also had a feeling that the washers which I had used to reduce the side play in the axles, might have been bigger than the insulation gaps in the wheel hubs thus creating a short, hence my making the delrin washers.
Rob Pulham
Western Thunderer
Since my last post I have been beavering away identifying and curing the shorts on the tender which I am happy to say that I have done.
As with many things in life getting there required at least one side project. During last Thursday’s GOG online modellers meeting the consensus was that I really needed to dig my multimeter out of the depths of the shed. On friday morning I bit the bullet and started to pull out plastic stacking boxes (having first removed the lawn mower, petrols cans, oak kitchen cabinet doors and finally my router table). An hour and a half later I had retrieved one of my two multimeters and put everything back.
Sadly the one that I found was the one with the missing probe, the wire was there but the common probe which had broken off in the dim and distant wasn’t with it. Before embarking on making a new probe I fitted a new battery to test that it still worked which thankfully it did. The metal section of the probe was made from a length of brass rod which sat atop my useful bits box on the workbench and I quickly drilled one end to accept the wire and turned a step onto the other to fit snugly into the yet to be made insulated delrin handle.
I didn’t take photos along the way but this is the finished article alongside the original ‘live’ probe.
Once I had it I reassembled the tender chassis test along the way without find any further shorts.
As with many things in life getting there required at least one side project. During last Thursday’s GOG online modellers meeting the consensus was that I really needed to dig my multimeter out of the depths of the shed. On friday morning I bit the bullet and started to pull out plastic stacking boxes (having first removed the lawn mower, petrols cans, oak kitchen cabinet doors and finally my router table). An hour and a half later I had retrieved one of my two multimeters and put everything back.
Sadly the one that I found was the one with the missing probe, the wire was there but the common probe which had broken off in the dim and distant wasn’t with it. Before embarking on making a new probe I fitted a new battery to test that it still worked which thankfully it did. The metal section of the probe was made from a length of brass rod which sat atop my useful bits box on the workbench and I quickly drilled one end to accept the wire and turned a step onto the other to fit snugly into the yet to be made insulated delrin handle.
I didn’t take photos along the way but this is the finished article alongside the original ‘live’ probe.
Once I had it I reassembled the tender chassis test along the way without find any further shorts.
Rob Pulham
Western Thunderer
Then I connected the loco and tender together and it immediately tripped out the controller and so I started a further round of troubleshooting. First I removed the bogie and after coffee I went back into our cloakroom where I have temporarily set up my test board. This room is west facing so gets sunlight mostly in an afternoon but it's below ground level as the path outside the window is cut into the embankment and so doesn't get quite as much natural light unless the sun is really high in the sky and it's late afternoon.
Now one of the suggestions from Thursday nights meeting besides dig out the multimeter was to try hunting for shorts in the dark as sparks are easier to see. As I went in for further testing I forgot to turn the light on and so the room was a little gloomy. This proved to be a benefit, because as soon as I moved the bogie on it's own, I noted a spark which I wouldn't have seen with the light on. I noted that the guard irons were quite close to the rails and may have caused shorts on curves so they were adjusted and then further examination showed that I had fallen foul of the etched washer/hub insulation again. A further check of the trailing tuck revealed the same issue. I had a few spare insulated washers that I had turned when working on the tender but they proved to be too thick even after turning/milling down the axle bushes.
I was initially going to make some up by using a hole punch to cut holes in some styrene sheet and then snip of /file them into circles. By good fortune a video that I had seen some time ago that was lurking in my memory surfaced on my Youtube feed. After rewatching it I decided to have a go at pressure turning a number of washers all at once.
Now unless you want really big washers the process is a little wasteful because you need enough stock to hold onto to drill the centre hole. I chose to cut some 0.5mm styrene sheet into 20mm x 20mm squares aiming for a finished size of 10mm diameter. You also need some scrap to hold the parts and one of them becomes almost sacrificial.
The first step is to grip the styrene squares between the two pieces of scrap material.
I used a 1" G clamp and a small engineers clamp to hold them all together to drill a 5mm hole through all the parts. This was to allow clearance on the 3/16 (4.7mm) axles. At this point you transfer the whole set up to the lathe before releasing the clamps.
