5c collet chuck alignment

Good call, Steve

Glad it worked out O.K. for you.

MichaelG.

For your viewing tonight over the coco I took a quick video of my 5C earlier this evening. As I said it's a customer return that had passed through a couple of peoples hands but I understand it may have originally had green and yellow packaging. It either cost me a myford backplate or about 1 sq ft of 5mm steel, can't remember which, either way it seemed like a good swap to me.

TIR of taper inside the chuck looks to be 0.0005" ( 0.013mm) and against the shank of a 1/2" Dormer cutter about 0.0006 to7" (0.015mm). Seems to be good enough to get a nice slow running steam engine that is happy to tick over on a couple of psi to an IC engine that will do 10,000rpm. If you want to make a rocket to take you to teh moon then maybe you will want more accuracy but thsi does for me.

Edited By JasonB on 23/01/2016 07:26:42

Nicely corrected, Jason

As a matter of interest; how bad was it before you worked on it ?

[that is, after all, what the supplier was selling]

MichaelG.

I would just like to say a massive thanks to everyone that has contributed one way or another. I have taken every single bit of advise on board and i am delighted to say perseverance has paid off!!

Checked the nose this afternoon in-between work on my Axminster DTI and it was still jumpy, about 0.01 out which is ok i guess but i wasn't convinced with my clock... So i paid a visit to Midland Metrology The reason i have put a link to this place is i was astonished by there friendliness, help and advise and the time they took with helping me. I asked them about a lever DTI preferably a secondhand branded one, they guy said that they didn't really have any lever type DTI's in secondhand at the moment then paused and took my to a draw full of clocks and said these all need looking at or have parts missing, see if anything is any good to you, I ended up finding a Mitutoyo 0.01 DTI that was only missing the lever... a quick look around and i found a brand new lever and spanner to assemble it! The best part is he said i could have it for a tenner! I then asked about pin gauges to check the collets, when i explained what i was doing and the trouble i was having he dug out a box of imperial pin gauges and said there are a few missing but what size are you after i had a quick look and said the 1/4 would do just fine (i know i was using 1/2" originally) but that was one of the gauges missing, he then took the 1/4" gauge and took it to there test room and check that it was running perfectly true and perfectly round. After he confirmed it he gave it to be and said there you go just bring it me back when your done! I was over whelmed by the level of service and trust they have so i thought i would let you all know if you are after any secondhand or new measuring equipment these guys are well worth a visit or phone call.

Any way back to the chuck... So new DTI set up and re checked the nose and hey presto no movement! I was over the moon, next was to check the 1/4" collet with my gauge pin and amazingly even that was dead on! My needle didn't appear to move at all, bang on 0 no matter how slow or fast i spun the chuck and it was repeatable! Short of getting a 0.005mm clock i am happy to say thats as true as it gets

I think the morel of that story is keep persevering and make sure you buy quality equipment, although its old or secondhand doesn't mean its not as good, infant far from it, my £10 DTI proved to solve the majority of my headaches. If i had the money i would buy a better quality chuck but it turns out that some of this Chinese stuff isn't that bad after all, just gota choose carefully i guess. I would also say the cheaper stuff requires a lot more time and patients than a more expensive brand. These are just my findings any way.

Thank you all for your help and advise

Steve

Steve

I'm glad you have no got a system that is working properly but your last posting has got me wondering what was the real cause of the error.

I dont understand how or why the Axminster DTI should indicate errors that do not show up on another device. In principle for testing concentricity the DTI does not need to be calibrated or even high quality, it just has to be repeatable and have a indication range relevant to the purpose.

On your original tests with the Axminster gauge, when rotating the spindle did the needle oscillate over the same markings consistently each revolution?

