Dapol Class 121 disassembly

[Vanders]

When Dapol first released the Class 121 it seems the BR Blue versions were wildly popular, and I missed out on one. As my layout is crying out for a blue 121, I had a cunning plan: buy a cheap NSE powered version, a discounted blue un-powered version, and swap the bodies over! Simple, right?

 

I've seen lots of people asking how to do it, but so far no one who's actually done it. So, here's my simple step-by-step process of how I dismantled a Dapol Class 121 (actually, two of them!)

 

The first thing to do is remove the roof (simple, it's designed to just pop off), remove the lighbar (if fitted), the DCC decoder/blanking plug and optionally, pull out both bogies. Note that once you go past this point you're firmly into invalidating your warranty, so beware!

 

Now remove the two screws which are holding the circuit board in. This is simple but use the correct size screwdriver or you will strip the screws very easily.

 

 

Put the screws safely to one side, and then remove the two screws which are holding the seating in. One is located below the circuit board: be very careful when you move this board of out of way as the thin wires may break easily.

 

 

Now start to push out the sides of the body gently: I placed both thumbs on the inside and flex the body out. There are several clips all along the bottom of the body that clip onto the chassis: as you flex the body, try to gently pull the chassis down a little bit. Eventually you should find that a gap begins to form between the chassis and the body. I found it easiest to do this along one side first but your mileage may vary. Note that there are a series of cross-members between both sides of the chassis, so if you push too hard you may snap these (I snapped one on the first unit I tried: thankfully it was a clean break. A little super glue soon fixed it).

 

Eventually, you should be able to separate the body from the chassis and lift the body & seating unit up. Don't try to pull the body clean off: the circuit board is still "trapped" between the seating & the chassis!

 

 

Now it's quite and easy process to push the seating unit up from below: flex the body sides against slightly so that the seat moulding clears the various clips & bumps on the glazing. Note that the powered units have a cast metal seating unit, while the un-powered units have a plastic one! The plastic unit is easier to remove, although the metal one isn't much more difficult.

 

 

Once you've got it apart of course, you probably want to put it back together again. This proved to be more difficult than taking them apart in the first place! A few notes:

 

1. There are two different types of LED circuit board on the chassis: one for newer prototypes with the centre high-intensity headlight and one for older prototypes without. As I was putting an older body on a newer chassis this wasn't an issue for me (I just have an extra LED you can't see), but obviously if you put a newer body on an older chassis you'll lack the centre headlight.

2. Getting the LED boards in place at the front of the chassis proved to be very difficult when I re-attached the body to the chassis. In fact I thought at first I had damaged one of them in the struggle, but in fact the circuit board was still out of place. I did manage to gently push it back into place again from underneath, luckily.

3. The fragility of the exhausts is well known already, so be careful. I also managed to sheer off a buffer, although it was a clean break and a spot of superglue soon solved it.

4. Once the body is off, the chassis is actually quite flexible thanks to the use of plastic carden shafts. I found it easier to flex the chassis away from the body and "slide" both ends into the body, then push the chassis onto the body until it was all clipped into place.

5. It's easier to fit the body to the chassis first and then push the seating unit back into place. Be careful not to trap or damage any of the wires from the chassis to the circuit board when you're replacing the seats.

 

Hopefully this might be of some help to people who are contemplating a body swap: it is possible!

[markwilson]

Hi, I don't suppose you still have the unpowered NSE one for sale do you?  I've just bodged a repair on my powered NSE one, got glue on the windscreen, isopropyl alcohol on my fingers, smudged the transfers, and now looking for a cheap NSE body to put the smile back on my 10yo's face :-(

 

(it's either that or a trip to a paint shop for some very heavy weathering to cover up my mess...)

[markwilson]

I just wanted to say thank you for posting this - it gave me the confidence to swap bodies over. I picked up a Network Rail class 122 body on eBay and put that on the 121 chassis.  Had a bit of difficulty getting the body off (had to be a bit rougher than I would like, then it suddenly came off); similarly struggled a bit re-inserting the seating plate (due to the various "lugs" on the glazing - and as you commented in your article) but it's in, and working.  And I now have a relatively rare model of a Network Rail 122.

 

Biggest problem with these models is the flimsiness of the exhausts on the guard end. The 122 is slightly better than the 121 as it's not the "cow bar" shape but it's still not fantastic and will need a lot of care when putting into storage/taking out again (mine won't be stored in my usual foam trays any more)...

[Vanders]

No problem at all! The 121/122's seem to be one of the more difficult models to deal with, and at the same time livery variations seem to be slow to appear from Dapol; 121's seem to be almost non-existent at the moment! Hopefully my experience has been useful to others who want a particular livery combination that Dapol hasn't issued yet.