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| spuddevans:
I have finally got round to making a start on my next ( Yep, I've caught it... :proj: ) project, and while tempted to do a Rocking engine, I had to stick with with my initial plan of building Bog's Paddleducks engine. So I had previously got some materials gathered for this build, and not having any cast iron at all, but having a brass block that was itching to be reduced to a nice cylinder-shaped block, I decided to use brass for the cylinder. Here is the raw brass block, the other dimensions are 25mm thick and 50mm high. I then used my very expensive marking dye system and used my vernier caliper to mark out a rough shape to then transfer to my very expensive bandsaw (my right arm :lol: ) So I next ground up a tiny toolsteel for my tiny flycutter as per the Bogstandard curved profile that I read about on a thread here somewhere. This is my second attempt at grinding the curved shaped flycutter, I have a larger flycutter that doesnt cut as well as this latest attempt, practice I guess ::) So with this newly ground up tool I am totally impressed with it. The finish on brass is soo silky smooth!!! Compare it to using a end-mill and there is just no contest. I also learnt that my X2's Z axis is made out of a very tough but flexible form of spagetti. I am intending on re-inforcing the upright column, but in the meantime I have to be mindful of taking lighter cuts. I have an even smaller flycutter, they're so dinky. By the way, is there an accepted method of working out what speed to set the mill at for flycutting? :scratch: ( the smaller flycutter seemed happy to run faster) So after squaring and sizing the 4 sides I then squared off the 2 ends with a 4-flute mill. It's amazing how the little brass chippings/shavings get everywhere (especially down the neck of my teeshirt, and they are pretty hot too :bugeye: ) My workbench was (and still is) covered with a golden snowstorm. I then had to smooth the 2 ends with some 360grit wet+dry placed on a granite plate to try and get them to match the smooth flycutter-ed surfaces. And here it is, the first part made to size (well within 0.02mm on 2 dimensions and dead on the 3rd :thumbup:) That's all I got done today, not much to see so far, but it's good to be back on an engine project and I cant wait to get back into the workshop to crack on with it. Tim Edit: If you want to see larger versions of the pictures of this build click here |
| Darren:
Well done Tim.... :clap: I'm itching to get back to my paddleduck build, but at the mo I have too much else on and no machines running...... :( I'm moving my workshop as well as continuing to build the garage....oh hum, won't be long and I'll be cutting some swarf soon enough..... :) You've taken on quite a challenge, this engine so far has taught me a quite a bit so far ....and very enjoyable it is too.. I shall be watching you closely to pick up any tips..... :thumbup: |
| bogstandard:
Seems like you have made a good start there Tim, best of luck following my ramblings. Now there have been a few of these engines made, I can relax a little. At one time I was being innundated with emails for help where someone was having a problem, but now, people who have more up to date info can step in and help you as well if you need it. Just go along nice and steady, do the measure twice, cut once routine, and don't worry too much if you haven't got the right materials, as long as it looks and feels strong enough to do the job, use it. You will find very few tolerances, any that are critical are well signposted. Just use the make it to fit rule, if you machine a slot a little too large, see if you can get away with fitting a larger piece into it. Lots of times, you will find it will save you having to make a new part. With regards to the flycutter, as long as you have ground the faces as shown with the reliefs required, you should find that you will get a surface finish like a mirror with a finishing cut of about 5 thou on your particular machine. I have a heavy built machine and can take off 100 thou (2.5mm) in one go, and all I do is listen to the machine, it will tell you if it is struggling. I would suggest on yours for a max cut on non ferrous, about 20 thou (0.5mm) and on say a 3" total tip swing, try around 400 to 500 RPM and see how you get on. A lot of using a flycutter like this is feed rather than speed. The slower feed you go, the better the cut and finish. Bogs |
| spuddevans:
--- Quote from: bogstandard on July 28, 2009, 05:39:22 PM ---With regards to the flycutter, as long as you have ground the faces as shown with the reliefs required, you should find that you will get a surface finish like a mirror with a finishing cut of about 5 thou on your particular machine. I have a heavy built machine and can take off 100 thou (2.5mm) in one go, and all I do is listen to the machine, it will tell you if it is struggling. I would suggest on yours for a max cut on non ferrous, about 20 thou (0.5mm) and on say a 3" total tip swing, try around 400 to 500 RPM and see how you get on. A lot of using a flycutter like this is feed rather than speed. The slower feed you go, the better the cut and finish. --- End quote --- Thanks Bogs, I have tried to grind the flycutter as per your C-o-C and photos, This second attempt seems to be better than my 1st go. I dont know if it is because of the flexibility of my little mill, but I seem to get a slightly better looking cut feeding from right to left, and I also note that I need to tram as the cutter is only leaving marks in one direction. I found that I was removing about 0.3-0.4mm per pass, the mill didnt seem to mind that. I guess having a power feed would really help on getting a really good surface finish.( sigh, yet another mod to add to the ever-growing list) The flycutter tool tip swing is about 2" using this little flycutter. I hope to get out to the workshop this afternoon to do a little more, (puts on best tv announcers voice) "Stay tuned for updates" Tim |
| bogstandard:
Tim, It is that slightly out of tram that you can use to your advantage with a flycutter. 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 |
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