Thread: A Simple Tramming Ring for the Mill.

Bobby likes the video.

Too late for lifting thingamajigs. The ring is boxed up, bagged and posted to 104 Ma......... I hope the surface grinders still at Ray's.

BT

Originally Posted by Stustoys

Hi BT,
So what was the pitch of yor cross slide screw?(I'm guessing from PC comment the cross slide isnt 0.125" pitch)


Do you have a 1/10th" or 0.001mm DTI?
I find Dial gauges are much less likely to show up this sort of movement unless VERY rigidly mounted.

But lets face it.... its not going to be much.

Stuart

I was just looking at Josh's video and noticed the Mercer was mounted on what looks like a Noga arm. The Compac I used is heavy and mounted on my Noga does not provide a sense of rigidity. The weight feels like it overrides the sprung fine adjuster. Anyone else with a Noga find this ?

I ended up mounting a tenth dial indicator on a Mercer base that features a 1" diameter post. A touch stiffer than the Noga.

BT

That did not take long

You have an keen eye bob, The Noga stand that I'm using is the big monster one the one with 1" dia posts and its very solid, I find I cant use a smaller noga stand without it getting too tetchy.

Incidentally I wanted to know the error in the flatness in the part, and the 10th and micron indicators where giving me little in way of readable error. so I set up the laser and did it that way, but due to the way i have it setup I can only get a reading for 55mm along its length The error is 0.000034" so about a 1/3rd of a tenth of a out over that 55mm.

Hmm. Perhaps you guys need an optical flat and a monochromatic light source...

Michael

Well the ring finally arrived here, a few days after I expected it too, I was starting to worry that it had gotten lost.

First job is to get it out to the workshop and let it settle on the surface plate for a few hours and then measure it up and see what it is like, and then decide on a grinding strategy.

I have been trying to think of a way to use the laser but it just too narrow for the optics to get a good purchase with making up a jig.

Michaels suggestion of an optical flat would be ideal, but I don't have any 10" optical flats or gauge blocks.

So I will be going old school and just mic'ing and indicating it.

Quick question Bob: is the internal and external cylindrical surface a measuring surface? if so should they be square to the flat face?

-Josh

Originally Posted by Brobdingnagian

If I align the non contact area the right way so that it has minimal force, and turn down the force way down on the chuck and block it out it should be ok.

I dont think you will have a distortion problem on a ring like that. But if you are worried about it, I have a trick,you could try to put some thing compliant under it when you do the first side. For that ring that's blue's up pretty well, a sheet of A4 paper will be enough. The contact points will nestle into it some what, causing equal pressure and less distortion.

A card cut from a manilla folder is common. On badly warped stuff like a new gib or retainer that's bowed during milling. I'll often put a sheet of 3mm neoprene rubber down. The magnet will still hold it, just dont stand down wind.

Once you get your first side cleaned up with out distortion, do the second side as normal to bring it back to parallel.

Regards Phil.

Ok, well I'm a little more interested in seeing what it is like than to leave it for a couple of hours.

I used a mar federal μmaxμm indicator to test parallel minimum -15μm and maximum -4μm.

I also took the chance to blue it up and see what it is like. The yellow is just there a contrast to hopefully see any smearing if my blue was too heavy.

here are the pics.

no contact all the way around, close but not quite to contact areas on the inside and opposite each other.

DSCN2616[1].jpgDSCN2617[1].jpg

I might just give it a quick scrape and bring that contact all the way round.

Half a cup of coffee later, we have a bearing not worth writing home about, but sufficiently even around to minimise distortion.

DSCN2618[1].jpg

Hello Josh,

I'm feeling awkward about this. It's akin to sending you pig xxxx and expecting you to turn it into stawberry jam.

The innner and outer surfaces will not be used for any measurement. I will probably paint them to prevent corrosion.

Thank you.

Bob.

Originally Posted by Anorak Bob

Hello Josh,

I'm feeling awkward about this. It's akin to sending you pig xxxx and expecting you to turn it into stawberry jam.

The innner and outer surfaces will not be used for any measurement. I will probably paint them to prevent corrosion.

Thank you.

Bob.

It's a non issue Bob, it took all of 15-20 minutes to get the bearing around, it took longer than that to take a photo and upload it. remember what marco says about 5 micron...
here it is all inked up ready for the first pass.
DSCN2619[1].jpg

First Skim pass: ink plus a little metal
DSCN2620[1].jpg
DSCN2621[1].jpg
DSCN2622[1].jpg
-Josh

Side 1: First (maybe final pass done).

Here is why you need to breakup your surface ground finish. if your plate is good, first it "hovers" then it "sticks"

-JoshDSCN2623[1].jpg

here is a good one inverted spotting

DSCN2624.jpgDSCN2625.jpgDSCN2626.jpgDSCN2627.jpgDSCN2628.jpgDSCN2629.jpg

Just indicated it.

Is better than half a tenth good enough :P I hope so because I'm bumping up to the limit on the surface plate.

-Josh

I'll shoot a video.

here is the video.

it is still uploading give it about an hour...

-Josh

Edited with working link

Originally Posted by Brobdingnagian

Just indicated it.

Is better than half a tenth good enough :P I hope so because I'm bumping up to the limit on the surface plate.

-Josh

I'll shoot a video.

Anything is better than the pipe flange I sent you.