Micro Router Pro crabbing / X belt slipping

[MLeadbeatter]

Our school has a Denford Micro Router Pro it has developed a problem when you jog the carriage it (in the x axis) sounds like the belt is slipping for the first 20-40- mm then it runs OK.
It looses its coordinates half way through some jobs it started to cut in a different plane.
At one stage the carriage would not go past half its length in the x axis.
Could this be a firmware problem or a stepper motor ??
I have upgraded the firmware using easy upgrader

[Steve]

Hi,

It sounds to me like a mechanical issue with the axis crabbing.

I will check the forum to see if I can find instructions on how to cure this, if I cannot find I will write some.

[Martin]

You need to clean the inside of the nuts on the X axis. These are the triangular devices with 3 screws on the front left & back left of the X axis assembly. If you remove all 6 screws you will be able to wind them back & maybee able to remove any dust inside with a small brush & vacum cleaner. If not you can remove the 2 bloccks on the left hand side of the lead screws & remove the nuts to fully clean. It is important that both nuts line up when placed back in. the easiest way is to fit the back one then wind the front on & check if they are correct. It is is important that both leadscrews are fully in line.
Also vacu out the holes behind the nuts & make sure you are spraying the machine with silicone spray which needs leaving overnight to fully dry.

[Steve]

Had a look and cant find any instructions on this.

What martin says is correct but I will add a bit.


Move the machine to the middle of the X travel.

Before loosening the nuts mark the body of the nut at the top with tipex so that you can reposition them in the same orientation.

Now remove the screws that mount the nuts to the Pillars. You should then be able to push the beam away from the nuts.

The nuts will be visible as in the photo below. Clear out all the dust from the nuts and pillars with an airline.

Check that the slide moves freely on the rails without the nuts connected especially at the home end of traverse where you have had the problems.


Reassembly is important because doing it incorrectly could cause the problems you describe. I will describe after the photos.

[Steve]

The photos above are from a Router 2600 but the principle is the same.

If you have previously dissassembled the axis and did not mark the nut orientation then you may have to take extra care checking the next bit.

Position the nuts on the screw with the tippex mark at the top. Push the slide back towards the nuts slowley untill the carriage reaches one of them.

The pillars should be flush with both nuts (indicating the beam is square to the X axis). If both nuts are touching the face of the beam then you can put the screws in loosly but do not tighten.

If one nut is flush to the pillar and the other has a gap tightening would pull the beam out of square and cause crabbing. This could be caused by someone pulling out the nuts to clean them and not marking them clearly, then reassembling out of position This would cause the beam to crab and the slide to stall. If there is a gap them pull the beam away from the nuts and wind one of the nuts 120 degrees then push the carriage back up. repeat untill the carriage is flush with both nuts then you can put the screws in loosly but do not tighten.

Now drive the X axis back towards the home position with both the nuts loose. This allows the nut to float on the ballscrew and find its own centre. When the carriage gets to the home position the nut is close to the supported end of the ballscrew and will be alligned. At this point you should tighten up the 6 bolts that secure the 2 Ballnuts.

Spray the screw with dry silicone and leave for a few minutes to dry then try jogging the machine.

Hope this makes sense?

[Steve]

Another couple of Photos.

One shows the beam at the end of travel which is where it should be when you secure the nut with the 3 screws.

The other looking across the machine shows both nuts secure.

If the nuts are fitted correctly if you loosen the 3 mounting screws on both the flange of the nut should stay flush to the towers. If one of the nuts springs away then it could be incorrectly fitted.