Bachmann 46 to P4 using Ultrascale conversion

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ClikC
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Mon Jul 16, 2012 5:29 pm

Russ Elliott wrote:Am I right in thinking that the principle of the original Bachmann 1-B-1 sprung bogie is like this?

1-B-1-bogie.png

If so, the position of the point at which the body impinges onto the bogie is important, and will determine the track-holding of the axles. I think I would be inclined to sort the rear axle spring strength first, i.e. get the bogies running reliably without their front carrying ponies, and only then put enough strength on the pony spring sufficient for its track holding.

Justin's point about ensuring sufficient sideplay is also very pertinent.


In answer to Russ's qestion: Centerally over the two driven axels (Hence the bogies one the 40's and 44/45/46 pivot in an unprototypical position) attacked to the chassis at the top of the bogie tower.

The spring is for the pony wheels is almost neglegable straight out of the box. I normally remove the pony, give the strip of metal that acts as the spring a tweak, then add a strip of lead to the pony, and reattach ensuring the screw is not overly torked, to provide free play and allow gravity to take most of the work.

Also worth noting that you don't want the screw holding the bogie tower to the chassis overly tight, or your'll make the whole unit too tight and significatnly reduce road handling.

Regards

Matt
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Russ Elliott
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Russ Elliott » Mon Jul 16, 2012 5:30 pm

Is the rear axle a saddle spring and the pony truck a cantilever leaf spring?

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby jim s-w » Mon Jul 16, 2012 5:31 pm

Hi russ

In terms of the springing both versions are the same. The unprototypical pivot is a pain if you want to fit lifting brackets.

It will be interesting to see if the new class 40 has a different bogie design.

Cheers

Jim

Ps in answer to your last question, yes
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Russ Elliott » Mon Jul 16, 2012 5:51 pm

jim s-w wrote:In terms of the springing both versions are the same.

As a point for my clarification, Jim, do you mean both the old 1-B-1 version and the new 1-Co version? (I'm not up to speed with the latest Bachmann shenanigans.)

ClikC wrote:Also worth noting that you don't want the screw holding the bogie tower to the chassis overly tight, or your'll make the whole unit too tight and significatnly reduce road handling.

Ah, now we're getting somewhere. I really liked the way Bachmann got the roll freedom between the bogies of the Class 20 and 24 (sort of rolling the bogie about the drive tower worm axis), but I'm not familiar with the 45/46. Does this 'screw holding the bogie tower to the chassis' secure the mating of two flat surfaces?

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby jim s-w » Mon Jul 16, 2012 6:19 pm

That's right russ. Both have rigid inner axles and sprung outers on each bogie. The original design was like th mainline one with plastic sprung pony trucks. The newer design has a pony truck at the outer end sprung with folded brass and an axle in a slot at the inner end sprung by a coil spring and a metal boss.

As an aside to the bogie pivot being in the wrong place the pony truck pivot is too. Pony trucks on class 40 and 44-46 were pivoted from the front of the bogie not inside like a traditional steam loco.

Hth

Jim
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Mon Jul 16, 2012 6:20 pm

Russ Elliott wrote:
ClikC wrote:Also worth noting that you don't want the screw holding the bogie tower to the chassis overly tight, or your'll make the whole unit too tight and significatnly reduce road handling.

Ah, now we're getting somewhere. I really liked the way Bachmann got the roll freedom between the bogies of the Class 20 and 24 (sort of rolling the bogie about the drive tower worm axis), but I'm not familiar with the 45/46. Does this 'screw holding the bogie tower to the chassis' secure the mating of two flat surfaces?


Russ

It's IIRC Much the same as the 25 (just with extra wheels).There is a plate on the tower, and on the underside of the chassis block are two raised seams allowing the bogie to rock foward and backwards. I've often thought about removing this seam on one end of the loco, and replacing with some equally thick wire at 90 degree's, to obtain some crude compensation. But have always gotten away with just a wheel swap and a tweak or two. Which will do for the time being, until I can get arround to tackling springing one fully. But that'll be once the new Bachmann 40's land.

