Member postings for Gareth Jefferson

Please put me right (nicely) if I’m in the wrong forum with this question.

All the squareness comparator designs I’ve seen, mostly on YouTube, have had a curved “bumper” at the front edge of the base. I’ve never seen an explanation of what purpose this serves. Is the radius of the curve critical, and if so why (my maths is about a rusty A level, if that helps.

I’ve done lots of Google searches but to no avail so far.

Either an explanation, or a link to something relevant would be greatly appreciated.

— Gareth.

... not ... fags as in faggots. Engineers can be gay too, probably around 5%, as will be around 5% of readers of our fovorite magazine. Perhaps I should update my photo with a rainbow flag in the background.

–– Gareth.

Edited By Gareth Jefferson on 30/10/2017 18:10:14

Edited By Gareth Jefferson on 30/10/2017 18:10:55

I live in Kent between Ashford and Maidstone. I'm pretty old to be a beginner: 73 in November. I've been putting together a workshop over the last two or three years and it is now up and running, lacking only a surface grinder and a shaper with a motor.

Currently motorizing the Z and X axes of my 1kW Chinese mill and looking for carbide blanks (can't find them anywhere) to use in a Biax scraper.

– Gareth.

Thanks Steve.  I have been trying to find sources for small quantities of carbide stock. Any thoughts???

-- Gareth

Edited By Gareth Jefferson on 18/10/2017 16:48:28

Edited By Gareth Jefferson on 18/10/2017 16:49:37

Thanks for the link. I was previously able to find Biax's site using Google. The part of their site that deals with scraper blades is only in German (a language I don't speak) and anyway contains dimentional data and so on but no prices.

Thanks, anyway, for your help.

-- Gareth.

I recently had a sanity lapse and bought an Biax scraper. These things really hold their value; a decades old Biax costs about the same as an entry level price for a Jones & Shipman surface grinder. My scraper is a model IV/EB. It's so old even google can't or won't release any useful information. I think and hope blades for current versions will fit my machine.

Does any forum member know where I could find Biax blades in the UK? I think you can get them in the States but American postal rates are phenomenal (another area where the Americans could learn from the Chinese). I'm a total newbie, so please let me know if this posting belongs somewhere else.

Since silicon carbide "green" wheels would obviously be hard enough to grind hss, is there any reason why I shouldn't didpense with my aluminium oxide grindstone and use the now free end of my bench grinder for a diamond wheel? I mostly use hss in the lathe and mill but want to start scraping using carbide scrapers. I have a spare bench grinder but bench real estate is running out fast in my small shop.

--- Gareth

Re the "horrible" runout of my Sieg SC4 lathe. It seems my methodology may have been the problem all along . As I mentioned earlier, I measured the runout by using a plunge-type dial indicator on the flange on which chucks are mounted. When I removed the chuck and measured a precision ground test bar terminated with an MT3 taper, and later directly within the mouth of the MT3 opening in the headstock, using a no-name lever-type dial indicator showing 0.01mm per division, I could get no discernible reading at all. With a bejewelled Swiss Baty lever-type indicator reading 0.002mm (2um) per division there was a discernible flicker of the needle of less than one division, so I can confidently say that the runout is probably <0.002mm.

Thank you to all who have helped me with this runout problem. To asnwer XD351's question, I measured the runout using a plunge-type dial indicator mouted on a Noga arm with the indicator tip touching the flange to which the chucks are attached. Currently, runnout is about 0.27mm.

I have a ground parallel bar with an MT3 taper and I'll try measuring that next, but I'm not hopeful. I strip-down is in order, is guess.

-- Gareth

I wonder if anyone here has experience of replacing the headstock bearing/s in the SC4 lathe. Mine has had little use and very low runout when I bouught it, but it has become gruesome. I have not been able to find a dimensioned engineering drawing of this lathe. Before I start dismantelling it and measuring for replacement bearing/s, perhaps someone here could give me some advice. A ling to a proper drawing of the lathe would be expecially helpful.

Gareth.

All your replies have been extremely helpful. I'll go for the MT2 to parallel adapter (rdg do indeed sell them) tho at over £17 they're not cheap. On the other hand every time I remove and replace a chuck, tightening up the bolts *just right* for minimal runout error is a pain.

Thanks guys.

Gareth.

Although a beginner, I plan to make a fairly complex boring head. I have an MT2 bar with a soft workable cylindrical end that I need to cut a tread in.

Question: How do I support the tapered end while I cut a thread on the soft end? Obviously, ramming it into a 3 or 4 jaw chuck would damage the taper.

Any suggestions?

Regards,

Gareth.