OK, so like many others, I've been lurking for a long time, and have had some help from you guys which has been great! So now I've finally got some time on my hands to start my router. My shop has been in need of a cnc for some time now as my business produces some difficult parts to make by hand. I also plan to start making some precision templates for my dealers.
Purchased all the steel locally plus rumaged through their scrap bin for odds and ends.
Ordered the following...all on it's way:
-55" supported hardened rails w/pillow blocks from vxb.com (x axis)
-425oz Xylotex 4 axis kit (2 for x axis)
-3 49" racks (part# 200012) from stdsteel.com
-8mm ID ball bearings (y and z axis)
Hoping to cut:
-Mostly MDF, some polycarbonate, acrylic, light aluminum cutting
Racks on the side of the table to drive the steel gantry. The Z-Axis will be MDF for now because I have no way of *inexpensively* machining the metal to make mounts... etc, just basic metalworking tools. Still need to buy a PC router, a cable organizer, and misc. nuts and bolts and extras.
This machine has grown from the original design of a 12x12 all MDF/acme router into what it is. I've drawn up (with my limited autocad skills) two different designs which this has changed from, so I'm just kinda wingin' it.
2 questions before ordering any more parts
1. Where do I get gears for my racks?
2. Should I gear down the motors or use a direct drive?
OK - Pictures!
The metal from our local fabrication shop.
All welded together. My poor 944's new home is outside the shop...
The start of the sides of the gantry.
I'm interested in a steel router of this size, will be following up on this thread.
More pictures coming soon...
About the gearing issue.. How much should it be geared down? 1:2, 1:3 ? What would the benefit be?
I'm getting ready to order the gears and am not sure what to get.
By the way -
Greolt - your blue router is a big inspiration of mine. Absolutely an awesome design - and your input is always appreciated!
I use Geckos but there are quite a few blokes over here using the Xylotex driver and they say that the practical speed you can rely upon is about 300 rpm motor speed.
My thinking when deciding on gearing ratio was as follows.
Belts and pulleys are not cheap and because of the compact design of my mounts it was not desirable to change this part once made.
In contrast the pinions are quite cheap and easily changed if ratio did not work as well as hoped.
The theory is that it is best not to go below 20 tooth with my size rack. Upper limit does not matter.
So I started with 24 tooth pinions and 4 to 1 reduction ratio on the pulleys.
This has worked very well for me so no pinion size change was needed. This is approx 100 steps per mm (1/10 micro step)
I'm using similar motors to what you have ordered and with Mach running at 25000hz I can rapid at 7500 mm per min all day with very brisk acceleration setting.
That's about 375 rpm. Remember I'm using Geckos not Xylotex.
If I bump it up to 60000hz it will rapid at over 15000 mm per min but this is way too fast for my comfort.
Remember that my machine is smaller than yours so it is not as far to go before reaching a limit.
Might also be worth getting an idea from Xylotex what a reasonable top RPM can be expected with that combination.
Hope this helps, Greg
up to 14 hours of labor...
Those rails are well worth the money, I can move this ~40lb gantry with little more than a light breeze.
Any comments, suggestions?
kEEP IT UP .. I AM CONTINEOUSLY WATCHING UR PROGRESS.... I WANA SEE THIS MACHINE RUNNING MAKING FLOWERS AND UR DREAMS IN REALITY..:_)
Hi, I am studying different designs and component costs. Could you tell us about how much the rack and pinions costs ?
Looking Good. I just sold my cnc a few weeks back to a great fellow member of the zone. Now I am looking to build another one. I am gonna follow this build. It looks like what I had building up in my head. Gonna be a great looking router. I am gonna mount my rails on the sides about 6" below the table surface. There is another router a member here has built and It looks great. Hope he dont mind if I post one of his pics. But here is kinda what I had in mind.
I'm up to 20 hours of labor so far. Kinda had an oops moment, didn't take into account the rail and bearings for the lower gantry support and ended up with very little room underneith, so it's gone. Thats what I get for building without much of a design. It is very sturdy with just the top support, and now has rails on it. This thing is so smooth, it could probably be driven on just one side with no problems.
It will better to use Ball screw in place of acme rods:-)