Regards

Matt
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Russ Elliott » Mon Jul 16, 2012 7:03 pm

ClikC wrote:It's IIRC Much the same as the 25 (just with extra wheels).

The wheelbase needing to be pitched is significantly greater though. Much will depend on the strength and consistency of that rear axle coil spring - damn pesky things are coil springs!

I've often thought about removing this seam on one end of the loco, and replacing with some equally thick wire at 90 degree's, to obtain some crude compensation.

That sounds like a very sensible no-cost work around, and would probably alleviate (to an extent) the lack of roll freedom between the bogies. I assume the seam straddles the fixing screw, but what is the length of the seam?

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Mon Jul 16, 2012 8:46 pm

Russ Elliott wrote:
ClikC wrote:It's IIRC Much the same as the 25 (just with extra wheels).

The wheelbase needing to be pitched is significantly greater though. Much will depend on the strength and consistency of that rear axle coil spring - damn pesky things are coil springs!

I've often thought about removing this seam on one end of the loco, and replacing with some equally thick wire at 90 degree's, to obtain some crude compensation.

That sounds like a very sensible no-cost work around, and would probably alleviate (to an extent) the lack of roll freedom between the bogies. I assume the seam straddles the fixing screw, but what is the length of the seam?


Russ.

They say a picture paints a thousand words, so I've taken some photo's of the chassis and bogie tower of my shelved center-split box Class 45 project, and an orginal release Bachmann Class 40 chassis block that I have laying about, awaiting the day I purchase a Milling Machine.

Image
Image
Image
Image
Image

The seam is .80mm width, 20mm in lenght and .80mm in height. The orginal release Class 40 seam is .80mm width, 20mm in lenght and 1.80mm in height. This was rectified on later releases due to complaints about the body riding too high over the bogies, and has now shed 1mm*.

The plate on the bogie tower is 11.73mm x 14.73mm with the widest section resting on the seam.

HTH

Regards

Matt

* Don't get me started on the errors pressent on either a Bachmann or Lima Class 40...
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Horsetan » Mon Jul 16, 2012 9:49 pm

ClikC wrote:.....* Don't get me started on the errors pressent on either a Bachmann or Lima Class 40...


Well, apparently, if you splice parts of both bodyshells together, you get a more-or-less accurate body. Or that's what they told me anyway......
That would be an ecumenical matter.

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby jjnewitt » Mon Jul 16, 2012 10:06 pm

Horsetan wrote:Well, apparently, if you splice parts of both bodyshells together, you get a more-or-less accurate body. Or that's what they told me anyway......


Bachmann cabs and the Lima middle with some fettling do make a nice looking model. Someone did one on RMweb though it might have been on the old site. It will be interesting to see if Bachmann make a better fist of their lastest foray into the world of Engilsh Electric type 4s.
Those drivetrains look odd in one peice. :)

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Horsetan » Mon Jul 16, 2012 10:32 pm

jjnewitt wrote:
Horsetan wrote:Well, apparently, if you splice parts of both bodyshells together, you get a more-or-less accurate body. Or that's what they told me anyway......


Bachmann cabs and the Lima middle with some fettling do make a nice looking model. Someone did one on RMweb though it might have been on the old site.....


Fortunately I did a hard copy printout before the whole lot was deleted. I still have cabs-plus-middle cobbled together; I'll get back to it someday.
That would be an ecumenical matter.

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Mon Jul 16, 2012 10:35 pm

Horsetan wrote:
ClikC wrote:.....* Don't get me started on the errors pressent on either a Bachmann or Lima Class 40...


Well, apparently, if you splice parts of both bodyshells together, you get a more-or-less accurate body. Or that's what they told me anyway......


Well if we're going there...

