| Gallery, Projects and General > Project Logs |
| Stuart 10V Build Log |
| << < (5/27) > >> |
| DMIOM:
--- Quote from: craynerd on October 01, 2010, 10:20:13 PM ---...... Now the feet are machined, I made some clamps so that they can slot around the casting centre of each foot. ....... So the next thing is going to be boring it out but it got late and I thought I`d leave it until tomorrow and see what you guys thought of my setup first... --- End quote --- Chris, just an observation from a non-engine-builder - in your last photo: It looks like the profiled (brass?) straps are bending - maybe something more robust could be useful? Dave |
| raynerd:
Thanks again for your comments.... Nick - I have to admit that when I did the feet again, it wasn`t a perfectly even cut at first so clearly although my original method cut the feet and top parallel, it didn`t cut the feet at 90deg to the bore. That being said, it was only a whisper out! My understanding is that now the feet are square to the bore, I bore and face the top surface and then use the same method for the feet again ensure the feet are parallel to the top cylinder mount surface. Just curious....if the cylinder mounting surface has been machined with the feet flat on the backplate - won`t the feet be parallel to the top surface anyway?? Regarding the bearing holes. I had skimmed the bottom first and then skimmed the top using the bottom as reference - I didn`t show this in my photos. I did think about this when I drilled for the bearings so I purposely mounted with the bottom face down...!? Since the bearings are screwed into position, there is apparently some movement in these anyway so I believe this isn`t too critical. Infact I think in the recent ME article, the writer explains that you can file the bearings holes by hand and do them slightly over size so that you can actually have some flexibility and adjustment in these. Dave - the clamps are bending a little bit but they are a good thickness! - which suggests a little bit of heavy handedness perhaps. They are holding well and although I did consider making them out of steel (which I have) I choose brass so as not too over tighten and break the castings. Would others re-make these before going ahead and boring out? Last thing I want is the Standard slipping. I do feel it is centred well and the clamps are really holding down on the feet. Thanks again for your ideas. |
| kwackers:
Looks a lot better to me Chris! Regards the bearings, you can file the profile out. The only important part of them is the mating surface that they bolt onto (the actual dip is purely cosmetic). The skim you did on the mill is spot on since the four surfaces will all be planar (the two bearing mounts and the two standard mounts). Regards the brass hold-downs, I'd remake these in steel. They shouldn't bend! The castings will take an immense amount of pressure - providing they're flat on the faceplate. With regards holding stuff in place you ideally should apply pressure evenly to the entire foot of the casting. What you've got is simply holding the corner, if you think about it this offers very little in terms of 'friction' and it would be fairly easy to break the edge off if the casting was pushed to the side. So what you've got is ideal - but, remake it in steel, it should then be packed up at the other end the same height as the casting and there should be no bend when you tighten it up. Other than that looking good! |
| madjackghengis:
Chris, with regard to clamping iron castings one cannot clamp too hard, or too solid, iron having a very high compression strength. You've got about half again the length of column away from the faceplate as width of hold down, so the side pressure as you bore will be multiplied by about one and a half, so you really want those feet down solid. Steel is a definite, brass tends to have no spring in it at all, especially when it has already been taken past rebound, as the bending shows. If there is any question about alignment once you've clamped it down solid, and bored and faced the column, take a piece of round stock in your chuck, turn it to a push fit on the bored out guide, and hold it in place much as you did to face off the feet the first time, and reface them, taking as little off as possible, and still get the whole of the feet surfaced, and everything will be square and accurate. This particular part is the most critical of alignments for this form of engine and sets up all the other points of alignment, so getting this off a bit, will throw everything else off. The good news is the setup is right, just the wrong material for the clamps, and cast iron when right, machines very nicely. That is a very nice project to choose, and I'm looking forward to seeing the whole of the build, and eventually seeing it run. :bugeye: mad jack |
| DMIOM:
and another tiny thing Chris - the repair-straps you've used for packing don't look to be anchored - my preference is that anything like that should have something other than just friction holding it in place - just imagine if that was spat out, with its relatively flat profile, when you were in front of it ....... (could be like some medieval weapon!) Dave |
| Navigation |
| Message Index |
| Next page |
| Previous page |