Bachmann E4

[nberrington]

Has anyone had a go at converting this loco yet?

[Philip Hall]

I have one to do quite soon, although to EM, but I know of two amongst friends which are going to be in P4.

As far as I can make out it's pretty simple (although I have yet to actually take it apart) but it probably will need dummy frames to remove the gap behind the wheels. Apart from that it must be a good starter as it runs wonderfully straight out of the box. The one I have been asked to do in EM will not get the dummy frames as the new owner doesn't require them. Alan Gibson does the correct wheel now with 3mm axles.

Philip

[dal-t]

it runs wonderfully straight out of the box.

But there have been quite a few reports of unconverted examples persistently derailing when running bunker-first. Several You-Tube videos seem to show pretty jerky forward motion too, but that may just be down to poor filming (amazing the number of people who think you can forget all the principles of good photography as soon as you pick up a movie camera). I don't know if simple conversion will solve any road-holding problems, but at least in P4, unlike OO, there should be a proper relationship between track and wheel standards. Whether the reported difficulties are caused by poor quality control or inherent design fault is unclear, but it might be worth considering a form of springing/centering for the trailing axle while the chassis is apart.

[Philip Hall]

I've had a quick look at the one I have here and the rear axle runs in a radial slot, but only relies on the weight of the wheelset to keep it on the track, so that could well be a cause of the wheels jumping off the track. I will try to incorporate some downward springing once I have the chassis apart, although I doubt I will bother with side control, as it is to be in EM and capable of traversing a 2'6" radius curve. The chassis is unsprung, of course, but seems perfectly square, and with concentric wheelsets I am quite confident there will be no running problems in either EM or P4.

I haven't seen the YouTube videos, but a lot of those videos I have seen have been jerky. My example simply glides along (many builders would envy the running quality) and friends who have them tell me the same story. I am really looking forward to the job, something I cannot always say with some of these conversions!

Philip

[Terry Bendall]

Back in MRJ no. 19 Barry Luck described his loco construction methods which included a radial axle box for the E4 made from a section of acrylic. In Scalefour News 160, part 5 of my series on using machine tools described how to make one. Since I have one of the Bachmann E4 waiting to be converted I shall use this method of making an radial axlebox and as Philip says put a bit of springing on it.

For those with the equipment and the skill, making a radial axlebox to Barry's ideas is not that difficult but for those who do not have one or both of these things, come and see my demonstration at Scalefour North and you may find some being made.

Terry Bendall

[Will L]

Back in MRJ no. 19 Barry Luck described his loco construction methods which included a radial axle box for the E4 made from a section of acrylic. In Scalefour News 160, part 5 of my series on using machine tools described how to make one. Since I have one of the Bachmann E4 waiting to be converted I shall use this method of making an radial axlebox and as Philip says put a bit of springing on it.

For those with the equipment and the skill, making a radial axlebox to Barry's ideas is not that difficult but for those who do not have one or both of these things, come and see my demonstration at Scalefour North and you may find some being made.

Or London Road Models do an etch, I haven't actually used one yet but I have enough (two) for my Gibson F6 kit (2-4-2), and they look like they ought to be OK.

[Knuckles]

Well, I've brought a brand new Bachman E4 in LBSC brown livery from Hattons for £80, is an absolute corker visually and the chassis is metal. The whole loco weighs a bomb and has that 'quality' feel you get with weight. Runs well on my 00 track so looking forward to converting this to P4 although I'm unsure when as I'm tied up with a bunch of things.

Scared of making a pigs ear out of it - Not really sure how to transfer the gubbins on the axles to replacements, really don't want to bugger it up but we'll see how it goes eh?

[Philip Hall]

The EM conversion was almost a doddle and ran like a watch. The driven axle is as simple as Bachmann engines often are - just mark the position of the gear on the 00 axle and transfer it to the P4 or EM one. I knurled the axle with a file but the gear is a stiff fit so all should be well even without the knurling. I did put a pin through the boss into the axle but that's just me being careful.

