Wheel Nuts catching Pick - Ups

[Deem]

Hello

I have Hornby Class A1 Model Number R3086. I have replaced 2 sets of pick ups and today put brand new wheel set bought from Lendons of Cardiff.

Wheel nuts keep becoming loose and than they catch Pick ups and damaged them. I have already replaced 2 pick ups and both have been damaged or broken aren't straight because they get caught with nuts on the inside wheels.

I am uploading some pictures and maybe some one can help fix this problem.

[Deem]

I ran the loco without the pick ups by powering the motor directly, and nut sleeve haven't move yet.

[What About The Bee]

Nut retainer. Locktite 242 is one example.

A tiny little dab will do ya!

After you know everything fits together, remove the screw and place a very, very small amount of the nut retainer on the threads of the screw. Think micro grams here. Follow the directions about curing.

Problem solved

Bee

[Going Spare]

This appears to be the inner end of the crank pin. In UK-production days, it was shaped to fit in to a similarly shaped recess in the wheel boss to stop it rotating so check that it is in the correct position and pull it in to place flush with the wheel from the outside (having removed the screw and rods to avoid damage and taking care not to damage the smooth outer surface of the crankpin) and perhaps apply a small amount of superglue to keep it in place.

[Deem]

Very fiddly job, but will try tomorrow to see if I can sort that out, I am aware pick ups aren't that expensive and I bought these pick ups in bulk so I can upgrade some of my older Loco. Will update tomorrow or Friday when I get the chance to try to fix.

Any good quality Super Glue I should consider, Local round the corner shops or superstore super glues I find them useless.

[Rog RJ]

A small dab of nail polish or enamel paint on the thread works too.

[Deem]

It's not the thread which is the issue, it's the Spindle which have been secured in the green wheel which keep moving inward, towards the chassis and catching pick ups, if I can keep the spindle fixed in the green plastic wheel using some kind of glue so spindle doesn't become loose or move inward, I think that will fix the issue. Please correct me if I am wrong as in the terminology.

[Rog RJ]

I may be missing something here but if the motion work is assembled correctly with the correct nuts & bolts then the "nut" parts should be pulled into the back of the wheel, keeping it clear of the pickups. Thread locking should prevent the nut and bolt from loosening.

[threelink]

I occasionally had a similar problem with old Triang locos, where the crankpin screw worked loose allowing the retaining nut partially to unscew itself, come out of its recess in the wheel back and foul on the chassis. The cure was to glue the nut into its recess with a tiny dab of contact adhesive and use a small dab of acrylic varnish to lock the screw thread. The varnish did not prevent removal of the crankpin screw if required but was sufficient to prevent unwanted unscrewing. Worked like a charm.

[Deem]

I may be missing something here but if the motion work is assembled correctly with the correct nuts & bolts then the "nut" parts should be pulled into the back of the wheel, keeping it clear of the pickups. Thread locking should prevent the nut and bolt from loosening.

thanks ROJ, now you mention it, I can think at this stage, either I have wrong wheel set or some how by someone (maybe previous owner) have removed and installed incorrect bushes which goes between long side rod or coupling rod and main rod or connecting rod. I can see gap off maybe about 1 or 1.5 mm between bush and eccentric rod. Which explain why the spindle can travel inward and catch the pickups. Once I push the or squeeze the spindle in correct place loco runs beautifully again. Will look into that to confirm tomorrow.

 

 

 

 

[Deem]

Thanks threelink, bolt hold the all rods and bushes tight enough, but as I mentioned earlier that, there is gap between bush or spacer between main rod and connecting rod which now explain why and how nut part can move inward to catch pick ups.

[What About The Bee]

Deem

This all comes down to the following

1) if the round barrel of the shoulder screw can go through the green wheel, you need to fix the nut into the back of the green wheel with a bit of adhesive.

2) if the shoulder of the shoulder screw bottoms out on the green wheel, then any type of thread retainer will keep the shoulder screw from loosening on the nut

This is total sum of the problem. You can do both, of course. Affix the nut with adhesive to the green wheel AND use some thread retainer.

Bee

[threelink]

@Deem

Yes, missing spacers would explain why the crankpin screw/nut assembly can move inwards to foul the pick ups. Good luck in sorting this out.

[Deem]

Thanks everyone for your support

@threelink, spacer is present but I think it's wrong size. I took out my other Hornby FS R3086, spacer or bush (whatever you want to call) is different size to one I have on this problematic loco. My other FS spacer is roughly few millimetres higher or wider than, the one in this FS.

I may have to order condors but need to check with suppliers if the conrods comes with the spacer or bush when I buy them or I will have to make specially, when I travel to Pakistan 🇵🇰, I can make these in my brother work shop on lathe machine. Maybe make spare for future usage. I don't have mini lathe here otherwise I could have try making them here as well.

[ColinB]

To me it looks like the conrod wheel adaptor or whatever you call it, has pushed out at the back. I think as someone else says you just need to push it back. I add a bit of superglue on it before I push it back but make sure it locates properly. Surely your valve gear would have not tightened up correctly? If that doesn't work, they it might be necessary to get another set of wheels. I find on most of the second hand locos I buy, one has pushed out at the back.

[Deem]

Thanks ColinB.

I have figured out the issue and will try to explain tonight with pictures so I can get best advice accordingly.

[Deem]

I have searched the google to find a picture with UK steam engine parts with description, I have found this, so when we talk about the parts, at least we have the correct names.

Also note for moderator, if this breach any law please don't approve the picture.

Regards

[Deem]

So the issue is, centre wheel shaft which hold, coupling Rod - crankshaft and connecting Rod, have too much play which pushes the spindle inward, which than catches the pick ups. I try to use the plastic washer to reduce the gap but that is not enough, it's very late now so I will try tomorrow again with 2 washers to see that solve the problem before I replace the 3rd pick up.

[Deem]

[Deem]

Pictures have been uploaded so hopefully once approved everyone can see them.

Regards

[atom3624]

I thought the spacer should be between the coupling rod and the connecting rod?

Al.

[ntpntpntp]

I thought the spacer should be between the coupling rod and the connecting rod?

Al.

 

 

I agree. The metal spacer should be between the coupling rod and connecting rod, that way it allows clearance for the coupling rod pins and aligns the connecting rod with the piston rod. That plastic washer shouldn't be necessary.

Still doesn't explain why the crankpin is too long and apparently protruding from the back of the wheel though.

[threelink]

This is not a model with which I am familiar but it occurs to me that perhaps there should be a washer between coupling rod and wheel boss. If so, no plastic washer should be needed if the spacer is replaced in the correct position between coupling and connecting rods. If all washers/spacers are correctly in place and the crankpin screw/bolt still protrudes from the wheel back I would suggest that the wrong crankpin screw/bolt has been used.

[Deem]

Thanks, all, for your time and sharing your thoughts,

I had the spacer as you suggested initially, when I replaced the Valve gear. However when I took out my other FS which is factory fitted and I never touched that Loco, in that Loco spacer is above coupling rod and connecting rod, just like I have shown in these pictures. I think some how by previous owner or someone at some point had replaced or fitted incorrect spacer.

In factory fitted valve gear which I never opened or repaired, spacer height is about 1.5mm more compare to this problematic Loco spacer.

[atom3624]

I've R2687 Flying Scotsman and R2339 Mallard next to me.

I admit both have been 'serviced' on several occasions, but both run superbly.

Both have the spacer between coupling rods and connecting rod.

Plastic washers have been used on the inside of wheels, and located inside of the wheel, outside of the chassis for some locomotives.

Al.