Dapol 122 running issue - wheels spinning?

[JohnR]

I recently acquired a 2nd hand Dapol 122 in OO. While one of the bogies works (I think the other simply has its drive shaft disconnected), the other one seems unable to move the unit - the wheels just spin on the track.

 

Has anyone experienced this before? 

[cessna152towser]

I had a Dapol 121 in 00 gauge, bought new.   After very little running, the wheels were intermittently spinning and when I opened it up the wheels of the bogie at one end were only turning slowly as the claw from the drive shaft had chewed up the plastic of the flexible coupling.    I disconnected the shaft to the offending bogie, but due to the weight of the model, the single bogie still driving the model had insufficient adhesion.   I raised the matter with the service address supplied in the Dapol paperwork but never got any response.  I sold it on eBay as a non-runner for around half what I originally paid.  A very disappointing model.

[dj_crisp]

56 minutes ago, JohnR said:

I recently acquired a 2nd hand Dapol 122 in OO. While one of the bogies works (I think the other simply has its drive shaft disconnected), the other one seems unable to move the unit - the wheels just spin on the track.

 

Has anyone experienced this before? 

 

Do you have the drive shaft connected for the other bogie?

 

I've now repaired 4 chassis and they all had the same problem with no movement to one of the bogies. Dapol have used a metal shaft and plastic knuckles (not sure thats the right term but hopefully you know what I mean). I think this is a fundamental flaw of their chassis.

 

I think grease gets in causing the shaft to slip resulting in no drive. The way I've fixed mine is to burr the metal shaft and super glue it to the knuckle. Seems to work. 

 

If you're missing the shaft this is available as a spare. It's not a tricky job to fix... my tip is to part unscrew the motor to allow you easily remove and fit the shaft..... you'll see what I mean ;)

 

Tbh the chassis is a bit OTT so needs all 4 driving.... especially compared to Bachmanns effort which IMO is much better on all counts.

 

Hope this helps

Will

[JohnR]

32 minutes ago, dj_crisp said:

 

Do you have the drive shaft connected for the other bogie?

 

I've now repaired 4 chassis and they all had the same problem with no movement to one of the bogies. Dapol have used a metal shaft and plastic knuckles (not sure thats the right term but hopefully you know what I mean). I think this is a fundamental flaw of their chassis.

 

I think grease gets in causing the shaft to slip resulting in no drive. The way I've fixed mine is to burr the metal shaft and super glue it to the knuckle. Seems to work. 

 

If you're missing the shaft this is available as a spare. It's not a tricky job to fix... my tip is to part unscrew the motor to allow you easily remove and fit the shaft..... you'll see what I mean ;)

 

Tbh the chassis is a bit OTT so needs all 4 driving.... especially compared to Bachmanns effort which IMO is much better on all counts.

 

Hope this helps

Will

 

I havent checked to see if the drive shaft is connected to the other bogie - I had read that it worked fine with one connected. I dont think the problem is due to a disconnected drive shaft on the remaining bogie - the wheels are turning - its almost as if theres not enough weight on that bogie. 

 

[dj_crisp]

4 minutes ago, JohnR said:

 

I havent checked to see if the drive shaft is connected to the other bogie - I had read that it worked fine with one connected. I dont think the problem is due to a disconnected drive shaft on the remaining bogie - the wheels are turning - its almost as if theres not enough weight on that bogie. 

 

 

I tried running just one bogie and performance for me was rubbish.i put it down to the internal gears of the spare bogie causing lots of drag. I can't see weight being the problem with it.

 

Does yours work fine on a rolling road?

 

I've also noticed that new the mechanism seems a bit tight so that could also be causing issues?

[Hal Nail]

The existing 121/122 thread does cover quite a few issues with the drive chain and peoples solutions. 

Edited July 26, 2022 by Hal Nail

[JohnR]

On 25/07/2022 at 10:49, dj_crisp said:

 

I tried running just one bogie and performance for me was rubbish.i put it down to the internal gears of the spare bogie causing lots of drag. I can't see weight being the problem with it.

 

Does yours work fine on a rolling road?

 

 

I've put it on the rolling road, and the wheels are turning, just as they are on the track, and as far as I can tell, the rollers are turning.

 

 

I've noticed that the drive shaft for the other bogie, while not attached is loosely spinning, and creating some noise, possibly some drag? Is it worth repairing this, or removing it altogether. 

 

[JohnR]

3 hours ago, Hal Nail said:

The existing 121/122 thread does cover quite a few issues with the drive chain and peoples solutions. 