Ian P

Hi Ian,

In answer to your question i forgot to add that i had to do some slight tapping with a copper and hyde knockometer, When i clocked it with the Axminster DTI in the nose is was about 0.02 out, taking into account the 0.03 i was getting on the silver steel i figured it was part down to alignment and part down to the silver steel. As you saw on the photo with the two clocks inline you can see it was +0.03 on one and -0.03 i decided to put the Axminster DTI in the nose and tap until i got it down to 0.01 the problem i then had was as if the DTI had to settle back down? Almost as if the tapping had caused it to un settle, in addition the bezel is very tight so when i tried to turn it to zero i would move the indicator slightly and its would screw the reading. I kept going until i had it sort of repeating but then for no reason it would shift/ jump about 0.01? It would go between 0-0.01 then jump to 0.03-0.04 then barley move then go back to 0 which made me doubt the clock as it just wasn't repeatable at any point. I even marked the chuck so i had a basic reference to go off. I then tried to put a plunger in at an angle and that barley moved but it wasn't ideal however it did give me a better indication that things were running as they should be. It was only when i put my new indicator in there could i then prove it was true. The problem i had was the in accuracy of that Axminster one, it was almost as if it was picking up something on the surface even though the surface was smooth.

I think i would mainly put to down to the indicator and silver steel. Initially it got me close enough but for that last bit of certainty i needed something that hopefully would give a more accurate reading.

Hope that made sense

Steve

.

I would have thought that destination planet Zanussi would have been more fitting to your age group and desire.

Nick

Can't quite remember but could probably knock a zero off so maybe 0.005" and not true to the axis of the lathe either which is why I skimmed the back as well as doing the inside edge of the recess.

Good result Steve, look forward to seeing that rocket

.

Steve,

Just going back to Jason's observation about yout 1/2" collet, and ^^^

It might be worth checking the keyway dimensions in your RDG collets.

... useful dimensioned sketch on this page.

My reason for mentioning it is that I bought BCA adapter from RDG on which the keyway was just a little short [they use a Horizontal Mill to cut them] and the key 'digs-in' before the taper seats properly. It is currently of ornamental use only; but I will get around to extending the keyway someday.

Glad to see that it's all going well ... and thanks for the link to Midland Metrology

MichaelG.

Edited By Michael Gilligan on 23/01/2016 08:09:21

So that's how the ornamental turners get all those eccentric patterns in their work

Seriously I wonder it it may be the pin that is at fault as the 1/4" collet is out even further? But with that amount of protrusion I would not have expected it to engage the tapers. Maybe they have started making them with an undersize taper to allow people to regrind them

Edited By JasonB on 23/01/2016 08:22:49

So that's how the ornamental turners get all those eccentric patterns in their work

.

Hi there, Steve,

Just a suggestion: Take your plunger-type dial gauge in to your friendly metrology emporium and ask them if they can supply you with an 'elephant's foot' tip for the plunger. (The ball-end tip should unscrew to allow other tips to be fitted. ) The flat or 'elephant's foot' type has the advantage when 'clocking' round stock, especially small diameters, that you don't need to present the probe so precisely to the job.

The reason I suggest taking the gauge with you is that there are two standard screw threads, metric vs unc. so it's good to be able to 'try before you buy' !

Being able to visit the emporium gives you the great advantage that the cost of the extra tip won't be swamped by P&P costs and the transaction won't be burdened by the minimum order charge imposed by some tool suppliers.

Best regards from my armchair,

Swarf, Mostly!

Edited By Swarf, Mostly! on 23/01/2016 11:18:22

Jason i think you have hit the nail on the head. I checked the collet as you suggested Michael and and everything is with in the dimensions posted. I then tried the 1/2" collet in the chuck and tightened without any stock. I then placed the silver steel in and tightened and this is the result

Also thanks for the advise "Swarf, Mostly!" when i go over to drop the pin gauge off i will take my clock with me and see if they have a set of tips, I think i remember seeing them whilst i was there?

I have had a few new 5C collets that required the key way to be extended. At less than £5 a time I can live with that as it is only a few moments on the mill to correct them.