McIntosh Patent Brake

How to do it, advice sought and offered.
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Alan K
Posts: 360
Joined: Mon Aug 13, 2012 9:41 pm

McIntosh Patent Brake

Post by Alan K »

I've had a go at constructing one of these from the new TLM CRA3 etch. For reference I used the item in TL67 reproduced from the 1900 Railway Engineer, but it turns out that there is another Railway Engineer item showing the mechanism that Ian Terrell used in designing the etch - more of that later.
I started with the more familiar parts, ie the push rod and brake shoe parts 2, 3L, 3R, 4, 5 and 6 shown here
IMG_4283.JPG
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I used one item as a guide to drill (0.4mm diameter) through each hole into a scrap piece of MDF and inserted pins made from brass 0.376mm wire into the holes. Each layer was tinned on both sides (except for the front face), and placed in order over the pins with the outside surface on the bottom. Then hold down the free ends (with a scrap of wood) and apply soldering iron! Very small amounts of solder required. I use 145 degree solder wire, and cut the tiniest pieces I can with wire cutters. Solder paint is an alternative, but I'm not sure if that is available in 145 deg.
The photo shows the detail - one side already done on the left, the side on the right just soldered.
IMG_4271.JPG
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The pins are left soldered in place, to be either cut and filed down to bolt head size or used to locate the pivot arms attached to the inner V hanger unit, and then filed down. So you end up with this:-
IMG_4272.JPG
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I chose to drill out all 4 outer V hanger holes (part 14) and use it as a guide to drill holes through the solebar. This turned out to be too ambitious - drilling 4 holes and expecting everything to line up nicely with pins soldered into the holes led to problems and I had to open up the holes in the solebar quite significantly. Next time, I'll only drill out 2 holes to insert pins and dimple the other 2 to form cosmetic bolt heads. With only 2 holes there is less scope for inaccuracy! Wooden block used to locate pins while soldering, then file down pins as shown here
IMG_4275.JPG
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The wire through the V hangers is 0.7mm diameter.
Then all that's left is to fit the safety hangers (13). These can be soldered onto the base, which is much better than having to use epoxy. One should be shorter than the other other, but it's an easy job to fold.
The lever arrangement is the part which is 'different' from the conventional Morton type arrangement. I soldered parts 7 and 8 together in position. But there is a problem with the outside lever (8) ie the one with the 'pointy ' end : it's too short and needs to be lengthened otherwise after the bends are made for it to clear the axlebox (as with the Morton type lever) the end comes out above the axleguard and not beyond it. So I had to lengthen it by 1.5mm. I cut it and soldered a thin strip of nickel silver onto the back to make the joint. I did it the lazy way by cannibalising part of the same lever from another fret, but the next time I'll make a little wooden jig to hold everything registered against one straight edge and solder a little 1.5mm extra piece onto the backing strip. Here is a photo of the back of the lever showing the added strip to the right of where the light is catching on the curved part.
IMG_4285.JPG
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Two more pictures to show of the cross-shaft and fixing onto the wagon, but I've used my quota of 5 pictures!
Alan K
Posts: 360
Joined: Mon Aug 13, 2012 9:41 pm

Re: McIntosh Patent Brake

Post by Alan K »

This is the version of the patent brake shown in TL67:-
Railway Engineer 1900.jpg
Railway Engineer 1900.jpg (41.16 KiB) Viewed 7819 times
There is another Railway Engineer item which Ian used for the design of the etch here:
McIntosh brake Railway Engineer 1899.jpg
McIntosh brake Railway Engineer 1899.jpg (29.5 KiB) Viewed 7819 times
There are subtle differences, mainly to the crank on the cross-shaft. Basically, the handle is attached to the cranked end of the cross-shaft at the brake shoe side of the wagon, and when rotated it forces a collar (part 10) - which is positioned around the neck of the lever- to lower the lever and apply the brake. There is a cam and spring arrangement on the cross-shaft under the wagon which holds the position in place. The two part 9 items are attached to the solebar at each side, with the bottom hole projecting below the solebar to hold the cross-shaft in place. I drilled out the top 2 holes in each and used these to drill holes in the solebar to take soldered-in pins. The holes in the folded over collar (10) and the handle/guard (12) fix over the projecting cranked end of the cross-shaft and are soldered together. This completes the brake shoe side:-
IMG_4281.JPG
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The wagon is lying on its side, so the wheel sets have dropped down and the brake shoes don't seem to match the wheels, but when it's sitting on a horizontal surface, the brake shoes line up very well I can assure you!
The other side of the wagon has only the handle fixed onto the other end of the cross-shaft. I wanted a longer handle for that side as per the drawing, so I cut off the arm of the 2nd part 12 item and soldered a longer arm made from scrap which could be cranked out as shown in the drawing. The photo shows the non-brake shoe side:
IMG_4284.JPG
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You can get a clearer view of the cross-shaft (made from 0.45mm brass wire) and the part 10 fixing.
So that's it complete! I think that it went together very well - having to lengthen the lever is a bit of a nuisance, but it's fairly strightforward to overcome. You end up with a nicely finished alternative brake arrangement which can give more variation to your wagon fleet! I shall certainly be making more.