I created the above set up which consists of a 22mm piece of Delrin in the collet (I had to turn a stub down to fit in a 16mm collet which is the largest ER25 collet that I have). This had a 5mm hole drill partially through it. At the tailstock end is another piece of 22mm Delrin which has had a 60 degree cone turned in the back so that it fits on a live centre then a short section turned down to 10mm to allow the tool to clear the workpiece(s) again it has a 5mm hole through it. Then a length of 3/6 rod was passed into the hole in the mandrel in the collet chuck and the parts fed onto it, before removing the clamps. Lastly the live centre is wound tightly against the parts which squash and grip all the parts for turning and locked.
The next step was to turn down the sacrificial scrap support until all the parts start to be turned. My sacrificial scrap was plastic which has a layer of aluminium either side of it and I found that the most depth of cut I could manage was 0.25mm per pass otherwise the parts started to slip. I started turning with a carbide tipped bit until it would no longer fit, then I changed to high speed steel grooving tool that I had ground for another job some time ago.
One piece of advice given in the video was to make sure that you were using a sharp tool for the final pass to help prevent the tool from rolling the edges of one part over onto the next.
These are the finished parts and they are all really crisp, aside from the one that was nearest the left hand piece of scrap which had a small burr around the edge (visible at the corner of the ruler). This burr was easily scraped off with a scalpel blade.
Now one of the suggestions from Thursday nights meeting besides dig out the multimeter was to try hunting for shorts in the dark as sparks are easier to see. As I went in for further testing I forgot to turn the light on and so the room was a little gloomy. This proved to be a benefit, because as soon as I moved the bogie on it's own, I noted a spark which I wouldn't have seen with the light on. I noted that the guard irons were quite close to the rails and may have caused shorts on curves so they were adjusted and then further examination showed that I had fallen foul of the etched washer/hub insulation again. A further check of the trailing tuck revealed the same issue. I had a few spare insulated washers that I had turned when working on the tender but they proved to be too thick even after turning/milling down the axle bushes.
I was initially going to make some up by using a hole punch to cut holes in some styrene sheet and then snip of /file them into circles. By good fortune a video that I had seen some time ago that was lurking in my memory surfaced on my Youtube feed. After rewatching it I decided to have a go at pressure turning a number of washers all at once.
Now unless you want really big washers the process is a little wasteful because you need enough stock to hold onto to drill the centre hole. I chose to cut some 0.5mm styrene sheet into 20mm x 20mm squares aiming for a finished size of 10mm diameter. You also need some scrap to hold the parts and one of them becomes almost sacrificial.
The first step is to grip the styrene squares between the two pieces of scrap material.
I used a 1" G clamp and a small engineers clamp to hold them all together to drill a 5mm hole through all the parts. This was to allow clearance on the 3/16 (4.7mm) axles. At this point you transfer the whole set up to the lathe before releasing the clamps.
I created the above set up which consists of a 22mm piece of Delrin in the collet (I had to turn a stub down to fit in a 16mm collet which is the largest ER25 collet that I have). This had a 5mm hole drill partially through it. At the tailstock end is another piece of 22mm Delrin which has had a 60 degree cone turned in the back so that it fits on a live centre then a short section turned down to 10mm to allow the tool to clear the workpiece(s) again it has a 5mm hole through it. Then a length of 3/6 rod was passed into the hole in the mandrel in the collet chuck and the parts fed onto it, before removing the clamps. Lastly the live centre is wound tightly against the parts which squash and grip all the parts for turning and locked.
The next step was to turn down the sacrificial scrap support until all the parts start to be turned. My sacrificial scrap was plastic which has a layer of aluminium either side of it and I found that the most depth of cut I could manage was 0.25mm per pass otherwise the parts started to slip. I started turning with a carbide tipped bit until it would no longer fit, then I changed to high speed steel grooving tool that I had ground for another job some time ago.
One piece of advice given in the video was to make sure that you were using a sharp tool for the final pass to help prevent the tool from rolling the edges of one part over onto the next.
These are the finished parts and they are all really crisp, aside from the one that was nearest the left hand piece of scrap which had a small burr around the edge (visible at the corner of the ruler). This burr was easily scraped off with a scalpel blade.
