So I've decided to build a router...

[norby16]

Greetings,
Initially I posted a poll regarding which turn key router option is best. After about 2 months of shopping around I've come to the conclusion that I will build my own... Not working with nor having any experience with this before I'm sitting here with what I think is a right concept but considering my inexperience in this field I've got a big headache... Hopefully some of you can throw your opinions/recommendations at me.

The application:
I'm a plastics fabricator company planning to modernize my small shop to more precise standards and more capabilities. I'm building a 48" x 96" x 4" cnc router that will most often be cutting acrylic sheets no thicker than 1/2" of an inch and lexan polycarbonate materials as well. Lotta notches, drill holes etc will be made with this machine.

The newbie concerns:

The only problem I'm facing before ordering parts is not knowing the exact footprint needed to operate the table at atleast x48" x y96" x z4". Looking at aluminum extrusions I've compiled a large table that should be able to give me enough space to fill in the other pieces as I progress. Here is the top view of my aluminum table and its dimensions.


The X box represents 1 square foot of space designated for the z axis mounts/ etc. I think 1 square foot should be more than a safe amount of space. The center of the box marked X is ideally where the router bit will end up being/ or around that area. So the table will have motions capable of a little more than 48x96... 2" thick Aluminum extrusions will be used from top view for the moving arm as well.

I compiled a finance list to see if it would be worth my time building one. The answer is yes.

Entire aluminum table frame:
Legs- 2"x2" al extrude 6pc @ 36" = 135.78

96" length - 2"x2" al extrude 2 pc @ 116" = 127.40 ( I've created a 2 inch over hang on both ends to attach brackets ( not shown in the drawing ))

48" length 2"x2" al extrude 2 pc @ 60" = 65.80

Brackets to be used for table 2x2 22pcs = 104.94

Feet supports/ +- 20$

Electrical:

Completed turn key electrical package from motion tek quoted me $2375.
( supplier found on ebay/ 1200 oz motor package seems like a good deal to me... ) Please feel free to give me feed back on this as I know nothing about brands/ pricing etc. Just comparably I find it being a good deal.

So far total:
$2828.92
+shipping
+taxes
+the linear rails and racks n pinions to worry about.

New final total:
I'm predicting that around 5k will be spent.

Anyways I thought I'd bring this all to light in case there's some big fundamental flaw I'm committing that someone who has built or even worked with these before could point out I'd really appreciate it. So far useful links I've found:
www.automation4less.com - great prices on the aluminum
www.motiontek.ca - these guys cut me that $2375 electrical deal

Things I'm looking for and have no idea about:
Among other things now I need to find a good quality low cost rack n' pinion dealer along with a movable Z axis router mount with ball screws and some rails for all this. I like the rails found at www.motiontek.ca but would like to know what rails would you guys recommend best? With plastic shards everywhere it will be a very messy environment... Wouldn't want ball bearings chewing through that every time I use the machine...

Any feedback is welcome thanks!

[Kipper]

Looks a sensible approach to sizing a machine, If "I" was in the US I would definitely buy Gecko drivers, If you have a good nosy around on geckodrive.com you'll find a calculator which will allow you to know what size motors you need and then you can make a better decision regarding sizing and speed.

I'd go with V groove bearings and wipers to withstand the detritus from cutting plastic (VXB sell those in the US cheapish) Maybe something similar to the one I just finished making for a UK CNC'er would do for your Z axis....15mm rails 250mm long and blocks leaving 115mm travel?

[norby16]

Thanks for the post Kipper. I like the circular rails due to their rigidness. But if I use the V bearings and rails will gravity alone hold the movable gantry? I can create underside spring tension bearings on one side and have the pinion wheel underneath the other to create rigidness from top and bottom... Great idea only does VXB sell "L" rails for the V bearings or should I just use an L aluminum extrude...

Great picture of the Z setup, do you manufacture those? I will most likely mount a big porter cable router on there.

[High Seas]

Just a thought -- or 2.
1. You will be using this daily - I bet. So rigidity will help keep the system online and not down for tweaking. Aluminum extrusions -- which I like a lot - may move a bit through use and you'd hate to ruin a full sheet - I bet. Thats a downside of mechanical fasteners.
2. Can you weld? Know someone who can? Check out the Mechmate - its welded steel - and rack and pinion - and free pdf downoad plans. That will help confirm you sizing too - athough it looks pretty good.
3. Another option would be inshoreboats cnc ninegwt - as I recall is his handle -- similar to the Mechmate if you need more ideas.