Alan
Steve Parsons
Posts: 426
Joined: Thu Jun 12, 2014 9:01 pm

Re: McIntosh Patent Brake

Post by Steve Parsons »

Thank you Alan that's very useful and informative, I'm sure I must have been one of many who was struggling to get there head round the workings of this brake system but this helps to make it clearer.
Steve
Alan K
Posts: 360
Joined: Mon Aug 13, 2012 9:41 pm

Re: McIntosh Patent Brake

Post by Alan K »

Thanks Steve. The key ingredients are the crank in the cross-shaft and the collar over the lever to pull it down.
I don't know when American sexual innuendo slang came into prominence this side of the Atlantic but I suspect it was later then this period, so 'hard on' probably would not have had any other meaning for turn-of-the-century Scottish shunting personnel!
I almost forgot about part 11. I puzzled over this until I got in contact with Ian. When suitably folded up, it makes an alternative handle ie without the guard. I suspect that this was the more numerous version if the proportion of photos in the Wagon Book are anything to go by. Unfortunately you only get one! But if you have purchased 2 frets you'll get a pair and I shall make the next one without the guards on the handles.
I have an idea for a little home-made device (made from a Costa coffee stirrer!) to hold the two parts of the lever in place while soldering in the extra 1.5mm when lengthening, so watch this space!

Alan
tony brenchley
Posts: 328
Joined: Sun Aug 26, 2012 9:36 am

Re: McIntosh Patent Brake

Post by tony brenchley »

Thanks Alan

Excellent work and an inspiration to all of us who have the McIntosh brake etches.

I40 solder is available as 138 solde4r cream from Carr's in a syringe. Very useful stuff!

Tony B
Alan K
Posts: 360
Joined: Mon Aug 13, 2012 9:41 pm

Re: McIntosh Patent Brake

Post by Alan K »

Actually this highly sophisticated device is made from parts cut from a Costa coffee stirrer mounted on a wooden chip fork! I wanted to come up with a systematic way of restraining the parts while soldering up the extra length of the lever. This is what it looks like:-
IMG_4333.JPG
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The small wooden strips were glued in place using the original lever straight from the fret. They need to be quite tight against the lever's edges, and there needs to be a gap in the middle to give access for the soldering iron tip.
Now turn over the lever so that the inside face is uppermost , make the cut and push the ends apart by the amount to be lengthened:-
IMG_4286.JPG
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In this picture, the surfaces have already been tinned. I should point out that in this case the amount to be lengthened is double (ie about 3mm) as I'm using up the lever which I cannibalised when I made the first lever. Normally, the gap would only be 1.5mm. The strip to be soldered in to overlap the gap is shown at the top. It just needs to be held down and the soldering iron applied, with the little wooden blocks holding the two parts of the lever in place.
The next picture shows the lever soldered-up and turned over ready to receive an extra length of strip cut from the fret scrap. This needs to be filed to length so that it just fits nicely into the gap, but the width can be left to be trimmed after soldering.
IMG_4287.JPG
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The lengthened lever after cleaning up to remove excess solder and smoothing down with fine wet and dry glued to a block of wood looks like this:-
IMG_4331.JPG
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Then all that needs to be done is to file the edges to blend into the taper of the lever. This needs to be done carefully - I found the best way was to hold it with pliers while filing.
Finished lever. The length from tip to tip needs to be about 28.5mm or even a little more to clear the spring hanger after bending to shape. Care needs to be taken when bending to shape to support the joint.
IMG_4332.JPG
IMG_4332.JPG (103.41 KiB) Viewed 7716 times
For the backing strip, I used 0.15mm thick nickel silver strip which was ideal, but pieces of fret scrap could be used just as well and filed down thinner after soldering.

Alan
Oh and thanks for the info about the low temperature solder cream Tony. I must try and get some.
David Elvy
Posts: 453
Joined: Tue Aug 21, 2012 6:26 am

Re: McIntosh Patent Brake

Post by David Elvy »

Thank you for sharing, that's one for the how to do it book.

David
Alan K
Posts: 360
Joined: Mon Aug 13, 2012 9:41 pm

Re: McIntosh Patent Brake

Post by Alan K »

I've now finished off a couple of wagons fitted with the 'either side' brake.
IMG_4336.JPG
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They are rather grubby D46 wagons, many of which had this type of brake. Alas, they are not the True Line Models ones, but MWC white metal ones which had lain around too long unfinished. I wanted two fitted with coke rails for servicing the boilerworks yard on my layout.
In this cruel close-up, you can see the additional features of the Patent Brake: the pin and chain arrangement between short and long levers, and the curved instruction label.
IMG_4337.JPG
IMG_4337.JPG (170.95 KiB) Viewed 7644 times
I'm quite pleased with the chain, but claim no credit for the method of making it - that was from Mike Williams's description in his notes for the R Y Pickering Private Trader Wagons. It is exactly as he says -the chain forms as if by magic. A really good tip - thanks Mike!
I'm not so pleased about the instruction label. It's too small to reproduce in 4mm, and so can only be an impression. But I had already fixed the 'Load 8 tons' lettering in place before I realised after looking at p48 of the Wagon Book that the lettering is purposely displaced to the left to allow the higher position of the brake label. So some regrettable language was uttered. But it's done now and I ain't gonna change it!
Incidentally the paint for the wagons was Windsor & Newton Artists' Acrylic Red Iron Oxide (another alternative!) liberally weathered with Lifecolor Roof Dirt acrylic.

Alan
jasp
Posts: 496
Joined: Mon Aug 20, 2012 5:40 pm

Re: McIntosh Patent Brake

Post by jasp »

Good to see your work on the McIntosh brake.
The wagons look great.
How about a piece on your weathering technique.
Jim P.
David Elvy
Posts: 453
Joined: Tue Aug 21, 2012 6:26 am

Re: McIntosh Patent Brake

Post by David Elvy »

Jim

You read my mind, lovely weathering finishes off the model. any hints you could share Alan?


David
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