A view of/on RTR conversions to EM/P4 - part 1
Entry posted by drduncan in RTR to EM/P4
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This is Mikkel's fault (something that Gareth of fond memory and posts past will be extremely grateful). Mikkel kindly commented that he had found one of my blog posts useful for visualizing the work required for EM/P4 RTR conversions. Unfortunately, the all too brief skirting over a great deal of faffing around with that particular conversion may give a false impression of the work - or thought - required.
The theoretical basic flow is something like this:
- Invert victim in a suitable cradle (I use a PECO loco servicing cradle made from foam)
- Remove nut/bolt/pin securing the connecting rod to the driven axle (if victim has outside cylinders)
- Remove keeper plate (save screws in suitable container).
- Remove driving wheels.
- Remove coupling rods from wheels and remove carefully gear wheel from driven axle.
- Remove any pony/bogie/tender wheels.
There - very simple. Now just put it back together...
- Assemble chosen tender wheels and fit
- Assemble pony/bogie wheels and fit
- Knurl the driven axle and fit the gear wheel
- Assemble and fit the driving wheels
- Fit coupling rods
- Fit connecting rod
- Refit Walscherts kitting (if used)
- Test
- Bask in the glory of your achievement.
There. Extremely simple. Only practice can be very different...
The actual flow:
- THINK about what you are about to do and the order that your think you need to do it! Research; has anyone else done this before and what do they say about it? Are there guides? - Alan Gibson (AG) does some on his website using his products (obv) but the EMGS has their own manual sheets too (and is one of many reasons for joining this society even if you aren't EM but are more interested in a finer approach...) I'm not an S4 member so can't comment on what they supply but I can't imagine that they don't have similar advice sheets. Read such guides/instructions carefully - do not assume they will be correct. I know of at least one set where it looks like earlier components (in the instructions) had not been fitted at later points in the build photos...and yes it made a difference. So do think critically about what you are being told/suggested to do!
- ORDER the necessary components/tools.
Some of the bits ordered to convert a Bachmann Ivatt/Standard class 2 2-6-0 to P4. Note AG colours the P4 bits blue compared to yellow for OO/EM/general parts....
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Wheels:
- Make sure you have 3mm axles not 1/8 inch ones! You effectively have 3 choices: Markits/Romford (££); Alan Gibson (£); Ultrascale (£££). [I know Sharman wheels are now available but I don't know if they can be supplied for 3mm axles]. Markits are pricey compared to AG but are self quartering (which AG aren't); Ultrascale can supply pre-assembled but you wait about 6 months and they aren't cheap (but are extremely high quality). The EMGS do EM and P4 AG conversion kits; these normally are just the driving wheels and crankpins needed
- Make sure you get the correct profile - EM wheels aren't the same as P4 ones (although according to an article in a past MRJ (so it cannot be untrue)...no let's not go there again; certain P4 practitioners might just have a stroke if I bring that topic up again)
- Spacing washers - 2mm and 1/8 in a variety of thicknesses 1mm/0.5mm/0.25mm. Buy more than you think you'll need; RTR chassis are very narrow! You'll only need about 0.5-1mm of side play (and in P4 you may need much less behind slide bars and piston crossheads)
- Do you want to use cosmetic sideframes? Ultrascale do some...
- Crankpins to suit the wheel. Ultrascale do a variety to suit the amount of space ie special thin ones for tight spots behind those pesky slidebars.
- Valve gear rivets if doing anything with outside valve gear
- AG coupling rod bushes or do you want to use some of the replacement rod sets made by people like Lancashire Model Supplies that are designed for specific RTR models?
- If doing Walschaerts outside valve gear (first why????) you'll also need a pair of eccentric cranks - AG and Markits do them and they are not (to my knowledge) interchangeable ie if you're using AG crankpins you'll need an AG eccentric crank and vice versa.
- Tools 1: if using Markits have you got one of their axle nut spanners? If not get one - its worth the hassle saved. If AG/Ultrascale do you want to get a quartering jig/wheel press? (Yes you do...)
