mounting profile rail - Hiwin Manual vs. typical approach

[dsc]

Its for registration . A machined reference edge to butt up against makes getting your rails level far easier than without.

Ah but what if the edges which are use to butt up against are not parallel? It does indeed make assembly quicker, but the assumption is that whatever is used to mill the edges is near perfect.

I'd love to see you bend a hardened steel rail that's fixed every 80mm lol

Not planning to:) I was simply referring to m_c post regarding shock loads and possible movement of the rails if not fixed against an edge. Surely this will not be a problem when milling MDF:)

1. It all depends on what machine you use to mill the datum, so I'm fortunate enough to have a VMC at hand. (when i use this method i get a parallelism of 2um)

Lucky b*stard!;)

The reason for asking is purely to understand where the edge idea comes from, I do like the ease of assembly, when butting the rails against the premachined edges, but worried about parallelism.

Ad, how do you mount the carriages? similar approach against an edge with a side push plate via a block bolt?

Regards,
dsc.

[GTJim]

So if your a DIYer building a router out of box section what method should be used.

[AdCNC]

Yeh bud, if your milling a datum edge in for locating the rails then the machine your using to mill the datum with will have to be cock-on!

Regarding the blocks you always mount the rails like this and let the blocks find there own parallelism. So for instance when assembling a z axis mount one rail up agains the datum edge then mount the second, as for when you aline the second rail to the first; mount a bearing block on the first rail thats correctly mounted the attach a magnetic block and gauge to clock the second rail! This is a method of checking if you have milled both rails a datum edge or a way of aligning if you are using a single datum edge. then mount all the blocks and attach the second plate then attach a gauge to this and align this plate to either the first rail or the first plate (taking in consideration that the plates have good milled edges.)

[dsc]

That's what I thought Ad (ie. rail against datum and 'floating' carriages), but for whatever reason the manual suggests going the other way, floating rails and fixed carriage.

Regards,
dsc.

[dsc]

Just a quick question again on the linear rail installation. Hiwin manual shows this:



So master rail bolted, three linear blocks bolted to the axis plate and moving the thing up / down, bolting the second rail at the same time to make sure it's all parallel. This assumes that the two left-hand side linear blocks on the axis plate are in the same line ie. same distance from the edge and the third one is on a line parallel to those.

I have the master rail bolted down and it's pretty much parallel to the edge (within 0.005mm). I also have one block on the master side bolted and it's also cock on parallel to the axis plate (within 0.002mm). Is it a good idea to loosely mount the second linear block on the master side, slide [both blocks + axis plate] on the master rail and then bolt down the second linear block to make sure both blocks are on the same line / parallel? The whole process would go like this:



This means effectively using the master rail as a reference line, according to which two linear blocks are set in the same line.

Regards,
dsc.