Image

All Lima. File back the Cab windscreens until the distance beteen the lip of the cab window front and the roof ventillator is 9.32mm (This allows room for the 2 layer Shawplan windscreen etch). You'll need to pack out the inside edge of the cab side window pillars with 40 thou plasticard, so you can file the correct angles to the cab windscreens. Then using a razorsaw make a cut at the angle of the cab windscreens down to just below the inside seam of the cab window fronts. Using a Razorsaw cut vertically behind the door frame, untill level with the underside of inside seam of the cabside windows. Using a Razorsaw start a cut horizonitally along the noseside below the inside seam of the cabside windows, then angle the saw upwards along the nose, do the same both sides. Then take a jonior hacksaw blade, and finish off those cuts. The body should now be in three peices (5 if you do both ends at the same time). Body, Nose bonnet, and nose front + nose sides. Pack out the vertical cut behind the door frame with a suitable amount of Plasticard (15 thou in the case of my razorsaw) and glue the nose back into position. Add a little 40 thou plasticard to the back of the bose bonnet, and glue that back into possition. Then you end up with whats in the picture, IMO the nose of a glass 40.

Basicly now I need too do the same the other end and draw file to remove .50mm from the bodysides. But in all honesty, I'm probably not going to bother. I'll just wait for the new Bachmann 40 to land. I've a small desire to do 40 009 circa 1974 because I started (and so I'll finish), but I either need to get another disc nose lima body. Or try to salavage parts from the other 3 lima bodies I sacraficed, in order to find working method of correcting the model. The bachmann body is even worse, to the point of being hopeless in correcting due to various moulded detail being out of possition. The lima body on the other hand has stuff, generally speaking, in the right place. But as I say, I doubt I'll bother, as I predict the Mk2 Bachmann Class 40 will be up to the standards of the recent Class 85.

Regards

Matt
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Russ Elliott » Tue Jul 17, 2012 1:00 am

Back on topic, which you might recall is John's 30-second "it's so easy" dropins turning out to be a head-scratchingly "not so easy" contemplation because it didn't work, I'm thinking that the roll freedom might be helped if that Bachmann seam is mushroomed a tad (its 20mm flat length is horrendous - I'm not surprised the darned thing doesn't stay on the track):

bach-tower-seam.png

Don't overdo it though, or you'll end up with a Hornby 'Pendoleanover'...

Edit: Getting at the seam will be a problem involving some nasty piercing-saw hacking of the casting sides, so maybe an alternative bodge is to grind the seam off and use a rubber washer (suitable O-ring??) around the fixing screw. Might provide that little bit of compliance for roll, and I don't think the pitch freedom would be overly impaired.
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Terry Bendall » Tue Jul 17, 2012 7:19 am

grovenor-2685 wrote:I don't see 40, 44, 45, 46 featuring on your list, but if you did not have problems with Bachmann 47s you were indeed lucky!


Things have moved on with this thread but just to repond to Keith's point, no we have not yet done any 40, 44, 45, 46s. That joy is yet to come, and all the 47s were Heljan not Bachmann.

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby jim s-w » Tue Jul 17, 2012 9:42 am

Russ Elliott wrote:Back on topic, which you might recall is John's 30-second "it's so easy" dropins turning out to be a head-scratchingly "not so easy" contemplation because it didn't work,


Hi Russ

Thing is, as several posters who actually have converted the Bachmann peak have pointed out, it should. I wonder if John has access to any other track to test the loco on as I am not convinced that the fault is with the loco. At the end of the day if I can make it work with my bodge it and see approach it must be easy!

Cheers

Jim
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Horsetan » Tue Jul 17, 2012 9:44 am

Terry Bendall wrote:.....no we have not yet done any 40, 44, 45, 46s. That joy is yet to come.....


To misquote Honda: "At Scalefour, we make.....joy."

ClikC wrote:.....the distance beteen the lip of the cab window front is 9.32mm.....


Sorry, measured across where :?:
That would be an ecumenical matter.

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Tue Jul 17, 2012 1:23 pm

Probably easier if the mods want to move this thread's Class 40 detour to a new thread.


Horsetan wrote:
ClikC wrote:.....the distance beteen the lip of the cab window front is 9.32mm.....


Sorry, measured across where :?:


I've Edited the orginal post to correct. But from the lip of the cab roof front too the cab roof ventilator.

