Bachmann 08 to P4

[Rustyrail]

Hello all (after a long time away)!

I thought you might like to hear about my ongoing Bachmann 08 conversion. This is the first RTR loco that I've converted to P4 and my experiences have been reasonably favourable - so far. The starting point was an already heavily modified Bachmann 08 in BR blue livery which used to run on one of my OO layouts. My model was one of the first batch of Bachmann shunters that had the less pronounced leaf spring detail (but with the coupling rod joints in the right places). Around the same time that I purchased the loco, Tim Shackleton wrote an excellent follow on article in the MRJ (No.124, 2001) about upgrading the Bachmann model. After reading this thoroughly I decided to follow suit and upgrade the leaf springs and add separate spring support rods to my 08 - in more or less the same way as Tim. This conversion is definitely not for the faint hearted! It is time consuming and very difficult to execute, to avoid inadvertently removing (with a fine scalpel, in my case) fine detail on the outside frames. Half way through the process I began to wish I hadn't started, but continued all the same. Once the appropriate extraneous moulded detail had been removed, I started to make up new leaf springs from individual layers of fine brass strip and thin pieces of plastic card. The rods themselves were fashioned from very fine brass rod/wire. The results, once painted and weathered were, quite simply, fantastic, totally lifting the visual appeal of the loco... from any angle. Suddenly it resembled a real 08 and had a more powerful look about it. To my mind, if you're going to invest time and money converting this already excellent model to P4, then why just stop at replacing the wheel sets? Surely it is worth going the extra mile and getting a more prototypical machine? To my eyes, the lack of separate spring support rods on 4mm 08 shunters really spoils otherwise lovely and characterful models. It really is worth the time and effort doing. Now I'm at the stage of converting the model to P4. The Ultrascale conversion is pretty straight forward if you take your time, however, the hardest part to get right is carefully bending the phosphor bronze pick ups to the wider gauge. I wasn't able to remove the motor block from the outside frame assembly so was forced to bend the pick ups in situ with limited room to manipulate fine nosed pliers. Anyway, the loco ran first time (once I'd temporarily replaced the coupling rods) on my P4 test track, albeit a little noisily, due to adjustments needed on the pick ups. I am now adding plastic card balance weights to the wheels (not easy) and super glueing them from behind, whilst held in place by a small bit of blutack. I will then paint and weather the wheels and repair some home grown fine chassis details that got damaged during the wheel conversion. I can't decide whether to keep the loco in rail blue or replace the body for an early BR black one that I have (both liveries are nice). The loco is destined for my layout "St. Mary Hoo". I will post some photos of my 08 efforts shortly! Thanks for reading!

Cheers
Simon

[grovenor-2685]

however, the hardest part to get right is carefully bending the phosphor bronze pick ups to the wider gauge. I wasn't able to remove the motor block from the outside frame assembly so was forced to bend the pick ups in situ with limited room to manipulate fine nosed pliers.

I found it possible to twist the pick ups through 90 degrees, more or less so they engage on the edge of the flange rather than on the treads or the flange back. They have been very reliable now for several years.
Regards
Keith

[Rustyrail]

Hello Keith,

Your suggestion is indeed a possibility and obviously a reliable one. However, by employing a similar method to Bachmann there is even a slight amount of spring on all wheels, in addition to the centre sprung axles which will help keep as many wheels as possible in contact with the rail surface.

I forgot to mention the excellent Brassmasters coupling rods and balance weights that are available for this model. I chose to refine the Bachmann rods as much as possible (using a needle file) and fabricate my own balance weights.

Cheers
Simon

[Flymo748]

Hello all (after a long time away)!

I thought you might like to hear about my ongoing Bachmann 08 conversion. .... The loco is destined for my layout "St. Mary Hoo". I will post some photos of my 08 efforts shortly! Thanks for reading!

Hi Simon,

Thanks for telling the story! That sounds really intriguing about the improvements that you've gained.

Anyway, to the question I have - didn't you start a blog/thread somewhere about St Mary Hoo?

My fading memory recalls that it was going to be a Dungeness-esque CEGB power station thing, set in the wilds of Essex, or Norfolk or some such eastern fastness... Have I lost the plot entirely, as well as the bookmark to your scribblngs?

Flymo

[Rustyrail]

Hello Flymo!

No you haven't lost the plot, and you are spot on (location/subject wise). I started a blog about the layout but various unforeseen circumstances got in the way so it remains in mid air so to speak. The blog can be found here: http://stmaryhoo.blogspot.com/

I certainly intend carrying on with project and the 08 is a sort of reintroduction to it...

Cheers
Simon

PS - Keith I don't suppose you have some photos of your 08 pick up arrangement?

[Flymo748]

No you haven't lost the plot, and you are spot on (location/subject wise). I started a blog about the layout but various unforeseen circumstances got in the way so it remains in mid air so to speak. The blog can be found here: http://stmaryhoo.blogspot.com/

Hi Simon,

Glad to know that I hadn't made it a complete figment of my imagination!

A quick whizz over there shows that I'm already subscribed as a Follower, so I'll look forward to future updates

Flymo

[Re6/6]

This method of additional pick-up has served me well for some years. It was shown to me by Tim Maddocks from his 'workbench' on one of the old incarnations of RMweb. Simply small strips of copperclad are epoxied on, with phosphor bronze strips soldered to them. Thus by retaining the originals each wheel has two pick-ups. Simples!

