25 cc Horizontal Engine

[steamer]

The faceplate is to allow you to balance the part?....I think?

Great looking Crank!

Dave

[Don1966]

There's some serious metal work going on here. Nice crank Roger I like............

  Don

[Roger B]

Dave, the faceplate is just being used as a driving plate (I don't own a separate one). I wanted something a bit more than a bar collet to take the interrupted cutting.

[Roger B]

A bit more work on the crankshaft. It's made of C45K, a bit like EN8, and decided to gouge a bit on the finishing cut of the long end. It will do whilst I build the engine but I will probably make another one.

[philjoe5]

Roger,
I don't know how much at liberty you are to make changes in the plans but since you haven't made the crankshaft bearings and blocks can you take another finishing cut on the crankshaft using a center?

I'm enjoying this WIP.  Your pictures are very useful in following along

Cheers,
Phil

[Roger B]

Phil, I could reduce the size, all it would mean is buying another reamer to suit.
The problem is more that I need to understand what I can do to ensure a good finish without this gouging. The same set up was used on both ends and the tool was lightly ground before starting either end. The short end gouged initially but was then ok. The long end was ok and then gouged. It may be a rigidity problem in which case I will also try some experiments on my Hobbymat.

[Roger B]

Moving on to the cylinder. I bored it out using the lap body as a plug gauge. The piston will be made to fit so the actual size is not too important.

Unfortunately it has ended up a little tapered (the wrong way so when the gauge entered it was over size by around 0.1mm at the other end) so there is a bit of lapping to do.

I am using a coarse paste so it is removing the metal fairly quickly and it is quite easy to feel the parts that are tight and are cutting. The finish at the smaller end is looking really good to my inexperienced eyes 

[Roger B]

Next some work on the flywheel. I wanted to see if it would fit on the Hobbymat? It does, just, 125mm dia 65mm centre height. I initially cleaned up some of the eccentricities on what will be the engine side before I turn it round and fit the taper sleeve. This will be done in the same way as on my vertical engine using two grub screws to clamp and release. I had to replace the quick release toolpost with the original to get the tool angles

The taper sleeve is made from free cutting ms. I initially set the taper to 6° instead of 3° (each division was 2°  :embarrassed: ) but after that it cut nicely. The 1 MT chuck only went to 11mm, but luckily the chuck taper was the same as my 16mm chuck so a swap was possible.

Next step part off and bore the flywheel to suit using the same topslide setting.

[fumopuc]

Hi Roger, it looks like you are happy with your Hobbymat. The casting you have there, looks like the ones I know which are sold by a company from Luxenbourg. Was it O.K., I ask this, because when I have ordered there in the past in their internet-shop, I have got only very poor quality with lots of gas porosity holes in the surface.

[Roger B]

Hi Achim, there are a few differences to get used to however I am very impressed with the Hobbymat compared to my Chinese minilathe. Considering it weighs the same it appears much more rigid (possibly due to the better sliding surfaces) and although technically slightly less powerful the belt reduction rather than a poor electronic speed control means that in practise there is much more torque available.

The flywheel is from RC Machines and to my inexperienced eye (it's the first casting I have machined) it seems to be good quality.

On with the flywheel. I changed back to the q.r. toolpost so I could quickly move the boring bar out of the way for trial fits of the tapered bush. I know how quickly you can go too deep.

[philjoe5]

All you guys doing these taper lok joints are really pushing me into trying it.  Great work Roger and thanks for the photo documentation

Cheers,
Phil

[Roger B]

I hope to finish the taperlok this week end. The first one I made was divided using the 4 jaws on the chuck but this time I think I will mark six divisions around the faceplate and use three screws rather than two. As ever some of it is designed and some is made up as I go along 

[Roger B]

Final stages of the taper bush. The holes were divided by marking round the face plate with dividers set to the radius giving six divisions. The holes were finished on my little Proxxon drill.

Slitting was done using the vertical slide from the Chinese lathe that happened to match some additional holes on the Hobbymat slide.

[Roger B]

Started making the base. I didn't really need to mill the ends of the angle iron, but having a new machine meant that I needed to play. The welding sequence will require some thought to avoid heat distortion.

[philjoe5]

Looking good so far Roger.  Good luck with the welding

Cheers,
Phil