Another Paddleducks build log

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kvom:
Since the block has a large number of holes to drill/bore/thread/deburr, you might want to wait until it runs before worrying about the finish.

Myself, I use the flycutter only for very fine cuts after an endmill has made the dimensions close and the surface flat. Having a table feed makes it a lot easier, as you say.

spuddevans:

--- Quote from: bogstandard on July 29, 2009, 03:47:31 AM ---Whichever way it is that does what is called the back cut, taking a tiny amount off, that is the way you should use for final finishing. It gives you two bites at it.
Feed it so that the first cut is being done, but when the trailing edge that does the extra bit of cutting gets onto the face, slow down, and very gently carry on feeding. that back face is only taking off a minute amount, less cut than you could ever hope to put on with the handles, then just carry on until you have done the full cut. I find a little squirt of WD40, no matter what the material, really helps with getting that mirror finish.
As you have said, having a rubber machine doesn't help, but with a little practice on using the fly cutter, your finishes will improve dramatically.

Bogs

--- End quote ---

I seem to remember you saying that you used a slight out-of-tram mill as an advantage in finishing, thanks for reminding me of that.

Thanks Kvom for the advice to wait for the final finishing til after all the holes are bored, my excitement gets to me and I forget that I've got many more steps to do on the main block.

I got some time in the workshop today, and started out by Tramming my mill. A frustrating exercise as when you think it is in tram and then tighten the big nut holding the column in place, the act of tightening will throw the mill out of tram again. :bang:

After tramming the mill I started marking up the main block for the cylinder holes, then clamped the block in the vice on top of some 1/2" parallels. I then used the edge finder to locate the hole centres as accurately as possible, and then centre drilled them. Working out the graduations on the mills handwheels it worked out at 18 full turns to traverse from the center of one hole to the center of the other.

I then drilled and then opened out the holes starting with a 4mm drill, then 6mm, 7mm, 8mm, 8.5mm 8.7mm, 8.8mm, 8.9mm and then finally reamed the bores to 9mm. ( I would have drilled/reamed them 10mm but I dont have a 10mm reamer, but I do have a 9mm reamer so I figured that making the bores slightly smaller would not make a big difference. I'll just make the pistons to match )

And this is the end result.

I then turned (groan) to making the Top-Caps. I chucked up a length of some unknown steel ( to contrast with the brass ) in my 4jaw ( my 3jaw self-centering has too small a bore to allow the length to go into the headstock in order to use it without cutting it down ) Turned a section down to 18mm diameter, put a 9mm spigot on to fit the bore, then parted it off, and then repeated for the other.

Then I mounted my ER32 chuck, the 18mm collet and mounted the topcap in it to turn the "Top" side. The 2nd one turned out better, practice makes perfect better.

Here's what they look like mounted on the block.

That's all for today, "Tune in next time for more of the same"

Tim

sbwhart:
Coming along nicely Tim

:thumbup: :clap:

Have fun

Stew

Stefan Pynappels:
Looking good Tim. Glad you got the fly cutter working, look forward to seeing it at work.

Hope to be over for a little while on Friday, maybe get some more of my project done, you can explain the niceties of this engine to me then.

Stefan.

spuddevans:
Thanks Stew, it's nice to be back making an engine again.

--- Quote from: spynappels on July 29, 2009, 02:30:42 PM ---Hope to be over for a little while on Friday, maybe get some more of my project done, you can explain the niceties of this engine to me then.

--- End quote ---

That sounds good Stefan, we should get your project finished ( well that's put a curse on it now :hammer: )

Tim

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