My new 6040 improvement plan.

**magicniner** · 17-12-2017

Originally Posted by PaisleyPCdoctor

Okay, I'll look at profile rails.
In your opinion, what are the Chinese profile rails like? Their prices look fine, but most of the branded ones I've seen are just far far too much for me.

You can't do that!
You have previously clearly stated that here's nothing wrong with what you have!
:D

**Desertboy** · 17-12-2017

https://www.ebay.co.uk/itm/15-1500mm....c100011.m1850

This is what I used on my gantry I'm very happy with it

You could buy a set of 1500mm with 4 carriages and a set of 300mm with 4 carriages for £200 and then cut the 1500mm down to get the usable lengths of rail to fit X&Y and swap the carriages across.

**Zeeflyboy** · 17-12-2017

Originally Posted by PaisleyPCdoctor

Okay, I'll look at profile rails.
In your opinion, what are the Chinese profile rails like? Their prices look fine, but most of the branded ones I've seen are just far far too much for me.

Seems people have got on fine with Noulei from what I've seen... it'll still be an order of magnitude better than round rail either way. Some good sellers on Aliexpress (I've bought HIWIN there before and been very happy) that will supply to your specs.

Have at least a rough plan though before ordering anything, and do bare in mind that you are addressing one of many mechanical weaknesses in the design... so if the plan is to continue to mod this particular machine, worth having a plan of what comes next and whether that will affect your mods here. For example, to change to profile rail you will likely have to make a new Z-plate and spindle mount. Is it worth changing that over to profile rail as well to avoid having to change it twice? Now your supported rails on the Y-axis are a weak point, then the ridiculous floppy bed, then the thin bendy gantry arms, then the piss poor use of retaining bearings for the ballscrews etc etc.

You see what I mean I hope... Just think it all out (almost like a new machine design) before committing to buying anything.

Then once you've done that and other mods, now you have semi respectable rigidity and realise your extrusions aren't straight enough... at best out come the shims, at worst another redesign. Then you decide you could have done a better job just designing from scratch. It doesn't end :)

**PaisleyPCdoctor** · 17-12-2017

They certainly aren't expensive, thanks!

I'll look over the machine and see what the options for mounting are. A big fat back panel will certainly be needed.
Thanks again.

**Desertboy** · 17-12-2017

I have original Hiwin's on my Y axis and the clone rail on my X axis they feel identical to me.

That clone rail I linked to is in Germany so no import tax and only took 3 days for delivery for me although will be slower at the moment of course.

**Desertboy** · 17-12-2017

At some point it makes more sense just to use it as it for 6 months and then sell it as is and build your own from scratch using the lessons learned along the way.

I bet you'd have no problems selling it for what you paid for it as bad as it might seem it's still better than an xcarve or shapeoko so plenty of potential users out there.

**PaisleyPCdoctor** · 18-12-2017

I'm looking at the hiwin hgr15, hgr20 and hgr25. Not a massive price difference for 500mm length.

I'm leaning toward the 20 but only because 15 seems small and 25 is possibly overkill.
I would have 2x rails on x-axis. I have never touched one of these so I'm guessing.

Not gonna jump in and buy straight away, just need to decide so I can mock up with correct dimensions.

Any recommendations would be warmly welcomed. Thanks.

**Zeeflyboy** · 18-12-2017

HGR20 is the common choice - HG15 carriages can be very awkward to grease as there isn't a lot of space to get at the grease nipples.

HGR25 is overkill, but on my new machine I ended up using them on the Y-axis just because the dimensions suited my design.

**Desertboy** · 18-12-2017

If you're going to fit Hiwin style rails the correct choice is the one that's easiest to retrofit to your existing plates if possible at all.

15mm Hiwin are a PITA to fit with 1605 ballscrew and BK12 fittings you need spacers, I fit my ballscrew sideways on, on my Y axis to solve this problem but still ended up with spacers on the X & Z.

15mm was a no brainer for me, even with the extra hassles but I traded time for my original Hiwin's in the end cost me 12 hours on a Sunday and 6 hours in the week for my 1.2m Hiwin's and 45cm ones on my Z. Was it a good deal? Like my friend tells me my time is worth nothing lol.

**PaisleyPCdoctor** · 18-12-2017

So you went with 2x15mm hiwin on your x axis?

I was looking at my machine last night and weighing up the options. I think I can potentially leave my ballscrew and 20mm shafts on and ADD a 15mm hiwin, possibly 2 hiwin. Sounds crazy, but actually looks easier.

My main worry with the 15mm rails- spec says the attaching holes on the trucks are M3 threads. Is that right? Seems a lot of force for 4x M3 screws to handle.