Stay updated with breaking news from Model Engineer Workshop. Get real-time updates on events, politics, business, and more. Visit us for reliable news and exclusive interviews.
Do you want to contact the Model Engineer and Model Engineers' Workshop team? You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues. Click THIS LINK for full contact details. For subscription issues please see THIS LINK. Digital Back Issues
John, There are abrasives and abrasives, Use depends on the duty. Look up the Mhos scale. Talc is not particularly abrasive, but diamond will scratch everything else. The Mhos scale refers mainly to minerals, but put simply one requires a harder material to abrade any object. The mild corrosion on tooling will have a different hardness and so may well be abraded by a mineral which will not abrade the steel. It’s why scotchbrite is used to polish up a finish rather than grinding away the base metal. On top of that there are different grades of any particular abrasive. Coarse which leav...
I've had a CK Parallel-Grip Perfect for many years which does have true parallel jaw movement but only a sliding sleeve to set size relying on friction to hold it in place. Grip is decent but not as good as the real thing. Appears to be discontinued. The Stahlwille 65622250 in the misterworker link from DC31k has the same pivot geometry so should be properly parallel. Geodore do a similar one as type 137 P with, apparently the same pivot arrangment. Looks to be a bit more expensive than the Stahlwille. The one in the Cromwell link isn't parallel grip. The general give-away for parallel action...
Fastenings are not so difficult. Most won't be far off the 3.5 / 5 ratio, though you'd probably want to use screws with size-smaller heads in many areas for appearance or accessibility - a spanner takes up a lot of room! A rough guide to the right area is to assess the nut and bolt sizes in full size, and bear in mind they had to be manipulated by blokes with spanners. Looking at preserved machinery, a lot of the ordinary fastenings were no more than perhaps 3/4 diameter; much above an inch was usually for major, fitted bolts holding parts like cylinders to frames; or specials on marine-engi...
When I got a Myford quick release collet chuck for my S7 Mk1 it also came missing the clevis, it's a simple thing to make assuming you have access to a milling machine, if not you could even hacksaw the clevis cutout, no particular accuracy is required, it only works for a few seconds to open or close the collet, the rest of the time it just sits there, for the clevis pin itself I just drop a m6 bolt through the hole. I've got to go out now but if you want I'll try and put up a photo of it later and list some sizes, but I've no idea what you have exactly with the ML7 attachment so no guarante...