Detail view of linkage showing connection of piston rod, connecting rod to guide arms. A touch of Loctite on the screw threads should hold everything nicely in place on assembly.
With the cylinder and steam chest completed the next stage was the fabrication of linkages, eccentric and flywheel. Most of these items are relatively straightforward though it pays dividends to take your time and make each component as precise as possible. It’s tempting to rush the final stages but to me this is a mistake. Hurried workmanship now can so easily result in hours of frustration when your engine refuses to run.
One problem with Elmer’s plans is the quality, or lack of, of the pictures featured in the build notes. At first I had a struggle trying to sort out the detail of the linkage relating to the connection of piston rod and connecting rod. I think I have resolved the dilemma and the picture on the right shows my final result. I hope this is of some help to those of you following this build. I was also unsure on Elmers method of retaining the connecting links to the arms and you will see my solution in the gallery of build pictures.
By the way, with building my engine 50% up on Elmer’s plans I had to source a 4.5″ flywheel. Surfing the net took me to martins models I can highly recommend these top quality flywheels, beautifully cast with an excellent selection of styles and sizes. At the moment the $20 flywheels come into the country without attracting customs and excise duty which currently applies on items exceeding £18.00 in value.
So with a glimmer of light at the end of the tunnel I set about the final stages of completing Elmers #32
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- Studs were made for both guide arms from 3mm stainless and threaded M3 at both ends. After silver soldering the centre piece was cut away.
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- As I din’t have a convenient piece of 50mm dia. brass the crank wheel was fabricated from aluminium plate and rough cut by hacksaw.
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- The ‘Flinstone’ styled wheel was clamped up in an arbour and turned down to size. Note ‘rough cut’ index cutter in toolholder.
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- Over to the mill for shaping the crankwheel. A large diameter end mill provided the profile I needed.
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- Switching from horizontal to vertical was the best way of arriving at the final shape for the crankwheel.
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- After cleaning up the spokes with a hand file the flywheel was set up in the three jaw for final finishing.
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- A drill bit holds everything in place during trial assembly of linkage. This is the pic that is hard to decipher from Elmer’s build notes.
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- Trial set up of crankwheel and flywheel on crankshaft. Everything checked for smooth free running.
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- Testing the motion of the running gear. Care and accurate maching will have paid you dividends when you arrive at this stage.
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- Any slight stiffness in the running gear will disappear during the running in process. More serious binding needs to be sorted before proceeding.
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- My final machining job was the eccentric. You need a 4 jaw independant chuck for this – simply follow Elmer’s build notes.
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- The completed eccentric turned from mild steel bar – the final piece in the jigsaw.
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- An overhead view of the crankshaft, flywheel and linkage down to the cylinder and steam chest.
It was at this stage in the proceedings that I couldn’t resist putting some air through the engine to see if there were any signs of life and I am pleased to report that after just a few minor adjustments my new creation burst into life !
Good Morning John,
Will do. I built my Vertical to original scale, there being enough intricacies in the original design to more than challenge my skills.
I note that several of your completed models seem to be powder coated, and I wonder if you could give me a little advice on the process.
Many thanks,
Brian
Hello Brian
Apart from a little extra work in adjusting the dimensions on the plans I found that building to an increased size was no more difficult, in fact almost the opposite as the larger components are less ‘fiddly’.
I am not too sure about the fine detail on powder coating except that items are sprayed with a dry paint powder then heat treated in an oven and provides a very tough paint finish. It’s a popular treatment with motorcycle restorers for that reason. I have a local company who will add a model engine frame or chassis to one of their batch runs for the cost of a pint. I make a point of showing them the finished engine on completion and they seem well pleased – or maybe they are just being polite. Two things to bear in mind – do fill any drilled or tapped holes to prevent paint entry and allow for the fact that often powder coating can be quite thick so could affect tolerances. The alternative method I use for most of my models is a brushed coat of etching primer followed by several coats of aerosol car paints from Halfords. Then leave for several days to fully harden. I use a large cardboard carton on its side as a spray booth. It’s easy to suspend wire hooks inside the carton to hang components.
John
Hi John,
I am a bit of a disappointment I’m afraid. I note the date of my last comment, with the promise of beginning Elmer’s Vertical Mill Engine- and then silence! Well here I am again after much delay, but finally at the assembly stage. I got a bit side tracked! As you described, I too, puzzled over the linkage conundrum, and thought for a moment or two that the arms just might be too long. Of course there was no mention of soldering and cutting the pins as you describe, but that certainly seems the only sensible course. I like your approach using nuts and studs and plan to adopt that method as well- it ‘feels’ better. I have the engine and steam box complete, and have what appears to be a satisfactory valve- milling that up using a 50 yr old cast iron Atlas Milling Adapter was a treat! I had to permanently affix Dial Indicators to the Y and Z axises to compensate for backlash but it worked. It fits very nicely into the nut.
I also liked your superglue approach to dividing the head bolts- I had seen that here before and promptly forgot about it. It might have saved me some headaches!
It is very encouraging to see Your finished efforts and realize what can be done with a little care and effort. My tooling is rudamentary, but I feel it is all within reach. Elmers’ Vertical is my third engine since retirement, but the most exacting.
Hello Brian
I was really pleased to hear from you and that you are into the final stages of your build. What I want to know is did you build at Elmer’s size or increase by 50% ? I would love to see pics of your finished engine and maybe you would also consider adding some notes on how your build progressed. Such information is often very useful for others.
John
A superbly crafted and informative site, and a joyful experience. I had decided beforehand to build the tall vertical, and spent today studying Elmer’s plans. I had not, of course, realized that you had chronicled your own efforts, so I was delighted to stumble on it this evening. My boring and lapping experience extends to one previous engine, but I learned quite a lot about the process, the hard way. I’m looking forward to starting!
Hello Brian, Thanks for your kind words – it’s always good to receive feedback, it makes the whole process worthwhile. I was particulalry interested to hear you are about to build Elmers Vertical mill engine. If you feel I can be of any help during the process simply drop me an email somers.john(spam)@start-model-engineering.co.uk – take out the anti-spam bit from my addy. I would be very interested to receive progress photos during your build and maybe a video at the end !
John