Yorkshire Dave
Western Thunderer
I have about four multimeters around the house - the largest one kept aside purely for mains testing. However, if you intend using your multimeter for mains testing I would recommend purchasing a new set of probes.
Of my remaining trio, one forms a permanent part of my modelmaking toolkit - readily available to check for potential shorts during building, testing pickup and lighting circuits and layout wiring.
Of my remaining trio, one forms a permanent part of my modelmaking toolkit - readily available to check for potential shorts during building, testing pickup and lighting circuits and layout wiring.
OzzyO
Western Thunderer
Hello Rob,
a nice job turning the bushes. You can also do them by turning a length of rod to the I/D of the washer and die cutting a screw thread for a nut at the open end along with a centre in the end. Doing it this way you produce less scrap and the holder can be used time and time again.
The rule looks a bit odd with a 1.5ish first 1mm on the rule, is the other side the same? If it is you could grind the end to the correct size. I've just noticed that it says 0.5mm above the bottom scale.
ATB
OzzyO.
PS. you can buy new test leads from Temu.
a nice job turning the bushes. You can also do them by turning a length of rod to the I/D of the washer and die cutting a screw thread for a nut at the open end along with a centre in the end. Doing it this way you produce less scrap and the holder can be used time and time again.
The rule looks a bit odd with a 1.5ish first 1mm on the rule, is the other side the same? If it is you could grind the end to the correct size. I've just noticed that it says 0.5mm above the bottom scale.
ATB
OzzyO.
PS. you can buy new test leads from Temu.
Last edited:
Rob Pulham
Western Thunderer
Hi Paul,
I can use the two bits of delrin many times but the bits of scrap that are used to push the styrene pieces together are sacrificial or at least one is. I could use the other one again as the top as long as I drill through the hole at the same size or bigger.
Re the ruler I don't actually use it for measuring anything. I am not sure where they came from but I had two or three. the reason it's so short is that I needed some really thin parallels, so I cut them down to fit in my mill vice. Since then I have cut a couple of the pieces down long ways so that they can be used as packing pieces when I need to lift something in the mill vice jst a small amount.
I used to have a couple of 5p pieces that I used to show scale in photos but had to use them for car parking change now the 'useless' ruler has a purpose.
I can use the two bits of delrin many times but the bits of scrap that are used to push the styrene pieces together are sacrificial or at least one is. I could use the other one again as the top as long as I drill through the hole at the same size or bigger.
Re the ruler I don't actually use it for measuring anything. I am not sure where they came from but I had two or three. the reason it's so short is that I needed some really thin parallels, so I cut them down to fit in my mill vice. Since then I have cut a couple of the pieces down long ways so that they can be used as packing pieces when I need to lift something in the mill vice jst a small amount.
I used to have a couple of 5p pieces that I used to show scale in photos but had to use them for car parking change now the 'useless' ruler has a purpose.
Rob Pulham
Western Thunderer
It's been getting on for six weeks since my last update on HRH. I haven't been idle and the process of eliminating shorts has been a journey of education, frustration and determination to not let it beat me.
Starting with a belt and braces approach I remade the drawbar in Delrin.
Next, having already added insulated washers to the wheels which are insulated at the hub I turned my attention to the driver which are rim insulated. I had previously made inner balance weights from Nickel sheet and although I had stuck them to the wheels with epoxy I was concerned that they be be helping to bridge the insulation gap should they touch the frames. My answer was to remake the balance weights for the insulated side from styrene.
Then I noted that the cross piece pf the rear inner frames was touching the tyres of the rear truck wheels. You can see the plate with the half etched rectangles in the image below.
A look at the instructions mentions the possible need to remove the half etched sections in case of shorts so the plate was removed and the rectangles removed.
Sadly, this didn't cure the problem so in the end I took of the outer sections leaving just the brace in the middle.
As it turned out that solved one problem but left another which will be the subject of another post
Starting with a belt and braces approach I remade the drawbar in Delrin.
Next, having already added insulated washers to the wheels which are insulated at the hub I turned my attention to the driver which are rim insulated. I had previously made inner balance weights from Nickel sheet and although I had stuck them to the wheels with epoxy I was concerned that they be be helping to bridge the insulation gap should they touch the frames. My answer was to remake the balance weights for the insulated side from styrene.