Image

The Cab doors on the lima model are the right width, but they taper inwards which make them look overly narrow. The body center door is the right width, and the distance between the edge of the center door too the cab doors is the correct 261". All the side doors are of course (along with the rest of the side detail on the model) too tall. The Cabside windows messure 24" across the top, and are 25.5" tall. The distance between the inside edge of the 3" rad on the triangular extra bit of the cabside window to the rear inside edge on the door pillar is 32.5". The center of the cabside window (not including the triangular bit) to the underside of the cabside body is 53.5". That last messurement is a little tricky, as the taper on the underside of the lima nose starts under the windscreen pillar, but on the prototype it starts a little forward of that just behind the bearer pad. Basiclly speaking the top of the cabside window, and the door pillar edge is in the correct possition, you'll need to pack out the inside edge of the cab windscreen pillar, and file downwards to obtain the correct height, and the correct possition of the cabside windows.

Last time I was activily persuing this project (I bought along this body to scaleforum 2010), Brian Hanson of Shawplan was in the process of drawing up a complete profile of the Class 40 in CAD, with the aim of laser cutting a side almost as a template to show where everything whould be. It is of course thanks to him I'm managed to get so far with the lima shell.

Regards

Matt
Last edited by ClikC on Tue Jul 17, 2012 1:28 pm, edited 2 times in total.
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby John Donnelly » Tue Jul 17, 2012 1:25 pm

This thread has grown legs since my original post :D

I'm going to try running the 46 as a BO-BO tonight to see if that makes a difference - with regards to the track, it may still be an issue with the turnout albeit out of 4 items of rolling stock I have (the class 20, a bogie parcels van and, as of a couple of days ago, a class 08), the 46 is the only one that has a problem negotiating the turnout.

I may try removing the spring on the trailing axle to see if that make any difference as well.

John

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Horsetan » Tue Jul 17, 2012 1:39 pm

ClikC wrote:.....I've Edited the orginal post to correct. But from the lip of the cab roof front to the cab roof ventilator.


Thanks for the clarification. I take it from the photos that your saw cuts also went horizontally across the cab door?

johndon wrote:This thread has grown legs since my original post :D....


They generally do if I'm involved :twisted:
That would be an ecumenical matter.

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Tue Jul 17, 2012 2:03 pm

Horsetan wrote:
ClikC wrote:.....I've Edited the orginal post to correct. But from the lip of the cab roof front to the cab roof ventilator.


Thanks for the clarification. I take it from the photos that your saw cuts also went horizontally across the cab door?


Yes, to just behind the raised section of the cabdoor inside the moulded lima body. I've some lovely etched cab doors which were going to make it onto this project, but I'm inclinded to save them for the new Bachmann 40. As with the being my favorite locomotives, I really want to do them justice.

I belevie the Mostyn boys scratch built some cab doors for their 40's, covered in REx No.115 (Supplement No.20)

Regards

Matt
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby grovenor-2685 » Tue Jul 17, 2012 2:48 pm

Matt,
Any chance you could draw lines on your pic to show where all these sawcuts were? I am having great difficulty trying to visualise it.
Regards
Keith
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Keith
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby ClikC » Tue Jul 17, 2012 3:15 pm

grovenor-2685 wrote:Matt,
Any chance you could draw lines on your pic to show where all these sawcuts were? I am having great difficulty trying to visualise it.
Regards
Keith


Keith, I've only access to MS paint on this, so please forgive the crudeness, but I hope these help.

Image
Image

Regards

Matt
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby Horsetan » Tue Jul 17, 2012 8:57 pm

Aha, I get it now. Thanks, that clarifies a lot!
That would be an ecumenical matter.

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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby grovenor-2685 » Tue Jul 17, 2012 10:40 pm

Matt, thanks for that, I can now see what you meant.
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Keith
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Re: Bachmann 46 to P4 using Ultrascale conversion

Postby jim s-w » Tue Jul 17, 2012 10:41 pm

Hi John

I hope the following reassures you that the Bachmann peak will work in P4.



Cheers

Jim
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