Mill Tramming Complications - Debugging Help Required

And scraping is not the appropriate method for removing the 0.75mm the base is out by. It's a finishing process, and an advanced skill level that takes a long time to learn correctly. Base would need to be machined to remove that much metal sensibly.

And you are right about not flycutting the top of the table. That would only take a cut parallel to the existing surface so no gain. It is the relationship between the dovetail ways on the vertical column and the horizontal ways on the machine base that the table slides on that is critical.

Of course, we are assuming that the top surface of the table has been machined parallel to the table's lower slideway surfaces at the factory. Perhaps a risky assumption on cheap Chinese hobby machines. I suppose you could check that by holding your dial gauge in the spindle as in your video but with the plunger reading off the surface of the table. Then run the table full length back and forth along the X axis. It should give 0 variation over the full length, or a few hundredths of a mm at most. Then do the same for the Y axis, maybe with a ground plate or parallel laid flat on the table to bridge the T slots. Any variation on the dial gauge indicates the top surface of the table is not parallel to the way surfaces on the bottom of the table.

The other assumption, as someone pointed out above already, is that the spindle axis is parallel in both planes to the quill axis and thus the quill movement. Hard to imagine it being half a millimetre out though. You could possibly check that by tramming the mill as you have done, which sets the spindle axis square to the top surface of the table. Then maybe use a square to eyeball that the extended quill is also square to the table top in both x and y planes. Or with your dial gauge mounted in the spindle, run it up and down the square as you did in the video, but by extending and withdrawing the spindle, not moving the whole head. You should get a 0-0 reading or within a few hundredths mm if the spindle and quill axes are in line.

Posted by Pete. on 08/12/2020 00:49:59:

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But it's an important lesson, when buying Chinese equipment, go for a mini mill, that way you can pick it up and throw the cr#p out with ease.

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I also not that a lot of these column tests are being done with the table at one extream of it's X movement judging by position of the feed stops. I'd check it in the middle and at far end and also make sure gibs are locked during column tests as even a Bridgeport will ag at full table movement.

Edited By JasonB on 08/12/2020 07:08:28

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.

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.

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.

They could win the Nobel Prize for fiction with that.

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.

The clincher is that the warranty is only 12 months.

Lee, under British consumer rights legislation the 12 month 'warranty'  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?

Tony

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