 

I have to admit to being lazy and hoping someone could identify the issue without me having to go through the many pages of that thread!

[dj_crisp]

2 hours ago, JohnR said:

 

I've put it on the rolling road, and the wheels are turning, just as they are on the track, and as far as I can tell, the rollers are turning.

 

 

I've noticed that the drive shaft for the other bogie, while not attached is loosely spinning, and creating some noise, possibly some drag? Is it worth repairing this, or removing it altogether. 

 

 

The bogie working looks ok to me so I'd expect the "unpowered" one to be causing you grief and the bogie itself causing the drag.

 

The shaft seems very loose to me so I think it's worth taking it apart to see if the ends are broken or someone simply hasn't fitted it right and it's not in the centre of the flywheel. I could only get the shaft to fit by loosening the motor from the mount to allow enough flex to refit mine.

 

Be interested to see what's wrong on this one as it has subtly different problems to the ones I've fixed

[Tony Cane]

I have recently had to fix a Dapol 122 where both the plastic mouldings on the ends of onw drive shaft had split, thus removing all drive.

I presume that those of you that are removing one drive shaft to wiork with just one driven bogie are also removing the worm gear from the unpowered end. If not then you are trying to drag  two sets of wheels that are locked by the gearing.

 

The rolling road test will show that the driven bogie is fine as it in not trying the move the other bogie with the worm in place.

[JohnR]

23 hours ago, Balgrayhill said:

Hi John

 

I took the driveshaft and bogie gearing out of my 122 which cured some quite slow running, have you tried that?

 

 

 

Not yet - was hoping to find some photos or videos of how to disassemble that part, but lots of the images in the main 121/22 thread arnt available...

[JohnR]

I think i've got a deeper problem than that.

 

I've removed the worm and drive shaft from the non-working bogie, and those wheels now move freely.

 

However, I still have the same problem, it seems there is some movement of the wheels on the driven bogie, then they stop. The motor sounds as if it speeds up. I'm guessing that drive shaft is loose?

[Tony Cane]

The 122 I recently repaired had all four plastic ends of the drive shafts with splits in them. the only viable fix was to replace both drive shafts. the replacement shafts are a different design to those replaced, the shaft has milled on splines so should be putting less stress on the plastic parts.

[dj_crisp]

8 hours ago, JohnR said:

I think i've got a deeper problem than that.

 

I've removed the worm and drive shaft from the non-working bogie, and those wheels now move freely.

 

However, I still have the same problem, it seems there is some movement of the wheels on the driven bogie, then they stop. The motor sounds as if it speeds up. I'm guessing that drive shaft is loose?

 

 

It sounds like it - As Tony says replacing the drive shafts is an option or trying my fix of burring the shaft and super-gluing the plastic ends

 

good luck!

[JohnR]

18 hours ago, dj_crisp said:

 

 

It sounds like it - As Tony says replacing the drive shafts is an option or trying my fix of burring the shaft and super-gluing the plastic ends

 

good luck!

 

Having now checked my other 122 (also 2nd hand, but not properly tested until now) and my older 121(not been run for a few years over Covid), I think the drive shaft issue is endemic across all 3. 

 

Is it a case of super gluing the shaft to the plastic bearing then?  This one seems to function at first, but works loose shortly after operation. 

[dj_crisp]

8 hours ago, JohnR said:

 

Having now checked my other 122 (also 2nd hand, but not properly tested until now) and my older 121(not been run for a few years over Covid), I think the drive shaft issue is endemic across all 3. 

 

Is it a case of super gluing the shaft to the plastic bearing then?  This one seems to function at first, but works loose shortly after operation. 

 

Yes. I think its a design flaw that all will suffer from especially if there's too much grease applied in that area.

 

I also roughened the shaft by rolling the side of a file along it. This is actually a better resistance fit but to be sure I added a small drop of superglue. 

 

Hopefully that works

[Going2theDogs]

Hi All,

I have a couple if these Dapol class 121/122 & have been impressed with their running qualities

These are the Balfour Beatty version & the Hatton’s Ltd edition in original NSE livery.

Because of the positive experience I have had with these 2, I thought I would add a third to my fleet.

I purchased on 2 separate occasions (from 2 different supplies) within a fortnight this month. Both had to be returned due to lack of power on one of the bogies. It appears the drive axle had come loose & was just ‘floating’ where it should be ‘engaged’.

Disappointing & I am now a little cautious to try for a third time.