Then I noted that the cross piece pf the rear inner frames was touching the tyres of the rear truck wheels. You can see the plate with the half etched rectangles in the image below.
A look at the instructions mentions the possible need to remove the half etched sections in case of shorts so the plate was removed and the rectangles removed.
Sadly, this didn't cure the problem so in the end I took of the outer sections leaving just the brace in the middle.
As it turned out that solved one problem but left another which will be the subject of another post
3 LINK
Western Thunderer
Hi Rob,
I feel your pain, so much so I completely lost my mojo over the last loco I built. I just couldn’t solve why the loco ( American pick up method ) would stall on nearly every turnout. All my other locos would transverse the turnouts without trouble, I even had the layout operating at night with the lights out looking for a stray spark to no avail. I thought it was possibly a polarity problem with my wiring so spent a few back breaking hours under the layout, so frustrating as I find anything electrical a black art.
Anyhow, it turned out to be the front vacuum pipe was a fraction too long, and with a fag papers thickness would just touch the railhead . Yes I know maybe I should have noticed this earlier, easy to say in hindsight. So don’t give up is all I can say.
Martyn.
I feel your pain, so much so I completely lost my mojo over the last loco I built. I just couldn’t solve why the loco ( American pick up method ) would stall on nearly every turnout. All my other locos would transverse the turnouts without trouble, I even had the layout operating at night with the lights out looking for a stray spark to no avail. I thought it was possibly a polarity problem with my wiring so spent a few back breaking hours under the layout, so frustrating as I find anything electrical a black art.
Anyhow, it turned out to be the front vacuum pipe was a fraction too long, and with a fag papers thickness would just touch the railhead . Yes I know maybe I should have noticed this earlier, easy to say in hindsight. So don’t give up is all I can say.
Martyn.
Rob Pulham
Western Thunderer
Thanks Gents,
I am trying my best to treat it as a learning experience, and it is but it's far too easy to get despondent.
I am trying my best to treat it as a learning experience, and it is but it's far too easy to get despondent.
simond
Western Thunderer
As with most problems, shorts can be attacked with a ‘divide and conquer” strategy.
I’m presuming plastic spoked wheels with insulated crankpins generally - if you’re using metal wheels, with hub insulation, the valve gear will be live and the cylinders/motion brackets will need insulation from the frames. Kapton tape, tufnol and nylon screws are your friends. Metal wheels with rim insulation are similar to plastic spoked.
you’ll see on French level crossings, “un train peut en cacher un autre” - similarly, one short can hide another, if you have multiple shorts, you have to find them all, and they do hide behind one another…
where does it fail?
does it fail on my track / everybody’s track? If the latter, assume it’s the loco, not the track.
does only this loco fail on my track / do all locos fail on my track? If the latter, look at the track wiring, not the loco.
does it always and only fail on left hand bends (or one particular left hand bend)? It’s an interaction between loco and track.
does it fail when coupled to tender / always? Split tender & loco, check to see if either fails individually, or only when coupled
does it fail when coupled to certain other stock? I had one of these to sort out last month. Brass stock with live body, brass loco with live body, coupled one way no bother, coupled the other, sparks from coupling chain and buffers. Avoid having live chassis unless the body, buffers and couplings are insulated! It was ok for Triang, and Hornby, but it’s not ok for finescale models of mixed parentage! And it’s a likely chip disaster if you fit DCC.
ok, so perhaps we are down to a loco that still intermittently shorts.
remove body. Does it still short? If so, it’s in the chassis, if not, it’s likely a wheel touching the footplate or a splasher
remove bogies & pony trucks. Does it still short?
check resistance between rails and loco chassis. If chassis is live to one or other rail, fix that first.
repeat, but now slide wheels across to extremes of free play, both ways.
fit insulating spacer washers between wheels and chassis if wheels touching chassis.
If it still shorts try removing the valve gear & coupling rods.
disconnect the wires from the pickups to the motor so the pickups are not connected together.
Repeat sliding wheels from side to side
use a strip of paper to isolate the wheels on one axle from the rails, repeat for each axle, you should be able to identify whichever axle is touching.
hopefully this will identify 99% of issues.