- Driving wheel balance weights? Make your own from 5 thou plasticard, use Ultrascale laser cut ones, or Markits etched ones? Or from another source?
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Tools 2: You will need:
- Some sort of loco cradle (mine is from Peco)
- Flat and round needle files
- Pliers
- Side cutters
- Permanent marker pen
- Soldering iron, solder, flux (non corrosive please)
- Scalpel/craft knife
- 6" or longer bastard file.
- EM or P4 back to back gauge to taste.
- You may need:
- Cutting broaches (definitely if using AG Walschaerts eccentric crank)
- 1mm tap (as above)
- 0.7mm drill and pin vice
- Parallel pliers
- Empty clutch pencil
- hand vice
- small vice with smooth jaws.
- A Micro Rail 'truck tuner'
- A brass bearing tool:
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Some things to ponder or try not to forget to do as you invalidate the manufacturers warranty by taking the beastie to pieces:
- Body on or off? Body on is sometimes faster but any outside gubbins will get in the way and slow you down. Better to take the body off so you can unscrew cylinder blocks and motion brackets (especially with Walschaerts valve gear) to decrease the chance of snapping anything like a connecting rod where it is stamped into a crosshead (been there, done that). Keeping the body on does decrease the number of screws you can lose...
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- A Bachmamn L & Y Radial tank being converted to P4 for the Gosport Guru (who had me do three in a row). This lacked any outside gubbins at all so was easy to do with the body on...
- What about all the bits? Plastic boxes and bags are your friends and something to put there and the body, chassis etc in will also help too. I use carefully cleaned (in the dishwasher) Chinese takeawy boxes...
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- A Hornby J15 disassembled (well nearly) ready for conversion to EM.
- Beware keeper plate wiring between pickups and motor. Hornby and Bachmann seem to favour using spit as solder and gossamer thin wires that snap as soon as you look at them. Although breaking the soldered connection may require fiddley soldering to put right, replacing the dodgy wires with something better can allow you to do outrageous that manufacturers seem to think aren't necessary on all models - like tender pick ups, dcc sockets and moving the dcc socket into the tender where it can be accessed without going near any painfully reassembled (and temperamental bits) on the loco proper.
- You'll need to get the wheels off the axles to recover the gear wheel and any axle bearings (not that these are always deemed necessary by some manufacturers). Do not twist the gear wheel - its on a knurled axle to you'll damage it if you do. Direct downward pressure to shift it only (I use pliers)...
- Using pliers to spread apart the wheels from a Hornby Claud Hamilton (EM conversion) to recover the axle bearings.
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With everything nicely reduced to components you can start putting it back together.
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If your pride (and possibly still at this stage, joy) has a tender start your surgery with that.
- Some RTR tenders are designed for inside bearings (like the Claud Hamilton tender below), some rely on outside bearings like the Stainier mogul even further below. Inside bearing use blunt axles, ouside bearing ones will normally need pin point ones.
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- The Hornby Claude Hamilton tender showing (amongst other things) the plastic inside bearing that the axles push fit into.
- You may need to remove some material either from the inside face of the frames or around any slots in the tender floor for the wheels to get the wider EM/P4 wheels to fit and turn freely.
- For an outside bearing tender it is almost certainly worth giving the plastic pin point bearing surfaces a tune with the Micro Mark (or similar) 'Truck Tuner'.
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- The tender from a Stanier mogul being treated to a 'Trick Tune' to ream out plastic outside bearings. You can also see where material has been removed from the inside face of the frame to get the wheels to fit.
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If your pride (and possibly still at this stage, joy) has a tender start your surgery with that.
In the next part (cos I'm sure you're bored now and I want to moan about the Bachmann Standard 4 Mogul elsewhere) I'll talk about the practicalities of getting the new wheels installed, mostly concentrating on the Alan Gibson offerings.
All the best and stay safe.
Duncan
Edited by drduncan
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