CSB for a Class 14 Diesel?

[down_under]

Hello All,

Short answer - yes - it is possible to CSB Mike Edges' C.14 Chassis.

I worked on this one earlier this year.

Specs
High Level 13/20 coreless (excellent motors)
High Level 60:1 High Flier
High Level Space Saver Hornblocks
Markets short handrail knobs for CSB pivots (M4HRKS1.2)
Alan Gibson C.14 wheels (3 x 4S47D) & flycranks (1 x 5002)

Here are my CSB workings

C.14 CSB workings_as built.PNG

A little bit of tweaking gets the CSB plot to this, which according to my notes is what I actually built it to

C.14 CSB workings.PNG

And here are some pictures of the build. The chassis is, as Mike notes, narrow due to the prototypes design. Thus I recommend High Level Spacersaver hornblocks. Due to the design of the laminated cosmetic hornblocks, I used some 800 wet & dry to rub down the outside face of the hornblocks by a few thou to ensure some working clearance - see picture below.

Because of the narrowness of the chassis - I fitted a high level High Flier (7.8mm wide), though that is not to say other combinations wont work (D1 driver stretcher + load hauler?). Coupled with a slow revving but torquey motor gives realistic top speed and slow speed control.

Coupling rods jointed - I used 1mm n/s rod to make the pivots. I cheated a little using a spare pair of rods to enable a proper forked joint.

C.14 Coupling Rods.jpg

General CSB layout - note the working clearance is minimal between cosmetic and working hornblock. It does work however there is enough flex to get the 0.5-0.8mm of travel.

C.14 underneath.jpg

C.14 CSB.jpg

And next to the body - cruel shot before tidy up of the solder. I used all the lamiantes to build the cosmetic hornblocks. Even then I still required a couple of 0.1-0.2mm spacers to remove the side play from the wheels.

C.14 Chassis and Body.jpg

Mods to Heljan model - you will need to carve out a fair bit of metal from the factory weight due to the new motor location. The plastic footplates needs a little trim on the inside to accomodate the cosmetic springs (especially if you use all the laminate).

Side shot with long term shelf queen, a YE Janus (Oxford Body, Judith Edge Chassis)

C.14 and Shelf Queen.jpg

Still to fit, pick ups, brake gear and torque link for motor.

Hope that helped.

James

Edited with correct CSB plot as built.

[down_under]

To answer the OP's questions:

Hi all,

I have one of Judith Edge Kits' new chassis kits for the Heljan Class 14 on order. The chassis kit comes with compensation, but I'm considering attempting a CSB solution. What I'm unsure of however is how to handle the fourth axle on this loco which carries the crank pins. Can this be left rigid to the chassis because it doesn't have any wheels fitted, or does it need to be sprung?

Leave the jackshaft axle ridged, it does not need to be sprung

Also, I'd appreciate your thoughts on whether this project is too ambitious for a first effort at CSB, and also the first chassis I've built in a long while? Would the performance with CSB be much better than just building it with compensation?

If you take your time, I personally don't think that you will have problems. This was my fourth attempt at building a CSB'd loco (they've all worked), and second 0-6-0, although with the number of joints the rods are more like a 0-8-0 (just articulate on the crankpin if you don't fancy forking all the joints). The parts go together well. It is a basic 0-6-0 at heart.

Use Chris's CSB jig - for this model I used the B height. This jig makes life so much easier.

Like I mentioned in the previous post, you may need to use some wet and dry to take a few thou of the outer face of the hornblocks to ensure that you have some working clearance between the working and costmetic ones.

The cosmetic hornblocks look tricky - I used an old 1/8th axle bush and a straight edge to get them all lined up. I trialed both laminating 5 in one go vs completing in two passes - tbh it was just as easy either way.

Oh and just make sure that you clean up the solder / flux as you go along - keeping things clean and with it being n/s it solders well.

Thanks,

Liam

[davebradwell]

I'm having great difficulty following this last because you're making no distinction between the hornblocks which are fixed to the frames and the axleboxes which slide in them. This has become a common issue.

Moving on, might it be possible to drive the jackshaft or does the body prevent this? With coupled wheels that roll on the rails this tends to assist the coupling rods and helps smooth any slight tightness. With the jackshaft in mid-air it won't receive this help. Chris Gibbon arranged a geared drive to the jackshaft on his 04 chassis in case of difficulties here - it also cuts out any possible problem with differing crank throws or errors in rod hole centre for this joint. Driving only the shaft won't do all this, of course but I feel it's a better place to start. Yes, I realise that when wheels are slipping it's just the rods doing the driving.

