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Member postings for Lee Jones 6

Here is a list of all the postings Lee Jones 6 has made in our forums. Click on a thread name to jump to the thread.

Thread: Mill Tramming Complications - Debugging Help Required
09/12/2020 11:50:48

No reply from the website query I made, so I called up Warco.

Ended up speaking to Roger (the owner).

They're going to collect the mill and repair it for me. laugh

Thanks for all your help chaps, I really appreciate it - as always.

08/12/2020 11:46:22
Posted by Tony Pratt 1 on 08/12/2020 11:45:19:

Guess that's Bristol, I had to Google that one.

I did check that it was Googleable before posting. laugh

Yes, Brizzle is local slang for Bristol.

08/12/2020 11:42:20
Posted by Tony Pratt 1 on 08/12/2020 11:41:18:
Posted by Lee Jones 6 on 08/12/2020 10:53:05:
Posted by mgnbuk on 08/12/2020 10:41:56:

Right. And it's only now, after owning the machine for over a year, that I'm coming to know the machine well.

The clincher is that the warranty is only 12 months. sad

Lee, the 12 month 'warranty' period under British consumer rights act does no absolve the retailer from selling an item which is not 'fit for purpose' they are duty bound to fix it, can't remember where you are based?

Sunny Brizzle! smiley

08/12/2020 10:53:05
Posted by mgnbuk on 08/12/2020 10:41:56:

They could win the Nobel Prize for fiction with that.

Even if it was "within their spec" it wouldn't be great - 0.05 per 100 mm ? Even a budget industrial machine would be expected to be around 0.025 per 300mm.

It is unfortunate that the customer is expected to do the final inspection on new budget machinery to determine if it is within specification, as even budget machinery is not cheap these days. I think it is unreasonable to expect that a hobbyist without experience could know how and/or have suitable equipment to do such an inspection.

Right. And it's only now, after owning the machine for over a year, that I'm coming to know the machine well.

The clincher is that the warranty is only 12 months. sad

08/12/2020 08:59:22

0.035mm apparently! surprise

img_20201208_085730.jpg

08/12/2020 08:46:19
Posted by duncan webster on 08/12/2020 00:31:02:

I had the same problem on my Naerok. If it is similar at the base level (can't see in the photos on Warco website), if you make the shims with U shaped slots to go round the bolts you can get them in by slackening the bolts and pushing the top of the column sideways, no need to lift it off, and if you only back the bolts off by a turn or so no chance of it toppling.

Before I knew how serious this was, that was my basic plan.

To lower the head onto some wooden blocks situated on the table.

Loosen the bolts a little, then lift the column up just a small amount to shim.

However, this is now looking pretty bad, so I'll have to obtain some additional muscle and strip it!

08/12/2020 08:44:30

Conducted some more tests this morning as per the suggestions.

One side of the table is lower than the other, but only by 0.02mm over the whole length.

The head-raising test using a square was repeated, this time;

  • With the square clamped to the table
  • Test was conducted at the centre of the tables
  • Gibs were locked before each reading taken

Results were roughly the same (0.6mm over the height of the square [~200m,].

So I've emailed Warco to see if they can provide any insight.

I'll post a copy of their QA sheet when I can find a moment to locate it.

07/12/2020 21:04:33

The whole thing weighs nearly half a tonne.

I'd be surprised if the column weighs less than I do!

07/12/2020 18:34:55

It's not question of being bothered, or not. It's one of capability

07/12/2020 16:42:51
Posted by Pete. on 07/12/2020 15:55:04:

Surely the first thing to do, is dismantle it, take the column from the base and have a look, there could have been some machining chips on the base that got stuck between the two parts on assembly, or rough machining that could possibly just need a light stone over to correct.

Worst case, I'd go with scraping to correct if needed, it's a slow process that removes small amounts of material.

I'd have thought referencing the sole of the column to check for flatness would be a good idea, it might be a high spot that needs knocking off to bring it right.

I wouldn't go running a flycutter over your table personally.

I think the flycutter comment was for someone else.

Popping the column off and scraping would be no mean feat on a 400kg machine.

I would have to acquire lifting equipment from somewhere and learn how to scrape (it is on the list!).

The thought of doing so for the first time on my milling machine does leave me feeling a little nervous.

07/12/2020 13:02:56

The bed is much flatter than you will get with a fly cutter.

Also, that won't get rid of the lean. It will only help to avoid tramming the head, which is quite trivial really.

07/12/2020 12:05:33

The new set-up uses one of THESE and a 0.01mm DTI.

07/12/2020 12:01:54
Posted by Nigel McBurney 1 on 07/12/2020 11:59:19:

From the photo of the tramming set up holding the dial gauge, I would be very careful about quoting very small dimensions read by the gauge, the rods holding the gauge need to be much more substantial,to stop deflection affecting the readings.the rod in the mill spindle should be much shorter and larger in diameter to make the set up stiffer, the rod holding the dial gauge should be around 15 mm diameter min.My old boss have gone bananas at the set up.

