1st Build, Second machine

[m_c]

It will be far easier to get linear bearings accurate.
Oilite bushes would have to be sized (either via boring, or reaming) after being installed to ensure accuracy, as oilite bushes are pretty soft things and will deform during installation, unless you use an accurately sized mandrel to press them in (even then chances are they'll deform slightly)

[m.marino]

Okay will do rework with those ideas in place and try to add the rest of the pieces in place as well so that it makes sense. I have to say that i really like working with ViaCAD 2D/3Dv8 (yes I am an unpaid broken record but it is soooo easy to get things right where you want them and surfacing is extremely easy. Will make the changes and see what other gems and insight you will be willing to teach me.

Michael

[m.marino]

Jonathan and CNCJAZZ,

Thanks you have given me a huge amount of insight into improvements for the gantry section on the rebuild and also on the new build (once the funds are in for that). I am having to replace the end bearings on the one I have and am looking at either getting replacements for now (to have the mill running and to get work done) or get the bearings that I am looking at getting for the rebuild. Think will go with a getting what will let me produce product and then buy the others as I build. Need to be able to make money to build better (more precise) machine.

Michael.

[m.marino]

Okay,

Now you really got me thinking of ways to not only improve what I have but make the new one even better. Also with the two carriage stacked like that on the Z I would assume that you need to increase the length of plate to allow the travel I want to attain. Which might not be a problem. Though would only one set of carriages on each side for the current rebuild be enough with only 150 -175mm of travel.

Hope to get some drawings done tonight and trying to figure out a space issue with the required space for the Z leadscrew and backlash nut/mounting bracket versus the height that the rails and carriage require to function. Looks like I will be needing to mill some stock down with not only datum slots but also with channel to allow space for the screw. I have access to 12mm Alli' for sure and might have access to thicker. Having said that would milling the 12mm down to a 6mm channel in the centre reduce strength below the desired levels? I am still learning metal and it tolerances and what it can and can not do. Which is different then what i do with metal for making reeds in many fashions as there you want the metal to bend.

Michael

[JAZZCNC]

Hi Micheal,

First depends what you intend to do with the machine regards the plate thickness. I've made various differant Z axis but only one that was made with thin plate. This had a long 220mm travel and was mainly intended to cut soft materials like foam,plastics etc. It was made with with cast off's and scrounged parts that the owner and me between us gatherd (Hence thin plate was used).
It's not ideal for cutting hard materials but the guy does cut every thing from foam to Ali with it. . . It's a belt driven machine as well, very quick and accurate.!! . . I love this little machine "The Cavemill" was so much fun to make and resonably cheap being made mainly from scrounged bits. Attached a few pics of the Z axis and some stuff it's cut.

I love making "Junk yard dog's" I'm just finishing off another I'll post a pic of.

Personaly I dont like to use anything below 19mm for a Z axis that is intended to cut hardwoods or Ali. If your using profiled rail and intend to cut datum points and slots for screw etc then you really do need the 19mm else your weakening the structure. Again depends on intended use but for hardwoods and Ali using Profiled rail then 19mm is minimum IMO.
Also I wouldn't recommend using 1 carraige per side no matter what thickness material, it's false economy because it will flex badly and you'll end up making it over again.! . . Esp at the travels your wanting.
Imo the Z axis is one if not "THE" most important parts on the machine, remember doesn't matter how strong you build the rest of the machine if the Z aixs flexs you'll have BAD results.!! . . . It's also one area everybody new under estimates.

Regards travel most of my Z axis tend to be between 120-150mm the one in the previous pics had 150mm if I remember correctly.??

Attached a few pics of Zaxis made all ways. All built depending on machine and material requirements. Hope these will help you design something to full fill your needs.

Cheers.

PS: The upstands on the junkyard pics are temps just for affect to give idea too intended owner and have since been made lot shorter.

Edit: Added Cavemill pics of stuff cut.

[m.marino]

Folks been buried in work.

Still chugging along but clients come first. Really need to get the rebuild on the first machine done though and if possible the second built as already have product that will need the length in it and have clients that want to buy. Why, oh, why do i get myself into these positions. Wish me luck and have the new drawings and hopefully more useful information up soon . Also mc_cnc I will try to drop you a line to see how to catch up with you.

have a good night folks need sleep.

Michael

[m_c]

I know all about those positions, but right now the brain is shutting down!
All I know is I woke up at 7am on saturday on the west coast of Canada, and I'm now sat at home having had about 2 hours sleep on the plane.

[m.marino]

Okay,

Here is tha much promised and hard to get around to drawing of v2. You will notice that it is not complete. I am still working away at it but would like some input. Will let you know any other problems might be having in the near future. Due to problems (flex of Y axis and Z axis dropping up to 1.5mm from a set position) this rebuild has to be done like yesterday and been working on it the last three days non-stop. This is what has made far enough to be label a version and put before you folks for opinion and evaluation.

Any and all opinions would be greatly appreciated as will be burningthe candle in to the long hours. Need this done to get product back up to stocking levels for a convention at the end of October. Yes thing s do go wrong at just the wrong time. Yes I know I need to increase the rail for Z to get 150mm.

Anyone wanting a DWG, STP, IGES file of this or the completed gantry router let me know.

Michael

[blackburn mark]

id think about putting both Y axis rails top and bottom or you are going to lose valuable space...

the way you have them now will have your spindle over hanging further than it needs to buy quite a long way

try to keep your spindle as far back as possible... every little bit will help, it may not alter the flex by much but im pretty sure that each little fraction of stiffness you save will reduce sympathetic resonance or vibration by a sh*t load

good luck

[JAZZCNC]

Due to problems (flex of Y axis and Z axis dropping up to 1.5mm from a set position)

The Zaxis dropping most likely won't be due to weak design problem but more probably an electrical problem, possibly a weak or under powered motor thou you'll still have the same problem if not changed.

Other than what marks pointed out then there's not much more to see or say.