A thought for the knuckle joints in the coupling rods - by using 1/32" rivets on the pivots a risky soldering job can be eliminated. File snap head to a hex, put through knuckle ,countersunk at rear, cut rivet slightly long with side cutters and gently tap burred end into countersink - it only has to prevent rivet coming out so don't bash it down tight. File off excess so it doesn't hit boss on wheel.

DaveB

[Triode]

Hello All,

Short answer - yes - it is possible to CSB Mike Edges' C.14 Chassis.

I worked on this one earlier this year.

Thanks very much for posting this James. I've got no excuse for trying it now!

Can I ask a very basic question: at what stage of the assembly did you cut out the slots for the hornblocks and fit the hornblock guides? My worry is that once the hornblock guides are cut out, the circular rigid axle bushing holes in the etch are lost, and I would have thought these are crucial in lining up the two chassis sides for soldering?

Cheers,

Liam

[Crepello]

Chris Gibbon arranged a geared drive to the jackshaft on his 04 chassis in case of difficulties here - it also cuts out any possible problem with differing crank throws or errors in rod hole centre for this joint. Driving only the shaft won't do all this, of course but I feel it's a better place to start.

Unless Chris has revised the design since I bought mine, he did this because the jackshaft isn't connected to the coupling rods, the gearing just gives the illusion of being so. The gearing for the jackshaft is taken from the adjacent axle, which dashed my hopes for springing my 04.

[davebradwell]

...and I suggest he didn't connect the jackshaft to the rods in order to avoid having to exactly match the stroke of the crank with the wheel throw. It's also one less pair of rods to worry about. It would be a way of doing the 14 but you'd have to source some suitable gears.

Can't see why you couldn't spring the axle with the gear drive on it.

DaveB

[down_under]

Hello All,

Short answer - yes - it is possible to CSB Mike Edges' C.14 Chassis.

I worked on this one earlier this year.

Thanks very much for posting this James. I've got no excuse for trying it now!

Can I ask a very basic question: at what stage of the assembly did you cut out the slots for the hornblocks and fit the hornblock guides? My worry is that once the hornblock guides are cut out, the circular rigid axle bushing holes in the etch are lost, and I would have thought these are crucial in lining up the two chassis sides for soldering?

Cheers,

Liam

Hi Liam,

In this instance I cut out the hornblocks before soldering the chassis up. However, I did solder up the chassis on the workbench using some simple wooded jigs - inspired by Ian Rice. The accuracy of the half etch lines for the chassis spacers in spot on - just need to make sure that you solder them in square. I think it took me two attempts before I was happy. You can see in this post here (dont have a photo of the C.14, but the FELL was built in similar style) - viewtopic.php?f=19&t=7877&start=25#p99776 that I use(d), what is essentially a 12mm slot routed in a piece of MDF, that a 12mm square baton locates to form my right angle. I then solder the frame spacers to one side and then offered up the other side. The half etch ensure that you will get the frames pretty much spot on.

Since the jackshaft is not cut out, it can be used to ensure alignment - especially if you have a jig (Avondside or Hobby Holidays, or a home made one).

Just ignore the spacersaver hornblock in this photo - I was checking the fit of the horn guide against the spacer (it needs a little trim ~0.5mm filed off one side)

IMG_5131 (1).jpg

Once it was square, with both sides in, I then added the high level hornblocks and guides, followed by the cosmetic axle boxes - note I used some old 1/8th bearings to help with alignment. These worked for me, i',m sure there are other ways around this.

IMG_5593.jpg

Hope that helped.

J

[down_under]

I'm having great difficulty following this last because you're making no distinction between the hornblocks which are fixed to the frames and the axleboxes which slide in them. This has become a common issue.

Thanks for the correction, will amend post. That should read - " rub down the outside face of the High Level working axlebox to gain
a working clearance between it and the cosmetic axlebox / spring assembly" Otherwise i found that the gap was just a little on the tight side. Hope this sketch makes more sense?

IMG_6510.jpg

Moving on, might it be possible to drive the jackshaft or does the body prevent this? With coupled wheels that roll on the rails this tends to assist the coupling rods and helps smooth any slight tightness. With the jackshaft in mid-air it won't receive this help. Chris Gibbon arranged a geared drive to the jackshaft on his 04 chassis in case of difficulties here - it also cuts out any possible problem with differing crank throws or errors in rod hole centre for this joint. Driving only the shaft won't do all this, of course but I feel it's a better place to start. Yes, I realise that when wheels are slipping it's just the rods doing the driving.

