Another Method for making a ‘Chuff Cam’

Sometime ago I did a post on how I make ‘chuff cams’ for model steam locomotives using Super Glue (ACC).

Erik Bennett sent me an email recently with his method so I asked him if he minded if I posted on the blog. As a result with Erik’s agreement here is his method for setting up a ‘chuff cam’ on a model steam locomotive.

Hi Ray,

I’ve put chuff cams in a number of locos, previously using a piece of 35mm film negative, cut to shape and superglued to the back of the wheel.

I saw your blog a few months ago where you described the technique of painting superglue on the back of the wheel.

Knowing how hard superglue is when it sets, I thought it a great technique and decided to try it on my next loco.

Well, I just finished a loco and it works great.

So, thank you for posting your superglue technique.

For info, I modified your method slightly and offer it here as an additional method:

I found it a bit tricky to get a clean edge when free-painting using the pencil mark method.

So I cleaned the superglue off my early attempts and cut 4 identical strips of adhesive tape.

The strips were about 3/4 the radius of the wheel in length and wide enough so that four strips gave four equal make & break sequences.

I actually used Tamiya painting tape and put 4 bits on top of each other on a pane of glass, then did my cuts.

Bearing in mind that the chuff sound is made on the break (not the make), I marked on the wheel where the break should be in relation to the pickup contact when the rods are TDC (Top Dead Centre - RP) as the wheel rotates forward.

I positioned the first strip radially outwards so its trailing edge was aligned with this mark. The longish length of tape makes it easy to align radially.

I then positioned the other three equidistant around the wheel.

Then I painted superglue as evenly as I could in the bare spaces between the strips.

I let it dry for a day, removed the tape and gently smoothed any raised edge where the superglue had interfaced with the tape.

I ended up with 4 nice tough break surfaces!  And nice chuff sounds when the engine runs, synchronised with the rods.

So thanks once again; your method is much easier than the 35mm film.

 

Best regards,

Erik

Thank you Erik it is nice to get feedback about the blog and I am glad it got you thinking to come up with this more sophisticated version of the ‘chuff cam’.

7mm Scale Clearance Posts with Lamps

New Addition to the 7mm Scale Range

7mm Scale Clearance Posts with Lamps have been added to my Signals Branch Shapeways Shop since my last post, these are printed in Frosted Ultra Detail material and have been designed so that a 3mm LED can be inserted into the bottom of the baseboard mounting to have them lit.



View from below

3D drawing

Shapeways Frosted Ultra Detail Render

Of course these clearance posts with lamps are also available in HO on my Signals Branch Shapeways Shop.

Sorry for these types of posts, the 3D designing and printing has kept me sane over the last 12 months.

I will get back to the usual type of posts soon.

Back again after my longest break in posts

I felt I had to take a break from posting on the blog so please accept my apologies. At home here we are coming up to 12 months since we lost our lovely daughter Kirsty and the last few months have been difficult for Chris, Bonnie, her boys and myself.

I have tried to keep my interest in the hobby going more as a distraction than anything else, the layout has had nothing done to it since March last year, but it will return to the blog.

So inevitably I have been working on some 3D printing stuff as the mental exercise works well.

As mentioned in previous posts I was working on several projects that have now been made available on my Signals Branch Shapeways Shop.

With apologies for the repeated photos, these items are:

• NSWGR A Frames in HO and 7mm Scales (point rodding supports from lever frames).

7mm Scale A Frames (HO track behind)



HO A Frames - Still to be glued in place

• A range of Fine Detail HO signals in Frosted Ultra Detail (FUD) and so far I have single arm 16ft - 30 inch arm, 18ft - 30 inch arm, 23ft - 36 inch arm and 27ft - 39 inch arm signals, more signals and arm types will follow as I find the time to draw them up.

HO A Frames and high resolution FUD signal

• NSWGR 1924 Derail in HO, a track arrangement at the end of a siding where it meets a main line to prevent wagons from fouling the main line. The plan below is also available on my Signals Branch Blog in the Links section.

• NSWGR 1936 Catch Point in HO, a more complicated version of the Derail with a moveable rail and a catch point indicator (a ground signal). The plan below is also available on my Signals Branch Blog in the Links section.

• NSWGR Catch Point Indicator in HO and 7mm Scale that can be made to work from a rod to the moving catch point blade.

7mm Scale Pilot Model Test Print

• A range of 7mm Scale signals in White Strong and Flexible (WSF) and so far I have single arm 16ft - 30 inch arm, 18ft - 30 inch arm, 23ft - 36 inch arm and 27ft - 39 inch arm signals, more signals and arm types will follow as I find the time to draw them up.

'Proof of Concept' trial 7mm Scale 23ft signal

The above 7mm Scale signal  doesn't represent what is available as more detail has been added along with a couple of minor corrections.


More information and instructions for the above items can be found at my Signals Branch Blog.


Now a Possible Challenge for the N Scale Modellers

I have recently received a 3D print of a NSWGR 23ft signal as a 'Proof of Concept' trial.

The signal would be a challenge to assemble as it requires drilling some holes with a 0.3mm drill bit (smallest drill bit I know of) and using 0.008" (0.2mm) phosphor bronze wire from Tichy Train Group (Part #1100 - 10 lengths) as the operating wire. The modeller will have to have a steady hand and good eye sight.

One thing became obvious and that is that the counter weight lever on the post is probably going to have to be static with the operating wire coming up from the mechanism below to the arm. The reason for this is that holes to be drilled in the lever for the pivot and operating wires would mean that the lever would have be thickened too much and would look very wrong. The amount of movement it would go through would be quite small and also the holes being 0.3mm and the operating wire being 0.2mm the slop could cause operating difficulties. I am not sure how this can be got around for bracket signals, I will have to think about that.

The trial signal arm is pivoting on a brass pin and the usual method of printing the pivot shaft with the signal was not good as the shaft broke easily, more to think about.

Of course the signal could be made non-working.

Anyway at the moment the possibility of adding N Scale signals to my Signals Branch Shop at Shapeways is a reasonable bet unless I run into some problem I can't solve.

Now just to show that it can be made to work here is a video:

I hope that this post has been of some interest.