Welcome aboard - and good luck!

Jim

[Kipper]

Thanks for the post Kipper. I like the circular rails due to their rigidness. But if I use the V bearings and rails will gravity alone hold the movable gantry? I can create underside spring tension bearings on one side and have the pinion wheel underneath the other to create rigidness from top and bottom... Great idea only does VXB sell "L" rails for the V bearings or should I just use an L aluminum extrude...

Great picture of the Z setup, do you manufacture those? I will most likely mount a big porter cable router on there.

I'm not sure if VXB sells the rails to suit Usually there would be 2 rails opposing each other with eccentric adjustment on the lower set.

High seas made a great post regarding the Mechmate router as it's a tried and tested machine (modified shopbot)

I don't manufacture the Z it was something I had a use for a few years back and finished post cnc...incorporates the radial support bearing into the motor mount.

[norby16]

Hey guys,
From looking at the various amateur rail setups I've realized that its basically a free for all. I'm going to take a closer look into all of them over the weekend to see which I see most fitting. I wanted to start ordering parts Monday but I think this might take me a bit longer to plan out. I kinda like the rail system torchmate is using/ has bearings vertically for stability and horizontally for rolling. I'm thinking maybe I'll make V bearings and rails for weight and precision while attaching side bearings for stability, just having a difficult time imagining it...

MechMate
I've ran across the mechmate website in the past. I like the look and I'm sure it works great but I want to be able to disassemble / assemble components where welded steel would be finalized. I find building my own design easier than following instructions... Maybe thats just me. And besides if I do this I'll be able to claim it as my own

Edit:
Just a thought, I started putting all my planned and measured table idea's and gantry prospects into Pro-E. Thanks to this I've already found one thing that I will do differently to increase X axis travel and next time I stop in at my shop I will measure the porter cable model I intend to use. Once I model the entire machine I will be able to see the EXACT travel distances with no second guessing before I order a single part... Last thing I'd want is have a router moving less than 48x96. Kinda funny that i just came up with the idea considering that I'm getting my degree in computer aided drafting... Of course if I sketch up something fancy I'll be sure to post.

[norby16]

Oh, anyone know and good rack n' pinion dealers?

[LazyMan]

www.stdsteel.com

Never ordered from them myself but many on the forum here have reccomended them. They are a fairly inexpensive source for racks but you will need to order you pinions else where from somewhere like mcmaster.

[norby16]

Welp, its Monday and I put an order request for a ready to go Z axis slide from k2cnc / router mount and a complete turn key cnc kit from motiontek. I swapped the 34 nema motor to the 23 nema so it will mount on k2cnc's z slide.

Meanwhile I got Mach3 on my computer, anyone know how to calibrate units of measure for the machine once the motors arrive using this software? Or do I need another software package? How do you "draw" tool paths and all that anyways? I do have Autocad / Pro-E and have never done any of this before. Am I missing something?

[norby16]

Hi all,
Hope you all had a nice Thanks Giving. Atleast those of you in the US. Anyways I'm stopping in for some opinions regarding X axis motion. I've already ordered some linear slides for my Y motion and now I'm deliberating if I should order the same type for the X travel. Originally I was thinking of going somewhat of a torch mate design were I mount some bearings on the aluminum and let it run up and down a piece of iron secured onto the aluminum table.

( heres a pic of what I'm talking about;
http://www.cncplasmacutter.com/images/brochure_shot.jpg )

The rails I ordered for my Y axis are pictured on the main page of this website here: http://automation4less.com/linhd.htm

They have not arrived yet, so I didn't have an opportunity to play around with them. Also I need to crunch some numbers because spending 100 bucks more or so and having this thing rolling accurately will be worth it. This will be for my business so I can't have garbage quality coming out of this machine.

Any pro's or cons on these Hiwin bearings and rails? Are other types better for the X axis travel?
As far as I'm concerned it will be more precise than my speculative home-brew linear design AND easy to install. Just screw on and go! I would purchase 2 rails and 2 blocks per rail for stability on each side of the table.

Any other linear motion suggestions instead of Hiwin for the X axis?

Opinions? Thanks!