You could motorise the jackshaft - would need a driver stretcher (if using High Level Boxes), or a remote drive to avoid the motor in the cab problem, secondly I didnt fancy modifying the chassis spacers, and just worked around them. There was a slight bit of binding when COG towards the long nose. I just adjusted this and then tweaked each connecting rod bush one at a time until it ran sweetly

A thought for the knuckle joints in the coupling rods - by using 1/32" rivets on the pivots a risky soldering job can be eliminated. File snap head to a hex, put through knuckle ,countersunk at rear, cut rivet slightly long with side cutters and gently tap burred end into countersink - it only has to prevent rivet coming out so don't bash it down tight. File off excess so it doesn't hit boss on wheel.

Nice suggestion, I will try that on the next one

DaveB

[Triode]

Hope that helped.

J

Yes, that's a big help thanks James. How did you set the horizontal distance between the hornblocks/axles? I have seen it done by others by slipping the connecting rods over the ends of the axles to ensure they all end up at the correct positions. Given that the rods need to be cut up and jointed I suppose this would have to be done before that step?

Once I get started on my attempt I'll post progress here.

Cheers,

Liam

[davebradwell]

Yes, I get it now James so thanks for that - I wondered if you had put the HL hornblocks on the outside and not so. You've done a thorough job tweaking the coupling rod centres and I could never get the jigging to give sufficiently accurate results without this step.

Liam, the essential jig setting of hornblocks is done with special axles and there'll be a wall of posts to guide you on this. As for using rod before adding joints this poses a good question - can you joint the rods without making even tiny changes to the centres? I suspect not, although the jointed rods will be much more awkward to use.

DaveB

[down_under]

Hope that helped.

J

Yes, that's a big help thanks James. How did you set the horizontal distance between the hornblocks/axles? I have seen it done by others by slipping the connecting rods over the ends of the axles to ensure they all end up at the correct positions. Given that the rods need to be cut up and jointed I suppose this would have to be done before that step?

Once I get started on my attempt I'll post progress here.

Cheers,

Liam

Hi Liam,

No problem man. Regarding setting the distance between the axles - yes I used the connecting rods. As Dave notes, a search on the forum should throw up and few posts on this. The below assembly worked for me:

Before I cut the rods,

1) drilled and bushed the rods, (used a pillar drill and reamer) > used these to set the initial axle spacing on my jig.
2) split the rods in 3 and laminated them section by section. Cleaned up, filled, filed in separate parts.
3) starting with the middle section, checked / reamed to ensure it fit on the jig.
4) repeated the above step with the outer sections, soldering the knuckle joint (or alternatively riveting) when happy with the fit.

The key for me was if in doubt check, check again, ream little by little.

By splitting and articulating the knuckle, there is a risk as Dave notes of introducing a error (if the knuckle hole is not vertical for example). If you don't fancy articulating on the knuckle just articulate on the crankpin and skip the last step.

Mikes kits are pretty good being CAD designed the axle spacing and rods match (I checked against the chassis before I cut the hornblocks)

When I finally assembled mine there were a few tight spots, so I just worked my way along wheel by wheel (start as 0-4-0, then 0-4 + jackshaft, then 0-6-0) to find the tight spot and ream as I went. The result was a free running chassis.

Much of this was trial and error through a few earlier builds. If you mess it up, a short email to Mike usually results in a spare set of whatever you need. When it got frustrating I moved onto other bits like laminating the axle boxes.

Hope that helps


You might find this post useful https://www.rmweb.co.uk/topic/45248-jud ... nt=4798685 it shows pictures of the test etch being built by Mike.

[down_under]

Yes, I get it now James so thanks for that - I wondered if you had put the HL hornblocks on the outside and not so. You've done a thorough job tweaking the coupling rod centres and I could never get the jigging to give sufficiently accurate results without this step.

Thanks Dave

I did contemplate sticking the HL hornblocks on the outside, but decided against hacking the cosmetic spring / axle/hornblock assembly


Liam, the essential jig setting of hornblocks is done with special axles and there'll be a wall of posts to guide you on this. As for using rod before adding joints this poses a good question - can you joint the rods without making even tiny changes to the centres? I suspect not, although the jointed rods will be much more awkward to use.

DaveB

[Will L]

... Regarding setting the distance between the axles - yes I used the connecting rods. As Dave notes, a search on the forum should throw up and few posts on this...

Also try here viewtopic.php?p=6738#p6738

[down_under]

... Regarding setting the distance between the axles - yes I used the connecting rods. As Dave notes, a search on the forum should throw up and few posts on this...

Also try here viewtopic.php?p=6738#p6738

Thanks Will! Excellent photos and description!

[Winander]

Lanarkshire Models do a universal coupling rod that is appropriately jointed http://www.lanarkshiremodels.com/lanark ... te_048.htm