What have I learnt building the Stuart D10

[geoff5269]

I have built several ambitious model engines over the last few years so I thought that building a basic Stuart would be plain sailing and maybe it would be close to perfect,
but it can still be a challenge and there are still lessons to be learnt so what went wrong.
While machining the base with a nice new carbide end mill I found the cutter digging deeper and deeper before I realised it was being pulled out of the collet, and I lost some height in the piece. also this dig in had shifted the vice a little and this showed up in a later operation, and I think both of these happened because of the very smooth and hard surfaces that are being clamped don't grip as well.  So I must take more care next time.
The next major bloomer was when I had machined the crankshaft in one piece, a process I had avoided before but  thought I had better try it and it seemed to go well, I turned the crank journals with a parting tool I had sharpened in the tool post so that it was square and sharp to the corners, but after finishing the work I moved the cutter aside and then the eccentric work came round and hit the tool and was bent out of shape before I could even try it out. I couldn't believe I had been so stupid. So I had to make another with built up parts but that seemed to take longer to make.
When you come to inserting the piston with it's packing it can be quite a squeeze to get it in so I made a tapered ring I can slide on the piston while it's held in the vice and then transfer that to the cylinder and it pushes in without any poking around with a screwdriver.   I hope this helpful to someone.
I'm in the painting stage right now so hope to finish soon.
Geoff

[b.lindsey]

Despite the mishaps Geoff, the final result came out looking very nice!!  Well done 

Bill

[Jim Nic]

Is that all that went wrong??   You were lucky!  (Spoken in a Monty Python Yorkshire accent  )
Jim

[Chipswitheverything]

Pleased to see the near finished engine Geoff, it's looking nice.  I'm mucking around with two Stuart No 10's at the moment, when the workshop isn't too freezing. As I think I mentioned before, just because the 10 is supposed to be small and simple, it doesn't mean that one can leave the thinking cap off! I've not been greatly helped by a short length of 5/32" dia stainless, for the piston rod,  that Stuart T supplied with my kit 45 years ago, which was mysteriously about 2.5 out of round, and not absolutely straight either...!   Dave

[Jasonb]

Looking good so far.

May not be the jaws as most vice jaws are hardened, if you were holding the casting then it is unlikely to be an even surface so the contact area will be a lot smaller, a piece of aluminium or even paper will increase the contact area and give a better grip.

[geoff5269]

Thanks for the replies,
I have decided to remake the cylinder covers in stainless 303 hoping it will look better, so I got a length of 38mm round and when it came to clamping it in my 100mm chuck I realised that with the jaws that far open there is only 1 tooth of the jaws engaging with the scroll which can't be good.
so I looked at the 4 jaw independent and found there are plenty of teeth engaged at this size I will just have to take time to centre the work.
This metal turned ok with a good finish but parting off such a lump was a no go, so I had to hand saw off the slice and then use soft jaws to hold it the other way round.
Geoff

[geoff5269]

I have finally finished after a couple of attempts at painting and thought I would show the results. There are a few things I would do differently next time so I have ordered a 10V and added the reverse gear which I haven't done before and will try out some new techniques on this. I do like 2 cylinder engines as they start up so easily but I thought I better build something slightly different. Here is a picture and video.<a href="https://www.youtube.com/watch?v=bmzRXWTFpa0" target="_blank">http://www.youtube.com/watch?v=bmzRXWTFpa0</a>
Geoff

[Gas_mantle]

A great looker and a great runner Geoff.

Well done 

[Jim Nic]

A very smart result Geoff and a good runner too. 
Jim

[vcutajar]

Congratulations on a fine runner Geoff.

Vince

[zeeprogrammer]

Seems you learned to make a great runner.
Looks beautiful too!

 

[b.lindsey]

Very nice Geoff. I like the paint job too!!!

Bill

[Chipswitheverything]

A lovely example of the attractive Double 10, Geoff, runs beautifully and looks great, what a nice project!     Dave

[ShopShoe]

That turned out well. Everyone already said it all.

Thank You for posting.

ShopShoe