Density – Steel (which the carriage is made of) is generally around the 7 – 8 g/cm³ – or Three times that of Aluminium! – win there, I can use a sheet of aluminium Three times thicker than the steel on the carriage and have the same weight (in theory)
Thermal Expansion – Translated this means that Aluminium expands by 24 micrometers per millikelvin. Also known as 0.000024 meters per degree
How does this affect the D9 Printbed?
When heated, the 325 x 325 x 2mm thick aluminium bed becomes a bit larger
Finally got a few hours over Christmas to knock up the X axis linear rails upgrade for the printer.
Printer seems to run nicely and i’ve printed a few small things….I’ll work on quantifying any improvements next as, right now it only ‘seems’ better, and print quality improvements are really marginal. The biggest difference was on the Y axis bed, and I suspect there are now easy further improvements to be had………
Ok, the rails are on and working a treat, kind of…
The right angled fittings I purchased to secure the 20×20 extrusion to the 40×40 have some little tabs on them, I can’t find any readily available way of securely making this connection with off the shelf parts so i’ll have to grind down one side’s tabs…
The slight amount of pressure this tab is putting on the extruision is enough to twist it and stop the MGN rails from running smoothly!
View from below…if I add a little drop down to the right hand carriage, it’ll be easy to re-use the existing limit switch by mounting it on the side of the 2020
Close ups of the existing limit switch and the protrusions on the right angled mounting block.
Overall, minor things , but shows you should plan things a little in advance and test fit stuff before ‘going for it’
Fortunately this is nothing a quick angle grind and carriage print can’t fix….which means re-assembling the original printer to print a new bit, D’oh!
The Cheapy ‘Hiwin’ clone rails and blocks arrived a while back and they haven’t really dissapointed. By that, I mean, I kinda got what I was expecting. Still, only a small premium paid and 3 workable carriages / rails……
Just running through a few ideas in Tinkercad whilst I await some parts to arrive….it pays to mockup things before committing to a design, I’m liking how easy Tinkercad is to do something that, on the surface looks quite complex………
on My D9, looking from the front, the Y axis rails are spaced at 202mm edge to edge….so it makes sense that an approximatley 202mm deep by 202mm wide square would form the most stable base available, whilst still using the original dimensions of the frame………..
The mockup above shows a base plate of 202mm square bolted straight to the Hiwin clone rails……also shows the 325mm outline of the heated bed – it’s transparent to help visualise
Unfortunatley, having a 202mm square base for the linear rails bearing blocks has prevented the 325mm moving bed from obtaining its full travel – you can see below the the vertical line of the extruder output is not too far from the centre of the bed, even though if the bed moves forward, the bearing blocks will run off the end of the rails
This image below shows how far the blocks need to move off the end of the rails to allow the extruder to almost reach the edge of the heated bed
The extruder can easily reach the end of the heated bed when the bed travels backwards – with the additional slight overhang provided by the 500mm long rails being used
I’m not going to be using a 200ish mm square base plate with my 4 linear rail blocks on!…
it’s looking like it’ll need to be a 200ish wide rectangle that’s hopefully not less than 100mm deep – as the linear rail blocks are 45mm!