I think you're looking at the old set-up, no? The one with the brass rod?

07/12/2020 11:46:36

And the hoist I used to install it has been returned to its owner.

07/12/2020 11:33:15

Yes, that Murphy is a swine!

I'll try to rectify it - probably by shimming, as I have no means to remove the column completely.

I considered machine epoxy, but that stuff is super expensive!

07/12/2020 10:39:13
Posted by Hopper on 07/12/2020 10:36:02:

Yes that definitely looks like a consistent "lean" on the vertical column, tested both ways with the square.

On the one hand its too bad its out of warranty but on the other youve used the machine for 18 months without this fault causing you problems. It does not wreak too much havoc if you machine each job with the head in the one position and use the quill for many operations. It is only when you say drill a hole with the head down low then move the head upwards to fit a tapping head and then the head is out of line with the hole. Or machining one part of a large casting with head in one position and then moving head up or down to machine another level of the casting and you find the head has moved half a millimetre along the x or y axis etc.

I was struggling to see why this would be an issue for me, as the head would still be trammed to the table.

But you are right. With every move of the head (to say, insert a larger twist drill) the head moves laterally.

Thanks for taking the time to write that.

07/12/2020 09:57:54

Interesting. I'll try to remember that for next time.

I came to the same numbers using trigonometry in just a couple of minutes too.

... and I ended up with a pretty diagram. laugh

07/12/2020 09:10:56
Posted by Hopper on 06/12/2020 23:31:12:
Posted by Lee Jones 6 on 06/12/2020 13:10:28:

How does this look, from a back of a fag packet perspective?

img_20201206_130659.jpg

 

It's out by 0.5mm over 180mm????

Holy leaning tower of Pizza, Batman. That's bad, even for Chinese junk. One heck of a shim you need there at over 0.75mm.

You might want to double check everything and make sure. Then try to determine if it's the column or the machine base thats been machined wrong and think about getting it remachined by someone who knows how to use a square.

If your machine is still under warranty now is the time to contact the seller. If they swap you for another machine, check it to as these things tend to be done in batches all the same and it's not unheard of for the replacement to suffer the same problems as the original.

Edited By Hopper on 06/12/2020 23:33:54

Unfortunately, I bought it in July last year.

Not sure what else to check.  These are the test videos:

[VIDEO] Z Test (indicator facing right)

[VIDEO] Z Test (indicator facing left)

Edited By Lee Jones 6 on 07/12/2020 09:19:24

07/12/2020 09:09:36
Posted by JasonB on 07/12/2020 08:31:57:
Posted by Lee Jones 6 on 06/12/2020 10:27:04:

Afterwards the head retrammed the head to within 0.015mm over a swing of 480mm.

Jason told me I could/should do better, so I had another go yesterday.

The good news is I managed to get to a point where there was no visible variance over ~300mm using a 0.01mm DTI.

Yes, do need to watch those decimal points, in the other post you said 0.1mm over 480mm not 0.015mm which I probably would not have worried about.

Your current 0.01mm over 300 is no different to 0.015mm over 480 give or take a micron.

The 0.1mm result was using the long janky brass set-up:

img_20200521_192422.jpg

After receiving the collet held indicator holder from Arc, I dialled it in a lot better.

This time I have it to probably <0.002mm.

Posted by Martin Connelly on 07/12/2020 08:45:31:

Don't mess about with converting to degrees and back again. Use ratios. 0.5mm over 150mm is the same as 1mm over 300mm. For your example the shim required would be 0.5 x 260/180 = 0.722mm

Also read up on soft foot. This occurs if the mating faces between base and column are not plane surfaces. Basically if loosening and tightening one bolt at a time causes the column to move you probably have a case of soft foot.

If you start moving the bolts holding the column to the base a torque wrench is often recommended to get repeatable results.Also tighten the bolts in the same order each time may be a good habit.

The machinists in the toolroom where I worked always used a fine flat stone on their machines and tooling to remove any dings or burrs before use. A light touch and figure of eight motion was all they did, they judged by feel if there was a problem with the surface so did not do more than one or two light passes. They were of course using very large rotary tables or dividing heads that were positioned by cranes and could easily ding the tables.

Martin C

Just remembered that if you tram in a pattern that matches the bolt holes then the shim value is as read on your dial indicator. So for 260mm given above measure over 260mm if possible or 130 to make a simple multiplication to work out the shim required.

I converted to degrees to obtain the shim stock thickness required. Not sure how to do that with ratios.

It's not currently possible to move the bolts at all with the tools I have. I've since ordered a large 12mm hex key.

I'm also waiting on the arrival of a Norton India Stone funnily enough!

I'll try the tramming trick too to double check my initial results.

Thanks all!

06/12/2020 13:10:28

How does this look, from a back of a fag packet perspective?

img_20201206_130659.jpg

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