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[Rustyrail]

Many thanks for your post and the excellent photo Re 6/6! I've now tweaked the pick ups in the same way that Keith suggested, bending them by 90 degrees so that they touch the back of the wheels and this seems to work a treat; the noisiness has now stopped and it performs like it did in its stock OO Bachman guise, i.e. nice and smooth. One thing I've noticed, however, is a distinct type of lumpiness in the running (one direction only). Whether this was there before the P4 conversion I can't remember, as it is so long ago that I used the model. It's not too alarming and doesn't affect its progress through curves, etc, but it is annoying. What could be causing this is a mystery; I've checked for any obstructions to the wheels, cranks, etc but nothing shows up. There is nothing on the wheel treads and the quartering is spot on. My only theory is that it is a gearing problem, with one of the nylon gears not running concentrically, which might cause a slight movement downwards on the driving wheel brass gear. Has anyone else noticed this after converting the Bachmann model with the Ultrascale wheel set?

[martin goodall]

One thing I've noticed, however, is a distinct type of lumpiness in the running (one direction only). Has anyone else noticed this after converting the Bachmann model with the Ultrascale wheel set?

You should suspect the centring of the coupling rods compared with the wheel centres.

There have also been issues in some cases with the accuracy with which the axle slots are machined in the chassis block. So you might also check this.

Re-centring the crank-pin holes in the coupling rods may well be the answer to the problem.

This, or similar problems, have been reported on this forum several times in the past. The same problem seems to afflict the Bachmann 45XX.

[Rustyrail]

Cheers for the info Martin. I'll have a look at those things. If it was the coupling rods wouldn't it show up in both directions?

[Rustyrail]

A photo showing the general 08 devastation during the P4 conversion yesterday. More photos to follow!

[Wizard of the Moor]

One thing I've noticed, however, is a distinct type of lumpiness in the running (one direction only). Whether this was there before the P4 conversion I can't remember, as it is so long ago that I used the model. It's not too alarming and doesn't affect its progress through curves, etc, but it is annoying. What could be causing this is a mystery; I've checked for any obstructions to the wheels, cranks, etc but nothing shows up.

I have observed a similar problem with my Bachman 08. I suspect it is due to the slop in the knuckle joint of the rods. The joint will hit the Ultrascale crankpin washer when running in the right direction.

FWIW, I have just converted a Hornby 08 using the Ultrascale wheelset. This is bit more involved than the Bachmann conversion!

However, when I tried running it in the performance was horrendous. It was as if one wheel would throw itself off the track each revolution.

The Hornby rods are much better than the Bachmann ones, although my pair were twisted over their length. Removing the twist helped.

I then changed the Ultrascale 14BA washers to 16BA ones with the holes broached out to fit the crankpins. The running was then much improved. After about 6 hours on the rolling road it now performs adequately. I suspect that similar mods to the pickups as Re6/6 shows above will be needed to get things better.

[Rustyrail]

Very interesting James. I have a Hornby 08 in OO and having had a look under the keeper plate (to solve a mysterious running problem) I can only concur with your observations; i.e. the conversion to P4 would be a more complex process than the user friendly Bachmann model, mainly due to the tightly fitting hornblocks. My Hornby 08 (a very nice looking model) used to be extremely smooth with incredible flywheel movement - after the power was switched off - where it would run on for several centimetres. But recently it has developed an erratic attitude; it will proceed nice and slowly and then suddenly blast into TGV mode for no apparent reason, then return to a more sedate 08 style! I've investigated every possible cause from transformer, dirt on track, dirt on pick ups, gears, etc, etc. I am now wondering if the motor itself is faulty. Not only that but the gears have developed an unpleasant high pitched screech at higher speeds (a friend of mine has the same problem with his Hornby 08). The trusty old Bachmann model on the other hand (now successfully converted to P4) is incredibly reliable and robust, and it's ten years old now. I will post some photos of the finished model in due course. It is resplendent in BR black livery and looks very nice with its new wheels, etc.

Cheers
Simon

[JerryO]

I too had a number of problems when converting my Bachmann 08 to P4.

I used the Ultrascale conversion wheelset with Brassmasters Coupling rods.

I had pronounced click in one direction which was eventually traced to the fact that one of the re-formed pick-ups was digging into wheel due to the fact that the contact face did not have lead-in in both directions. This was lifting the wheel before being released.

Another problem which should also be noted is that the add-on balance weights need to be positioned to they are flush or underflush with the tyre rim otherwise they will catch on the plastic brake rods and further dressing with file ensures any edges are smoothed.

[craig_whilding]

Buying replacement Brassmasters rods will eradicate much of the problems possible in the conversion of an 08 from either company.

Although the Bachmann is the quicker conversion the Hornby model has axleboxes and hornguides and can be properly sprung as well as being better engineered to begin with. A shortcut is just to spring the middle axle with some handrail knobs and wire giving a similar effect to the Bachmann as bought but its better to spring the lot.

[Rustyrail]

Here's the 08 with the more or less completed chassis (P4 Ultrascale driving wheels; home made balance weights, etc). The BR black livery is very attractive and not as common as the usual blue and green examples one sees on layouts. Although it is hard to see from this angle, the scratch built metal leaf springs have separately applied support rods. Several added details are incorrectly painted for an 08 of this vintage as the chassis came from a BR blue example. The black body still needs attention; subtle weathering, added details and what not. The coupling rods are not as fine as I'd like and I may reduce these still further. The loco runs very smoothly now.

Cheers
Simon

[Rustyrail]

The unsuspecting Bachmann 08 straight out of the box before being converted to P4 (just for comparison purposes).

[Rustyrail]

A photo showing the model in its BR blue guise since conversion to P4...

[JerryO]

The pictures show up a quirk I have noticed with the two body types.
With the body type that has long hinges straps, the upper locking strap on the rearmost full side access panel is above the line of the adjacent handrails whereas on the body type with short (low profile) hinges it is below the line of handrails. This occurs is on both sides.
I have studied prototype pictures and have not found this difference.