Engines > Your Own Design
Scotch All Round
PaulR:
--- Quote from: wagnmkr on February 24, 2025, 11:17:12 AM ---Ya had me at "Scotch" :)
--- End quote ---
Best lay off that while in the workshop :DrinkPint:
PaulR:
Did just a little more today, finished turning down the ends of the cross members, now they just need the through holes drilling. Also drilled and reamed the holes for the bearings after the photo was taken. Started making the bearings but ran into an issue with a blunt drill bit which, when went badly wrong when I tried to sharpen it on one of those bench-top multipurpose grinders. Don't think I can rescue it by hand so will need to order another.
PaulR:
Chopped the valve chests (well just open ended cylinders) down to size and used that side of the frame to mark out the holes for the steam pipes (cross members) and the securing screw on one of them. The projections on the end of the pipes go inside the valve cylinders which stops them rotating so only one securing screw is needed. Hopefully :Lol:
Really should have done something to protect the work in the 4 jaw but repeatedly having to take the part out to check its length was tedious enough, I don't trust the backlash in the top slide to rely on that for measurement when facing off a mm or so in 1/8mm increments.
MJM460:
Hi Paul, I find the trouble with removing the work from the chuck is that you then lose any reference distance to the cutter, much better to leave it in place.
I first note the measurement, then mount the workpiece in the chuck then measure from the face to be cut to a suitable reference such as the face of the chuck, (not the face of the jaws) with calipers using the depth function or preferably a depth micrometer. Then wind the top slide away from the cut two or three turns and approach the cut from there. After the first cut to make a good surface for measurement, you can re measure to the chuck face to calculate how deep you have cut.
The other trick is to set up a dial gauge against a face of the top slide where it will be not too much in the way, set it to zero and use that to measure how fat you move the top slide. It’s a good compromise for lengths within the dial gauge range until you can add a digital scale or DRO.
I am sure more experienced members will have even better ideas, but the dial gauge trick works for me.
Looking forward with others to seeing the arrangement develop.
MJM460
PaulR:
--- Quote from: MJM460 on February 26, 2025, 04:51:04 AM ---I first note the measurement, then mount the workpiece in the chuck then measure from the face to be cut to a suitable reference such as the face of the chuck, (not the face of the jaws) with calipers using the depth function or preferably a depth micrometer. Then wind the top slide away from the cut two or three turns and approach the cut from there. After the first cut to make a good surface for measurement, you can re measure to the chuck face to calculate how deep you have cut.
The other trick is to set up a dial gauge against a face of the top slide where it will be not too much in the way, set it to zero and use that to measure how fat you move the top slide. It’s a good compromise for lengths within the dial gauge range until you can add a digital scale or DRO.
--- End quote ---
Thanks for these tips. The first one sounds like a good idea and more accurate than using the scale on the topslide - I'll give it a try next time :D I don't think the second idea is a 'goer' for me as it's already very cramped in the working area. I managed to get both pieces down to within 0.04mm of the target, it just took much longer than necessary using my hokey cokey method!
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version