| Gallery, Projects and General > Project Logs |
| Maiwald Makeover....... |
| << < (8/15) > >> |
| Stilldrillin:
I drilled out the cylinder with 7/16" drill, held in a 12mm R8 collet. Didn't think R8 collets would compress willingly, that far..... The 7/16" K&S tube needed it's o/d reducing by a couple of thou. So, I turned a mandrel...... Leaving the o/d a little rough, for grip, stuck it in place using my favourite sleeve retainer....... Will drill through to the displacer chamber tomorrow, when it's cured. Question time now. Re-graphite pistons....... I've never turned a piston, without some oil grooves. Do I still groove a graphite one. Or, leave it plain? :scratch: David D |
| lordedmond:
David leave it plain. and bring to final size with brown paper for emery, cover every thing up inc. yourself it gets everywhere barriers cream on the hands is a good idea with CI I am banished to washing hands in a bucket same with graphite Stuart |
| NickG:
Yep I'd agree leave it plain. I woul personally just turn it to size taking very small cuts will keep it parallel you'll find a very slightly tight fit, not tight but not fall through on it's own loose, will quickly wear it's way into the perfect fit after a few rotations of the crank. No need to lap or any such daft things it will create it's own perfectly smooth finish providing it's not as rough as a badger's arse. No need to cover stuff up, it's a good lubricant for machine, messy though! |
| Stilldrillin:
Well....... I managed a workshop hour, this afternoon. Pity it wasn't more productive......... :palm: I was trying to emulate the original piston, only longer........ Guess I'll have to make a clevis, down inside the skirt. Held in with an M3 screw from 'tother end. This stirring stick graphite is a lot coarser than I imagined it would be! :scratch: David D |
| NickG:
Hi David, shame about that - it does look coarser than the stuff I used but reckon it'll still work - it looks sort of metallic? I've never tried threading it, do you need to? Also, do you need to mill the slot for the rod right through it? I left some material around edge on mine for strength and made the gudgeon pin a push fit in the graphite and a sliding fit in the rod - then you can assemble with light pressure and if the pin is slightly shorter than the dia. of the piston it will never move, the pin is stationary. see attached for how I do mine, just a thought. Nick |
| Navigation |
| Message Index |
| Next page |
| Previous page |