[IN-WondeR]

After having finished my previous machine, then I'm setting my sails for yet another, and probably my final build. I have now built a Mechmate, and a design of my own, and now that I have sold the last machine, then it's time to try to go all the way and almost go 100% professional in the build. So here goes again.
It will be a portal type gantry router something like Multicam machines, the machine will be driven by AC-Servos from DMM-tech in Canada, and Rack and pinion on x, and Ballscrew on Y and Z axis. I'm not sure if the machine will be using both a spindle and a drill, but for starters it will be running a 2.2kW China watercooled spindle.
Here's the first rendering of the main table, it will be very beefy and very heavy. Enjoy

[PaulRowntree]

What do you mean by a 'portal type gantry router' ? I like the mass of your design. How high is the table off the floor?

[Mad Welder]

Looks like a good design and as it 's your last you already have assimilated enough experience from previous designs/builds.

But I’m interested in your choice of Rack and Pinion selection..... for the gears to run smoothly you will have to allow for clearance between the gear teeth...... and as I’m only on my first CNC build how do you intend to compensate for this clearance/backlash eh?

[IN-WondeR]

Well, first of it's my bad calling it a portal style gantry router. It will be based upon some of the design elements in the Multicam 5000 and 7000 series. The steel table it self will weigh in at a massive 730kg without any extras on it. Then comes the gantry, linear rails motors electronics and everything else. The table top when machine feet and hopefully vacuum table is mounted would be around 75cm or around 2.5 feet.

I was planning on going with the Servos from DMM-tech, but I might change my mind and go for some large Nema34 Steppers instead, I know for a fact that 500ipm cutting speeds is possible with those, and that should be more than enough for most jobs.

As for the backlash on the rack and pinions, there will be none, the gearboxes I will make will be spring loaded so they will pull up against the rack with around 25pounds of force, which also should be more than enough to make sure they do not skip teeth. The rack and pinions will be module 1.5 17x17mm and the pinions will be something in the 24-30teeth range havent decided yet.

The gearings on the x motor will be hopefully 4:1 so I will have a Holding Torque of close to 6400oz-inx2 on the X axis, and that's ALOT... I'm thinking of going for a rack and pinion on the y axis also as I know this will work like a charm there also... More pictures and renderings will come in the weeks to follow. I'm planning on making this build within a few months so I can get my business up and running. Total build cost estimate for this is around $10.000,- all inclusive.

[Mad Welder]

Yeah of course the spring loaded helical gears should minimise if not eliminate backlash same principal as a leadscrew directly fitted to a motor via a backlash coupler.

Had a look at the Multicam 5000 and 7000 series on youtube, wow...... now that's a serious table your building...... will you post project build photos in this thread?

Good luck with the build:cheers:

[IN-WondeR]

Well, I'm not sure I will be using Helical rack and pinion even though they will run more quiet, but there's a lot more thrust load on the gearboxes when using helical gears than on straight cut rack and pinion.

I have never used leadscrews, only ballscrews so I have not experienced any backlash yet. I was thinking of going all ballscrew on the machine, but that would mean a big increase in build cost, and a sacrifice of speed. However precision would be way better than rack and pinion.

The 5000 series is a big machine, my table size will be 1300x2500mm so a bit smaller than the Multicam 5000 series. I need to keep size a bit on the low size so it will fit into the garage...

I will be posting all build pictures through the entire process. I just hope I remember to take lots and lots of pictures of this build. For now, heres a picture of my last build.

[Mad Welder]

....I have never used leadscrews, only ballscrews so I have not experienced any backlash yet.......

Apoligies when I said Leadscrew I did mean Lead Ballscrew but yup looking forward to the build photos. And your table size is also a monster of a project.

I have also quite a lot of build photos too but haven't posted them yet...

[IN-WondeR]

Yeahh, the table is quite big. I'm still pondering how to move it around when welded together. I also have to move it out side at some point when I have to get it painted. Otherwise I will have to paint it inside my skamll garage. And given the season of the year, then I might not have many options for painting but to do it inside the garage... I can make heat in there with my wood stove, so the curing of the paint will be accelerated.

[IN-WondeR]

Well I'm off to a good start. Damn this thing is gonna get very very heavy.

Here's a few pictures of some of the steel and the welding I have done so far. Enjoy.

[CarveOne]

Yeahh, the table is quite big. I'm still pondering how to move it around when welded together. I also have to move it out side at some point when I have to get it painted. Otherwise I will have to paint it inside my skamll garage. And given the season of the year, then I might not have many options for painting but to do it inside the garage... I can make heat in there with my wood stove, so the curing of the paint will be accelerated.

Get four moving dollies and place one under each corner. Place a piece of lumber on top of the dollies where the frame rests on them to help spread the load over the dollies. It will roll pretty good once you get the wheels lined up in the same direction of travel.

CarveOne

[IN-WondeR]

A little progress have been made... Now welded and the table have also been painted. I was quite high last noght from the fumes.

[CarveOne]

Looks really good. That's going to be a nice machine. I would like to do something like that for my 5' x 12' machine's replacement frame if I am able to do it in the next year or so.

CarveOne

[IN-WondeR]

I hope it will be very nice when finished.
The picture does not do the machine justice right now, it's more white than the picture shows. Right now, it's curring in the garage, with the heat from the woodstowe..

[IN-WondeR]

A few new pictures to add to the thread.
Got the topcoat painted to the base table, and also found a nice little tank for water for my HF spindle.
A 24Liter pressure tank with the membrane removed makes for a great little tank for the coolant for my spindle. Also got the ends of the cross bearers capped of with some plastic end caps. I think it look really good, and makes for less places where dust can settle. I'm also thinking of making bellows for my x axis, but it still only a thought for now.

Enjoy.

[ger21]

Excellent machine.

[Mechatronist]

This is an awesome build. What size tubing is the frame built of? And how do you make sure your linear rails are parallel?

[IN-WondeR]

The tubes are 200x300x8mm so they are quite heavy, big and rather expensive... Thankfully I got them at a good price due to some good connections..

Evrything have been levelled and checked and rechecked everytime I welded something up. The Rails are round rails, so hopefully there will be room for a little bit of leighway, but as far as I know the rails are parralell, if I wanted the tolerances even better then I should have gone for getting the tubes machined both on the top and the side to make sure of the 90 degree angle. But due to finances then I opted not to do this because it would simply be too expensive.

I also did cross measure everything so the tubes laid square on eachother, so that should not be a problem either. The tubes themselves are so heavy that nothing seems to have moved when I welded it up. at a massive 160kg pr. tube, then they are quite heavy.

[IN-WondeR]

A little update on the build.

I'm painting away, and oh boy what a mess, but hopefully it will look super great afterwards...

Enjoy

[Mad Welder]

Excellent build progress..... and this is turning out to be a very interesting build thread

One question pops to mind are the adjustable feet permanent?


:cheers:

[IN-WondeR]

Yes the adjustable feet will be permanent. They will however be turned down a bit so they won't raise the machine so high as tit is now...

And thank you.