Member postings for Ro

Haha, yeah, that's what I found. With the state of my scroll, I have no measurable runout at the diameter that I trued my jaws at, but if I go larger or smaller, the runout returns!

ro

Hi Dave, I've literally just had the same issue. Some very helpful folk here (including Hopper) helped me out with loads of advice: here's the thread

ro

Hi Chris, I meant to type 406 instead of 460!

the main reason I use it is because I have loads of it around from trials I have done for work. It’s really strong and of such low viscosity that it doesn’t seem to affect alignment at all.

in reality though, any low viscosity cyanoacrylate should work just fine, and I have used the pound store variety in a pinch before - although as I didn’t trust it’s strength I limited the DOC.

don’t forget about accelerator as well. A quick spray round the outside will ensure that you don’t have any uncured glue left to fly off at you.

Cool, thanks for the advice all. I’ll try to remember not to over tighten that screw!

For now, I’ll just keep a 0.1mm shim close by until I get round to either the wide guide conversion or trying to scrape in the current guiding surface.

I quite often use Loctite 460 to fixture work on the lathe or the CNC router. I normally clean each side with acetone and 2000 grit wet&dry. This works really well and I have no problems with adhesion - just used this method to attach a 5 inch steel plate to the faceplate for facing.

Where lighter cuts are being taken, I quite often will add a layer of masking tape to one side (or both) before applying superglue - to make it easier to remove.

As Jason says, don't apply it in rings, unless you have grooves in your faceplate/mandrel to allow the air out.

ro

Hi Hopper,

Thanks for the info - you were absolutely right! The guiding surface was warn convex, I can't believe I didn't check it when I had it apart before.

I have done the cuts that I needed to do with a 0.1mm shim in between the rear of the guiding surface and the bed, and the gibs tightened up. This has given be a perfectly flat cut.

Luckily my lathe is pre-1972 (albeit with a 1990's bed) so it does have the "narrow guide". I'll order up some 1/16" GFS and see if I can do a wide guide conversion.

Any ideas on the best way to attach the GFS to the rear shear?

Thanks again - I can't believe you were able to diagnose the issue without seeing it!

ro

Thanks Nick. that's an interesting read. you say it could be a badly adjusted saddle, am I right in thinking that the only adjustment I have is the gib strip? I have tried the cuts with the gib at "normal" settings, and with all the screws locking it tight, but still have the same issues.

Hi NDIY, I turned the test bar just held in the 3 jaw, no tail support (just very light cuts ).

Saddle is locked (and, as above I've tried locking it using the gib adjustments too), and I've tried it with a freshly honed HSS tool and a brand new CCGT insert, at cut depths ranging from 5 thou to 0.5 though - same results every time.

Thank you both for your suggestions!

ro

Hi, I'm trying to face off a 5 inch steel disc on the faceplate of my Super 7, but the facing cut is producing a convex surface.

As you can hopefully see in the picture above, if I hold a parallel across the face, flush to one side I get a gap on the other side. Using feeler gauges I have measured this gap to be approx. 0.4mm.

I have checked this with rulers and other parallels, it is not he parallel at fault.

Holding a parallel in the 3 jaw chuck against the face of the chuck and running a DTI against it as I move the cross slide shows that as the tool moves from the edge of the chuck the the centre, the tool moves out by 0.2mm. This feels consistent with the facing results above. In case the face of the 3 jaw was not flat, I span the chuck round by 180 degrees and took the measurement again - exactly the same result.

I have stripped down the cross slide and saddle, cleaned out everything and reassembled it no no avail.

I thought it might me the head out of alignment with the bed, so I turned up a test. bar in the 3 jaw to see if it produced a taper. It was out by 1.5 thou over 6 inches, so I'm pretty sure the headstock is aligned.

Please help! I'm running out of ideas as to what could be wrong!

thanks

ro

Edited By Ro on 18/07/2020 10:24:45

Have you tried using Chrome on the iPad? I can access all the older magazines using that on my iPad and Mac, whereas Safari gives me the same error.

ro

Edited By Ro on 15/07/2020 21:24:27

Hi Mark,

you can replace the board, although you may be shocked at the price!

something like this SHOULD work (worth checking compatability before ordering though):

**LINK**

I did this the first time my controller broke, but after it went pop for the second time, I replaced it with a generic speed controller for about 20 quid from ebay. Worked fine for about 5 years until I upgraded my lathe.

if you want to go down this route, look for "220v DC motor controller", but be warned, it's not a straight replacement, and if you want the reversing switch and emergency stop to work, you'll have to figure the wiring out.

Quite a saving though.

ro

Edited By Ro on 15/07/2020 20:29:27

Well, it feels like I'm finally getting somewhere with this.

Spotted the holes through the cheeks and into the standard, drilled and tapped M5

Put everything together and it all fitted first time! The slide has a nice, sliding fit on the standard.

The only issue I had was that the hole in the file holder. wasn't perfectly square to the sides of the file holder. After a bit of filing and bluing/scraping I was rewarded with a lovely alignment between the.top of the bracket and a piece of silver steel inserted into the file holder

Mounted the flywheel/crank in the bodged 4 jaw chuck turned the outside and bored a hole through the middle.

