[country kid]

Hey guys;

Im looking for a few ideas, planning on building a new machine for light production work which would be 5 hours a week. i have been contracting my work out but the turn around time is killing me (im talking about 5-6 weeks for some orders!).

So im looking at building a machine to take a 1200x2400 (4'X8') machine. Just wondering what people have done to make there own linear guides, or what you recommendation would be. I used V rails on my last machine and while they were great they are incredibly expensive in Australia, just wondering if there is an economical compromise. Between making my own rails v.s the accuracy and repeat-ability of the machine?

Peoples idea and what they have used in making their own rails/Drive system and the life span and accuracy they managed to achieve.

[WillyInAus]

Hey country one thing I will chime in and say is do you have the capabilities to get a full sheet on the table if that is what the aim is.
I built my machine for a half sheet for the above reasons.

You could try Vrails made from angle quite inexpensive you will just have to put some time into grinding them look to the Mecmate forum for more info I will say I have ever never tried it though or you could use rails like on the CNCrouter parts machines look to their website.

Machine that size would be to be running R&P from what I have seen.

[dharmic]

Going to be a bit of weight on a 1200 gantry which eliminates a lot of the cheaper/easier options.

I like the idea of angle if you're going to stick with ways of some kind instead of moving to (for example) Hywin linear rails with bearing carriages. Depends a lot on your priorities and in-house resources I guess - time, skill and effort making something or cash to get something up and running quick.

[babinda01]

Hi Guys
I have a custom extrusion that I use on the machines I build. It is a heavy section, with the ability to use either 20mm profile linear rails or you can put 20mm square mild or stainless steel in, and use it with Vee rollers.
I have been thinking of starting to market it for the DIY folks who ar looking for a heavy duty(industrial) solution. If you are interested I can post some pictures later this afternoon.

Regards
Andrew
Cairns, QLD

[country kid]

thanks for the input guys, not sure if Angle iron would have the life expectancy for running 5 hours a week (cutting time). it might be one of those situation where spending a bit more on linear carriages could be a worth while investment to prolong the lifespan and accuracy of the machine.

looking at a few similar threads the Hiwin carriages seem like a fairly economical option, and from my understanding, relatively accurate with a good life span, will undoubtedly increase the overall cost of the build but i would guess its a trade off.

as far as loading sheets, i bought one of those crown pallet stackers which is pretty good for moving heavier sheets around. i dont anything over 5mm very often.

id be interested to see if anyone has an alternative to hiwin rails, i think regardless for the longevity of the machine would be better suited to a hardened guide.

[rodw]

I think you are on the right track. I looked at using heavy duty dual door wheels which have a stainless steel wheel with a 5mm radius groove so it will run on the edge of 5mm angle iron but as I got into it, I figure with what you have to do you might as well do it right and go with the Hwin rails. There is some good pics on Willy's build thread from Muzza using the round rod instead of Hwin rails. I'm still struggling to sort out all of the electronics on my build thread but have made a bit of progress on the wiring on my build thread.

So let me know what size rail you choose....

[babinda01]

Hi Guys
Here's a couple of pics of what I use. As well, there are a couple of screenshots of the cad drawing of this extrusion.
As you can see it can be configured for either 20mm square bar with vee rollers running on it, or it can be used with 20mm profile rails fitted. It has slots for limit/home switch dogs and a few other bits and pieces. I use these with helical cut rack & pinions, or belt or ballscrews.
The section of the main beam is approx 50mm wide by 130mm high plus the bearings, the ali extrusion is approx 12 - 16mm thick in the main part of the extrusion. As you can see there is a void in the centre of the section, this is to either allow for the belt return path, or if extra stiffness is required a piece of 65x12 flat bar can be clamped in the middle.
Any question please don't hesitate to ask.

[skillalot]

For the rail axis, use profiled rails on the master side, and cam followers on the slave side rolling over straight steel bar. The rail will hold the gantry in place, the cam followers on the slave side only have to keep the gantry horizontal. The motors will do the rest.
For the traverse one big profiled rails should be enough, I wouldn't even use double rails there for just a plasma.

[country kid]

So i have some to a bit of a compromise; given i haven't build a machine for this volume of work, and looking at what i have manufactured in the last 12 months, there is nothing that couldn't be broken into a half a sheet. so with that in mind i think a machine with 1200x1400mm of useable area would be just as suitable, all be it requiring setup more often. The money saved in additional material can be put into a DTHC and higher quality linear rails. Looking at Ali-Express (was recomended to me by a friend who workin in the industry.... i never would of thought to use them) you can get 2X 1500mm lengths of HIWIN rail with 4 carriages for 280$.... realistically by the time iv mucked around working out a way to make my own system...... i would of spent this much money in my time value. so thats the way i evaluate it....

next issue will be DTHC........ as non of my previous machines have had it. It will make a good learning curve.

For your reference;
2pc 100% original HIWIN rail HGR15 L1500mm rail +4pcs HGW15CA flanged blocks -in Linear Guides from Industry & Business on Aliexpress.com | Alibaba Group

386$ landed.

another question, can you put a join in this rail? I.E butt to butt?

[dharmic]

Can cut it but I wouldn't try to join it. You may get it all perfectly aligned but I suspect you'll still get the railroad "clunk clunk" as the bogeys cross the join.

[country kid]

i suspected as such; only take one of the recirculating balls to drop into the "gap" and bump it. might give that a miss!