Lateral play in the spindle.

I’ve been doing more test cuts today, and my machine appears to have deteriorated rather alot since I last ran it around a week ago. There is alot of play in the center block, such that the cutter in the spindle can move around 5mm side to side or back and forth when only around 50mm below the gantry.

I was milling a simple pocket in some MDF and first noticed that the cuts ere neither straight edged, nor accurate dimensionally. This is about the quality of milling i’m getting at the moment.

Fusion360 to generate the Gcode, 3mm end mill, 1mm Depth of cut, 1000mm.min feed rate, 200mm/min plunge, 17000 RPM.

Tool path -

Cut -

Several bearings in the center assembly are failing to make contract with the tubes, i’m guessing various parts have delaminated and failed as well. Don’t know if there is anything i can do to rescue this mess. Clearing is not useable as a mill at the moment, but will it even be viable as a printer to replace the center section?

Take the center apart and see if anything broke, or if it’s just loose. Either way I would take it most of the way apart to really have a good look.

After slacking for a week or so, I got it stripped down and upon closer inspection it was the tubes that were too thin which was causing the problem. They were measuring in at 24.7mm and there was alot of play in the Z tubes, X and Y we’re not so bad and some play in those as well.

So, armed with my calipers I took a road trip to a metal shop and came back with some 25.2mm thick walled aluminium seamless tube for a grand total of £20 cut to length. now it fits really snug, all bearings in contact and much much stiffer.

For any UK guys interested I went to Forward Metals in B’ham, they also have an ebay shop, and the guy Tim will now know what your talking about if you want to talk MPCNC tubes with him.

Be careful with aluminium tube, I used it in mine (measured 25.4mm) and now it has all been squashed by the tight fit in the parts designed for 25mm conduit. Aluminium is just too soft. Will be replacing all mine with 25mm galvanised steel conduit