[JohnR]

8 hours ago, CB Rail said:

Hi All,

I have a couple if these Dapol class 121/122 & have been impressed with their running qualities

These are the Balfour Beatty version & the Hatton’s Ltd edition in original NSE livery.

Because of the positive experience I have had with these 2, I thought I would add a third to my fleet.

I purchased on 2 separate occasions (from 2 different supplies) within a fortnight this month. Both had to be returned due to lack of power on one of the bogies. It appears the drive axle had come loose & was just ‘floating’ where it should be ‘engaged’.

Disappointing & I am now a little cautious to try for a third time.

 

Yes, I if was looking for a 121, I would probably go for the Bachmann model, but no alternative for a 122. 

[GD]

10 hours ago, CB Rail said:

Hi All,

I have a couple if these Dapol class 121/122 & have been impressed with their running qualities

These are the Balfour Beatty version & the Hatton’s Ltd edition in original NSE livery.

Because of the positive experience I have had with these 2, I thought I would add a third to my fleet.

I purchased on 2 separate occasions (from 2 different supplies) within a fortnight this month. Both had to be returned due to lack of power on one of the bogies. It appears the drive axle had come loose & was just ‘floating’ where it should be ‘engaged’.

Disappointing & I am now a little cautious to try for a third time.

Hi, I also recently purchased a 122 and it was a terrible runner, stuttering then surging and making a strange noise, it was returned the next day.  

[ColinK]

I tried to run mine for the first time in three years a couple of weeks ago.  It was a superb runner before, but now has exactly the same problems, one bogie runs as it should, the wheels on the other no longer go round.

 

I really want to fix it as I renumbered, detailed and weathered it.

[Tony Cane]

As recounted earlier in this thread, the best fix is the replacement of the drive shafts. These are available as spares on the DCC Supplies site and my impresion, having done one such replacement, is the the design has changed to reduce the stress on the small plastic part at each end. clipping the drive shaft in to the bogie end requires the use of fine nose pliers, and more force than I was expecting to use. There is a "necking" at one end of the shaft that aids the final fitting.

[dj_crisp]

I'm kinda expecting every Dapol 121/122 to eventually have the spinning problem.

 

Replacement drive shafts or burring the existing drive shaft and superglue the knuckle on will help sort this. I think this part of the design is the weak link due to a really powerful motor, slightly stiff gears and the close proximity of grease.

 

It's not a difficult fix but still a bit of a pain.

 

23 hours ago, JohnR said:

 

Yes, I if was looking for a 121, I would probably go for the Bachmann model, but no alternative for a 122. 

 

For my 122s I've used a Dapol body on a Bachmann Chassis. A bit of hacking to the 122 body is needed but other than that it turned out OK.

[Ernie527]

I have two of these models. Both have suffered the same transmission problems. The carden shaft is made of steel whilst the two transmission lugs on the shafts are plastic. I found that these were spinning around the shaft and therefore not transmitting power. My solution to this was to rough-up both ends of the shaft and superglue the plastic lugs. I also took out one end of the gears & removed the  carden shaft. Its a bit fiddly, and I had to cut two wires to get to the bogie, then re-solder the wires in place...but its been worth it. Both run perfectly; faster and slower when needed. I feel that there is less snatching & undue torque with more control on the motor now... but you need time and patience to do it. Dapol would do well to change their design and replace the carden shaft with a solid plastic type, like Bachmanns, and to re-gear to a single bogie on the Bubblecar.

 

[ColinK]

On 01/09/2022 at 11:03, ColinK said:

I tried to run mine for the first time in three years a couple of weeks ago.  It was a superb runner before, but now has exactly the same problems, one bogie runs as it should, the wheels on the other no longer go round.

 

I really want to fix it as I renumbered, detailed and weathered it.

I sent mine to DCC Supplies to have it repaired. It should be back very soon.

[andyman7]

Having read this thread I thought I'd better get my 122 out too, that had been running fined when put away a couple of years back but....now motor just turns with no drive. I've stripped it down although one of the plastic driveshaft ends disappeared entirely in the process. The ones that had come off were split, only one of the four was in place and secure. I concur with other observations above, that a combination of motor torque and the resistance through the bogie worm drive chain exceeds the load capability of the driveshaft as designed. I'm also not a fan of the greasing of the gears, which inhibits free running.

I shall contact DCC Supplies to obtain replacement driveshafts. But for this one (admittedly critical) failure point it is a lovely model.