Upshur Twin

[raspii]

Hi Guys,

Here is the story of my Upshur twin so far, this is my first full construction of an engine and massive learning curve all rolled into one. I'm sure along the way as i tell the story you will be rubbing your head saying "no Pat, not that way" and then hopefully by the end of it i will be doing it the correct way. If not i'm open to any suggestions please

The plans were sourced from my favourite publication model engine builder magazine out of issues 7 and 8. The only head scratcher i have had with the plans is changing from imperial to metric, but other than that so far it has been smooth sailing.

My tooling of choice is a Sieg C2 lathe which i have had for about 12 years now, and a Sieg X2 mill which i have had for two years now. When i started this engine i had just purchased the mill and had watched a lot of video's, but only had the pleasure of working with a mill once before. So it was a steep learning curve and lots of 'practicing" before i could get stuff right. I also recently fitted some basic DRO's onto the mill to assist which cost me just over $100AUD

Attached is the picture of my current setup, sorry for the mess as i was not intending for anyone else to see this pictures, I had taken this picture after installing a basic extraction system which is currently folded down for both the lathe and mill, but i fold them both up and only fold down what i need, when i need it. This was being used when i was cutting steels that were very smoky, originally i have been using things like WD40 and similar products, while recently i have changed to using a water based cutting fluid which is a lot nicer to work with and a lot less smelly and smoky. (Ahh if only i had known back then what i know now....)

 

[raspii]

If you are familiar with then engine you will know it's built like an old land cruiser, all flat panels. This i'm sure would be no trouble at all for the experienced engineer, but for myself was a little harder than i had hoped, but a great learning experience getting used to my new mill.

Lots of practice cuts, some more tramming and then finally the parts were starting to look square!

Finally some aluminium which looks all nice and square, which was then quickly followed by all the other pieces,

The other two sides are made of mild steel rather than aluminium which support the crank case. This was a little more interesting as it was harder to machine and i had also stupidly purchased metal that was too think for the job!

This was the most embarrassing part as it took so so long to get them right, all experience i know, but boy did it take a while. I ended up bolting a long piece to the mill bed and bolting it in several places with enough space between each bolt for one side of the engine, then milling them down with a indexed end mill to finally get them to the right thickness and finish while still being level. Never again!

Sorry i don't have any pictures of that part, i think it's a repressed memory now!!

So finally we have a base out of aluminium, top out of aluminium, two sides out of aluminium and 2 mild steel sides to the right thickness and also square ! Woohoo!

A little bit of drilling and tapping with the aid of my handy wobbler centre finder and dro's , some drill and reaming and finally some boring and we have it now all bolted together and looking half like it can be something

Then a good spray of lanolin spray to keep it all clean and free of rust and onto the next part, which leads me onto my next question.......

This model in the past has been presented with all nice shiny pieces which is a combination of aluminium and mild steel from what i can gather. Has anyone ever used a nickel plating solution to keep the metal looking nice and shiny while preventing corrosion while running and on display. I'm thinking of either painting it or nickel plating, with the plating option making it look really shiny and authentic. Just a thought and still some time to go before i have to decide, but anything that stops rust is good in my book. I have been watching some instructables.com and youtube video's and it doesn't look too hard to do it at home with the right gear and a bit of time and patience.

 

[raspii]

Next step has been the cylinder walls, this was a challenging task, a little more than normal as what i didn't realise at the time was my 10 year old Chinese lathe had some very worn bearings in it and no matter what i tried i always got terrible chatter.

I had also made some changes to the original plans (like it seems many others have also done) as the instructions are to weld the cylinder liner onto the base, not having the knowledge to do this or the right tools i chose to make the cooling fins longer right down to the base so i can bolt the whole assembly together.

After two days of solid machining avoiding chatter, i finally got to turning down to the final diameter area and with one final slight turn of the handle had my piece fall in two right in front of my eyes. As i hadn't drawn the new plans in cad, but just sketched on a bit of paper one digit of my maths was wrong and the wall thickness of 1.5mm was really .1mm

I then when inside, got some composure back and immediately drew the new part up on cad with the correct dimensions, then i went back to the garage and 3d printed the part to double check that all the measurements were correct. Thankfully it all fitted like a glove and i started again to make the new cylinder.

Two days later we had a cylinder, what a great feeling when you part that off the lathe and hold it in your hand!

A short time after finishing the cylinder i also made the cylinder liner out of mild steel, my intention is to use mild steel for the liner, 6061 for the pistons and cast iron piston rings. Please someone let me know if this isn't going to work now so i can avoid heartbreak later.

A short time after making the cylinder liner i was working on the second liner and managed to break one of the plastic gears in the headstock, realising i would have some spare time before the gears would arrive i also ripped apart the lathe and with some assistance from a friend fitted new bearings into the headstock.

The finish i am getting now is so much better it's almost a shame as i want to now go back and remake all the previous parts with markings on them obviously caused by the worn bearings. If you have one of these lathes and getting a poor finish changing the bearings is well worth the effort!

I then proceeded to make the second cylinder wall and liner, what took me two days before with the old bearings and lots of chatter, took me two and a half hours and so little noise i could hear the radio! What a great day!

 

[raspii]

Finally it's starting to take shape,

After trying to machine a crankshaft from the solid i very quickly retreated to the build up method and inspired by TinkerJohn off youtube i have been machining like mad small pieces to get it done. Also invested in a bottle of loctite 620 to secure it all together, Final stage of this part to do tomorrow is drill 2mm holes through each of the joins and glue drill rod pins in the assembly to really make sure it stays in place.