I’m presuming plastic spoked wheels with insulated crankpins generally - if you’re using metal wheels, with hub insulation, the valve gear will be live and the cylinders/motion brackets will need insulation from the frames. Kapton tape, tufnol and nylon screws are your friends. Metal wheels with rim insulation are similar to plastic spoked.
you’ll see on French level crossings, “un train peut en cacher un autre” - similarly, one short can hide another, if you have multiple shorts, you have to find them all, and they do hide behind one another…
where does it fail?
does it fail on my track / everybody’s track? If the latter, assume it’s the loco, not the track.
does only this loco fail on my track / do all locos fail on my track? If the latter, look at the track wiring, not the loco.
does it always and only fail on left hand bends (or one particular left hand bend)? It’s an interaction between loco and track.
does it fail when coupled to tender / always? Split tender & loco, check to see if either fails individually, or only when coupled
does it fail when coupled to certain other stock? I had one of these to sort out last month. Brass stock with live body, brass loco with live body, coupled one way no bother, coupled the other, sparks from coupling chain and buffers. Avoid having live chassis unless the body, buffers and couplings are insulated! It was ok for Triang, and Hornby, but it’s not ok for finescale models of mixed parentage! And it’s a likely chip disaster if you fit DCC.
ok, so perhaps we are down to a loco that still intermittently shorts.
remove body. Does it still short? If so, it’s in the chassis, if not, it’s likely a wheel touching the footplate or a splasher
remove bogies & pony trucks. Does it still short?
check resistance between rails and loco chassis. If chassis is live to one or other rail, fix that first.
repeat, but now slide wheels across to extremes of free play, both ways.
fit insulating spacer washers between wheels and chassis if wheels touching chassis.
If it still shorts try removing the valve gear & coupling rods.
disconnect the wires from the pickups to the motor so the pickups are not connected together.
Repeat sliding wheels from side to side
use a strip of paper to isolate the wheels on one axle from the rails, repeat for each axle, you should be able to identify whichever axle is touching.
hopefully this will identify 99% of issues.
Yorkshire Dave
Western Thunderer
I can fully empathise - there's nothing worse than trying to trace electrical faults. Patience and logic is the key and once the fault(s) is(are) diagnosed you'll feel relieved and retain the causes in your memory bank not to be repeated on future builds.
To add to Simon's list I would also check to make sure the pickups (if fitted) are not being forced back against the chassis by the wheels and creating an inadvertant short.
As an aside, another weapon to have in your armoury is a few sheets of different thickness double sided copper clad PCB.
You can cut out replacement frame spacers, mounting points, etc and it can be scored to create insulation gaps with the advantage it still can be soldered.
Rob Pulham
Western Thunderer
Having solved the issue of the wheels touching the upper frame I then discovered that the wheels were touching the inside of the frames when going around a 6ft curve.
So I added some styrene insulation either side of the inner frames.
This cured the short problem but running trials revealed that although it would now go around 6ft curve without shorting it didn't do so reliably without the trailing truck derailing.
In an attempt to cure this I tried introducing some weight on to the trailing truck. I cut a couple of rectangles of lead and using a V block and a couple of different sized rods I created some weights that fit on top of the ruck over the axle.
I was getting low on lead but just this week we have had a couple of chimneys repointed and re-leaded as well as four wet verges I asked the roofer for the lead that they removed so I now have sufficient to see my days out I think.
So I added some styrene insulation either side of the inner frames.
This cured the short problem but running trials revealed that although it would now go around 6ft curve without shorting it didn't do so reliably without the trailing truck derailing.
In an attempt to cure this I tried introducing some weight on to the trailing truck. I cut a couple of rectangles of lead and using a V block and a couple of different sized rods I created some weights that fit on top of the ruck over the axle.
I was getting low on lead but just this week we have had a couple of chimneys repointed and re-leaded as well as four wet verges I asked the roofer for the lead that they removed so I now have sufficient to see my days out I think.
Richard Gawler
Western Thunderer
Rob I am so relieved to see some of the faults revealing themselves and you putting them behind you. I know for sure, I will never tackle a tender loco with "American style" wiring.
Rob Pulham
Western Thunderer
Hi Richard,
I have built several locos previously with american style pickup without issue but I have to be honest and say they were not as detailed as this build. Nor did they have cast wheels with telescopic axles which introduce their own complexities to the build.