In view of previous comments, there is so much slop in the trailing axle (the slot is far too big for the axle) and the truck is far too narrow, therefore it flaps around all over the place, probably the reason for all those derailments. I took all the slop up with a tube over the axle, but a plain 2mm axle is almost as good. The Bachmann axle is below 2mm, I can't remember the exact size. This stops it waving around so much, and I also added lots of washers to remove virtually all of the sideplay. There is actually a downward spring on the axle which need a little shortening so it doesn't foul the truck frame - you have to deepen the axle slot as the replacement wheels are the correct size, rather than the Bachmann originals which are too small.

Although it's EM I can post a picture later if anyone is interested (?) along with the adjustments to the trailing truck. I have prepared wheelsets for three P4 ones as well for others to convert.

Philip

[Knuckles]

Sounds good to me, the info, pics and wheelsets.

When I converted the 5700 with Ultrascale 'droppins' (sounds wrong!) it was an easy conversion that still runs well but I never bothered to thicken the frames so it looks like you could quite literally squeeze a baby elephant in there.

Would like to maybe try Keith's lead frame thickeners this time although the engine is so heavy to begin with styrene may be perfectly acceptable.

It looks like the brake pads will need clipping off and repositioning entirely and the pick up. wipers I'm hoping will pull out ok as they did on the pannier.

A bit nerve racking really. At least the wheels are plain black though, no lining to replicate.

[Philip Hall]

Here as promised are pictures of the EM conversion, P4 would be exactly the same apart from more spacing washers. Pictures show the trailing truck with the tube over it to remove the slop in the bearing slot - actually the axle is too thin and I didn't realise this at the time, so a 2mm axle will take up all this play. The slot needs deepening to account for the correct size wheels, and the spring melted onto the truck moulding will need shortening at its outer end to allow the axle to go to the top of the deepened slot. When you look at an unaltered one all will be clear.

On this one I checked the rods matched the chassis (I think they did this time) but I reduced the size of the bosses and slimmed the rods down a bit after bushing - the Bachmann ones are far too chunky. Upper rod is as supplied, lower one reduced. My method of setting the sideplay is also shown - I have a wooden axle which is a sliding fit in the wheels and I add or subtract washers (in this case 6BA nuts - some filed down a bit - and Peco fibre washers) until I'm happy. This lot can then go on the axle before it all gets assembled in the GW press and should be about right to go in the chassis when all is done. For instructions on mounting wheels, Mike Ainsworth's advice in the latest Scalefour News is very sound, as was Chris Pendlenton's in MRJ a while back. I did file a little bit off the top of the middle axle bearing to allow a tiny bit of upward movement. Sometimes you get this anyway on a RTR chassis but this one is flat and true, and a little movement with a rigid chassis is useful. Only a tiny amount is needed, enough to get a piece of cigarette paper under the wheel when the chassis is on some plate glass.

You might notice that this one didn't have the frames widened as the customer didn't require it, and I am increasingly finding myself considering whether on many engines it actually does show when you're viewing from two feet away, particularly on engines where there is a lot of gubbins like sandboxes and brake gear between the wheels or the wheels are very close together. The brakes are spaced out by my usual method of carefully squeezing the mounting brackets on the keeper plate to move the brake hangers out a bit so they line up with the wheels, and I do the same with the brake rodding moulding. There are more elegant methods should you care to drill holes in the chassis and remount the hangers, but this is a lot quicker, if a trifle risky. Yes, I have had brake hangers ping off into the carpet. Once it's cleaned up and painted you'll never see the difference.

Hope this is useful.

Philip

E4 EM 1.jpg

E4 EM 2.jpg

E4 EM 3.jpg

E4 EM 4.jpg

E4 EM 5.jpg

[nberrington]

Thanks Phillip! It's a gorgeous engine, and I feel less intimidated by the idea of converting it....