Sylvian Tennant Posted June 7, 2015 Share Posted June 7, 2015 I have recently been modifying and weathering an old tender drive 8F. Just before I had painted it i give it a short test run and everything was working fine. However, once I had painted and weathered it I have now found that it barely runs and is very twitchy when it does. I have taken it apart, put it back together, cleaned as much as I could have off the wheels and connections but it's still struggles to run. I have localised the problem to the locomotive itself as the tender drive unit runs fine with other locomotives. The chassis block carries a current when it is switched on too but apart from that there is nothing much in the way of running. The modification wasn't a problem before as i have mentioned previously it was working prior to painting. (the modification itself involved drilling out the chassis and adding a brass 8ba screw and nut as per the comet models instructions). Has anyone else encountered this problem before and does anyone know what to do, save buying a new chassis (unless one is going free). Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 7, 2015 Author Share Posted June 7, 2015 Ahhh okay, I use gauge master oil to help loosening up after painting. The model itself comes without wipers and it wasn't something i have added to the model (for some reason the Margate 8F's where left without unlike the 9F and others.) I'll give the chassis a good once over with white spirit later. see if that helps. TY. Link to post Share on other sites More sharing options...
RMweb Premium uax6 Posted June 7, 2015 RMweb Premium Share Posted June 7, 2015 Did you remove the wheels from the axles? If you did, you may not have them quartered correctly..... Andy G Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 7, 2015 Author Share Posted June 7, 2015 The wheels have remained don their axels but there is some slight problems there. I've had another go at the wheels and bass washers inside with white spirit, but still nothing has improved. Link to post Share on other sites More sharing options...
Londontram Posted June 7, 2015 Share Posted June 7, 2015 The clue could be in what you said "I use gauge master oil to help loosening up after painting" To be fair if painting and weathering you shouldn't get any paint on any moving part, to do so then hope that a lubricant will make it OK is asking for trouble really. Clean off the moving parts as much as you can and try again. Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 7, 2015 Author Share Posted June 7, 2015 I'll give it another try but so far I've cleaned off a fair bit. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted June 8, 2015 RMweb Premium Share Posted June 8, 2015 I have taken it apart, put it back together, cleaned as much as I could have off the wheels and connections but it's still struggles to run. The chassis block carries a current when it is switched on too but apart from that there is nothing much in the way of running. Can you explain the meaning of these lines? Is the loco causing a short circuit, or is it open circuit? Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 8, 2015 Author Share Posted June 8, 2015 Sorry I'll try to rephrase them. I've taken the chassis apart and put it back together to see if I can identify a problem but everything seemed to be correct and in it's place. Originally I thought I could feel an electrostatic charge in the chassis block when I touched it, believing that there was some issue with the wheel connections. However this isn't the case. I thinking that it maybe something to do with the drawback connecting the tender to the locomotive. Link to post Share on other sites More sharing options...
DS239 Posted June 8, 2015 Share Posted June 8, 2015 I thinking that it maybe something to do with the drawback connecting the tender to the locomotive. I take it that you mean the drawbar,- this is often the cause of poor running if it is only making intermittent contact,check the 'jaws' at the rear where they make contact with the brass pin on the underside of the tender underframe,and also check the contact between the top of the drawbar and the bottom of the chassis block where it is held on by the shouldered screw. Sometimes the contact needs bending upwards a tad and the chassis cleaned of any grease/oil,sometimes the block needs to be cleaned back to bright metal. A final thought,- when you re-assembled the wheelsets into the chassis,did you put them all in the correct way round? With the insulated wheels on the right hand side,as looking from the cab. Link to post Share on other sites More sharing options...
RMweb Gold Barry Ten Posted June 8, 2015 RMweb Gold Share Posted June 8, 2015 You can tell a difference between a short and an electrical interruption by putting another loco on the same piece of track at the same time as the problem one. If the other loco also stops dead, it's a short; if the other loco keeps running, it's an interruption. Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 8, 2015 Author Share Posted June 8, 2015 sorry I have a computer which autocorrects badly and i never check my message before posting. I checked the wheels to make sure they were correct, i found out elsewhere about the pickups work for Hornby tender drive. I am suspecting it is the drawbar now more than anything. I modified it from the original design via the comet models way of drilling out the read of the chassis block and replacing the screw on the drawbar with an brass 8BA 1/2 inch screw. Unfortunately the spring had to take some modification too as it was slightly damaged in the process so it has been soldered to the drawbar, the fit is also very tight now. I might buy a new one from peters spares in all honesty. It is defiantly an interruption from what i can see, the tender unit works fine with other locos but the 8F still judders along with other tender units. If i jiggle the loco along the tracks or apply a little pressure to the rear of the chassis block it picks up intermitted but the performance is very jittery. Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 9, 2015 Author Share Posted June 9, 2015 cheers guys, I'll give the wire suggestion I try. Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 10, 2015 Author Share Posted June 10, 2015 problem i have encountered... I've tried soldering a piece of wire from the motor unit to the loco chassis block and the solder just will not take to it. Also I disassembled the loco chassis and tried different bits to the piece of wire I have now attached to the tender, the wheels pick up, the chassis block picks up the brass nut and screw pick up i believe even the drawbar picks up.... but put them together and nothing. Link to post Share on other sites More sharing options...
Sylvian Tennant Posted June 15, 2015 Author Share Posted June 15, 2015 The good news is I've managed to hardwire the loco and tender together and sort of get it working. But the bad news is the copper wire i've used is to very flexible so it is creating a lot of friction on the wheels and also not very springy which is still causing some jolty movements. Can anyone put forward a suggestion for a decent gauge or wire to use or anything the will be light and flexible? Link to post Share on other sites More sharing options...
10000 Posted June 15, 2015 Share Posted June 15, 2015 I've followed this thread and being the owner of several tender drives from early ones to the last produced I find they do need a bit more TLC than loco drive but are fairly simple in design and build so apart from motor burn out there is very little to stop them from running. So here is what I do with reluctant tender drives. Loco - strip the chassis down clean out the axle slots with meths/ipa or something similar. Clean the axles, if fitted with brass bearings be sure to move aside and try and clean under them. Wipe the axle slots/ axles with an oily rag - any more and it turns into a black goo after a period of running. Remove the drawbar make sure it and where it is attached to the chassis is oil free then if needed clean with a fibre pen. Clean the inside of the brass contacts on the drawbar with a fine emery cloth. If the drawbar has fine contacts on top make sure they are clean and the correct spacing otherwise they can cause a short on the tender. Reassemble and ensure it is free rolling with no binding. Tender - clean then lightly lube the gears clean pickup wheels and if fitted pickup strips. Clean pin that connects to drawbar and if upper draw bar contacts are used clean the plate they press on to. Check with direct power application. If all is OK the it should run with no problem Link to post Share on other sites More sharing options...
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