As I was putting a chamfer on the hole, I realised I had cocked up. I had misread the drawing and bored a 3/4 hole instead of a 5/8 one. After turning the air blue for a couple of minutes, I decided that the only downside was that it was now a bit close to the voids (is that the right term?) in the casting as you can see below. I think I can live with that.

The Crank pin was a simple turning job, but needed a square end on it, so i made up a quick ghetto filing guide for the toolpost and squared the end, indexing off the back gear.

And, here's the crank parts all finished, the slot still needs a bit of tidying up, but it all fits fine.

Obviously I couldn't resist putting it together.

And (after oiling it) trying it out on the lathe. It runs!!!

Thanks Paul, and yeah I think I'll keep the router for softer materials in the future

Well, I had a fairly productive weekend in the garage. I needed to face a block of mild steel to make the file holder. Not having a 4 jaw chuck for the Myford, I mounted my mini lathe 4 jaw on the faceplate.

The rest was all just simple turning, filing, drilling, more filing, a bit of threading and even more filing.

By the end of the weekend I had completed the file holder, slide, cheeks, tommy bar, con rod and wrist pin

Yep, I understand what you’re saying, and can see how the clover leaf could be a better solution.

However, in my scrap box I had the material to make up a top hat, and didn’t have the material for a clover leaf.

When I find myself with a scrap piece of plate large enough and some spare time I’ll give it a go.

yeah, to be fair, I was hoping for a bit better. At some diameters I’m getting a couple of tenths, and other diameters a bit more, with the worst being about 3 thou.

I’m blaming it on the scroll, which wasn’t in the best of conditions (and also maybe my file work when trying to repair it)

half a thou sounds fantastic. Have you got any recommendations if I decide to invest in a new chuck at some point?

Thanks all for your help.

this morning I stripped the chuck down and found that the jaws were very tight in a couple of places in the scroll.

A bit of work with a file sorted out burrs that had formed in those places. Then after reassembly, the chuck was a lot easier to tighten, but still had the same problem wit regards to gripping.

I made up a quick top hat and trued the jaws with a carbide boring bar and the top hat held in the back of the jaws (then reversed the top hat to the front and did the same for the very rear of them).

The jaws now grip fully along the length and don’t slip at all!

I was slightly worried about the work on the scroll affecting the runout, but after testing at multiple diameters I seem to be getting a maximum of about 3 thou.

thanks again for all your advice

ro

Ok, cool. Thanks for all the advice.

I’ll give the chuck a bit of TLC tomorrow and then check if it needs the jaws ground. Sounds like a fun Saturday project.

oh, and I’m glad to know I should be able to take even deeper cuts

J Hancock & John Maine: I’ve just tried giving it some welly, and I really had to fight it to get it to grip. I had to go so far that I was getting visible imprints of the jaws in the steel.

And to add info to Jason’s question, yes the imprints were from the rear of the jaws.

Jason: It spins and moves back. Just tried it and the mark is towards the back of the jaws. Can I just regrind them with a dremel held in the toolpost? Or is it not that simple?

Bill: I have lubed the scroll with the jaws taken out, but I haven’t stripped it down yet.

Edited By Ro on 10/07/2020 19:38:22

So, I’ve recently acquired an old Myford super 7 and I’m loving using it, with one exception.

It came with a 4 inch Pratt Burnerd 3 jaw chuck, and I’m finding that if I take a cut of 1mm or more on steel (EN1A-PB) the work will move in the jaws.

I have tightened up the jaws fairly tight, but after reading warning about over tightening I don’t want to really crank it down.

Having had a mini lathe for the last 15 years or so, I’ve got used to how much I need to tighten the chuck on that, and I’m definitely applying at least as much torque on the Myford, and probably a bit more.

So, should I just crank down on the chuck key to hold the work, or is there something I can do to the chuck to make it grip better?

Well, progress stalled for a bit on this project, as work got really busy and also I accidentally bought a Myford Super 7.

I put a bid in on one on the 'bay thinking I couldn't get it for that price and ended up winning :D

Here it is before I set it up and bolted it down.

It took a bit of getting used to, it's a very different animal to my mini-lathe, but I blooming love it.

Anyway, once I had sorted out tooling for the new lathe it was back to the filing machine. Next up is the swinging bracket that holds the table.

One side just needed facing off, so I clamped it to an angle plate on the faceplate and used an old carbide insert followed by a nice sharp HSS tool to finish it.

The other side had to have a ledge on it to fit into the slot on the standard, so I clamped it onto a smaller angle plate and marked the arcs for the ledge up. I centered it by lining the tailstock up to the center of the arcs and faced off each side up to the lines.

The last operation on this piece was to cut a slot for the bolt which holds it to the standard.

I couldn't think of a way of machining it on the lathe, so I ended up marking it out with dividers, chain drilling and filing it to size. This is where having a filing machine would be really handy

And finally, the 2 pieces fit together with a temporary bolt in place, next job is to make up the proper bolt and handle.

It's a nice sliding fit. Time for a celebratory beer