 

[raspii]

Finish of the crankcase is not bad, looks terrible in the pictures as it's covered in lube to make sure the metal pieces don't rust.

Worked out a little trick to cut small items with the milling machine, collet in a collet.

 

[gg89220]

hello
I also started this engine

 

[raspii]

Con rods now all drilled and reamed to size, just need to add the bushes and contour.

Pistons being milled out inside

Pins now glued in the crankshaft.

 

[Brian Rupnow]

Mild steel is a very poor choice for cylinder liners. Conventional wisdom is to make them from cast iron. Cast iron has self lubricating properties do to the metallurgical properties. Mild steel will gall very quickly.

 

[deeferdog]

I think your work is great and I have been following this with interest. My first mill was a Sieg X2 and I sure learned a lot on it. My efforts at built up crankshafts always seemed to leave a bit to be desired and am now a fan of machining from solid. At least they run true. Thanks for the time spent in posting this. Cheers, Peter.

 

[raspii]

Mild steel is a very poor choice for cylinder liners. Conventional wisdom is to make them from cast iron. Cast iron has self lubricating properties do to the metallurgical properties. Mild steel will gall very quickly.

Thanks for the tip Brian, I will make again out of cast iron. :thumbup:

From Pat

 

[raspii]

I think your work is great and I have been following this with interest. My first mill was a Sieg X2 and I sure learned a lot on it. My efforts at built up crankshafts always seemed to leave a bit to be desired and am now a fan of machining from solid. At least they run true. Thanks for the time spent in posting this. Cheers, Peter.

Hi Peter,

Thanks for your message, it really inspires me to keep going along and keep building, as you have read i hit a lot of snags earlier on and it really put a bit of a dampener on the build, but as i have been on holidays recently as well as purchased a bigger lathe it has really given me another lease on life to keep going, the small Sieg C2 lathe just wouldn't cut it sometimes, (pun intended) although it's been cold in Victoria i have kept on building and am amazing myself at how much i have been able to complete. Fingers crossed within the next 12 months we will have a runner!

I am still a little weary about a built up crankshaft i must admit and hopefully mine does alright, If this one doesn't work it has certainly been a very long and educational process at least. The best thing i did while making the crankshaft was used cobalt drill bits when drilling the 2mm holes for the pins to go through, i could just see a normal drill bit snapping in there and me getting very upset after all that work.

All the best mate,

From Pat

 

[Cogsy]

Thanks for the tip Brian, I will make again out of cast iron. :thumbup:

I can't guarantee the mild steel will be ok but I can teel you that Steve Huck's Demon V8 and Peewee V4 both use 12L14 steel cylinders with cast iron rings and have many hours of running on them with no issues, so there is a possibility mild steel will be ok. As you've already made them I'd be tempted to use them and see what happens myself. Really the worst that can happen is having to remake them at some point anyway.

 

[raspii]

I can't guarantee the mild steel will be ok but I can teel you that Steve Huck's Demon V8 and Peewee V4 both use 12L14 steel cylinders with cast iron rings and have many hours of running on them with no issues, so there is a possibility mild steel will be ok. As you've already made them I'd be tempted to use them and see what happens myself. Really the worst that can happen is having to remake them at some point anyway.

Thanks for the tip Al, That was actually what i had made them out of, if my googling is correct that's what they also call bright mild steel i hope.

Thanks again, will keep you posted

 

[WOB]

Thanks for the tip Brian, I will make again out of cast iron. :thumbup:

From Pat

According to the dwgs, this engine used cast-iron ringed aluminum pistons. They work perfectly well in mild steel cylinders. 12L14 machines nicely and is a very good choice. I have built 3 aero engines including 1 cylinder and 4 cylinder boxer glow-plug and a 9 cylinder spark radial using those materials and they run beautifully.

RWO

 

[raspii]

A little more done this weekend

 

[raspii]

Bit more progress to date, Sorry it has been a while in between posts.

I had that terrible feeling when i spent two weeks almost solid and made so many parts that i was up to start trial assembling the engine, only to find the built up crankshaft is no good and i have to start again, (sigh) but hoping to get back into it in the next week or two , so close yet so far... everything else went pretty well considering it's a first attempt.

 

[raspii]

This is all i have done to date,
Just need to finish the heads,
new crankshaft
ignition
put together cam shaft and we will be so so close!

 

[tornitore45]

There is mild steel and than there is mild steel. Usually mild steel is just plain very low carbon <0.2% it machine with a surface finish similar to a cat tongue.

Leaded 10L14 is mild 0.14% C but the lead makes it "Slippery" and easy to machine. The finish is like a mirror. The lead content makes is somewhat self lubricating, for that reason is an acceptable substitution for cast iron in model engine that are run only sort time.

 

[deeferdog]

Hi Pat, I've followed your build with interest and really like the way you work, much more organised than my usual muddle. I don't think the steel cylinders are going to give you too much trouble, Cogsy's advice seems pretty good to me. Cheers, Peter.

 

[raspii]

New Crank Shaft, the original one i did isn't quite straight which is a little bit of an issue. Have taken my time with this one and trammed the mill very well before i started. So far so good.

Also glued in spacers to keep it square while the loctite dried, will check it's straight again, and then loctite pin it all together before tapping off the super glued supports.