New Machine Build- 8020 Router 72" x 37"

[debetto]

After weeks of looking around and researching, I've decided to proceed with my build. I am using 15 series 8020 extrusion and borrowing a lot from Glacial Wanderer's design. I have already bought most of the 8020 needed. Details are as follows:

1. 72" x 37" table dimension. I know this might be a bit too big especially since I am planning on 1/2" acme lead screws, making screw whip a concern...will most likely go with a 60" length and see how it goes. If whip is so bad, I can always cut further. Rack and pinion is out of the question for now.

2. After hearing all the good feedback, I've settled on CNCRouterparts for th bearing blocks, linear bearings, Z-Axis plate, and AB nuts. Ahren, I will be getting in touch to put in my order soon!

3. Kelling Bipolar Nema 23 Stepper Motors and drivers. CandCNC UBOB. Haven't made my final choice yet, but I am looking at holding torque in the high 300's to mid 400's range.

4. EMC or Mach 3 software. Again, haven't made final decision yet.

I will be usign the router primarily for making giant-scale RC Airplane kits, propellers, and MDF molds for composite lay-ups.

I will be posting pics and and a log of my progress as soon as I start building. Any feedback or comments are more than welcome!

debetto

[ahren]

Debetto,
It's always very exciting to see a new build start! As for the 6' axis, this can be made to work with 1/2" ACME. However, I strongly encourage you to use 5 start screws, This will reduce your required rotational speed by a factor of 5, which will do a lot to reduce whip. I'd also encourage you to order good screws from McMaster (usually they end up being Nook screws) rather than the crap screws from Enco, which sometimes aren't exactly straight.

Anyhoo, looking forward to your build (and your order . Good luck, and post some pictures soon if you get a chance!

Ahren
www.cncrouterparts.com

[debetto]

Ahren,

I will be getting the 5 start ACME screw from McMaster. I also plan to use thrust washers and clamps on both ends instead of just the motor side--if I'm not mistaken, this makes it a type C fixity and increases the critical speed.

I've been on the forums all night reading about motors and drives, and with all the choices out there, things have been a bit confusing. Do you think 382 oz-in steppers (bipolar parallel; with properly matched drivers and PS) would be enough for a machine of the size I am building?

I can't wait to get started. I will definitely be gathering all the stuff that I need and will be placing my order soon. And photos won't be too far behind!

Thanks!

Debetto

[jemmyell]

What do you plan to use for a spindle?

Can I suggest a Porter-Cable router with the PreciseBits addon collets and balanced nuts? These collets turn a PC router (not a laminate trommer) into a REAL CNC spindle with really low runout specs and easy tool changes.

Ahren, maybe you should research making a PC router mount for your product line? MAYBE with a dust hood also and a connector for a 2-1/2" vacuum hose?

-James Leonard

[lovebugjunkie]

Debetto

Yes, please post lots of pictures, I have finally realized I will not be able to purchase a bigger router so sometime early next year I plan on starting a build around the same size as yours.

One question, did you consider belt drive, my current desktop router has belts on the x and y and I have really became a fan of built drive. So I plan on going in that direction.

[Khalid]

lovebug

We are making 10' x 5' router driven by belt system..the router will start cutting till the next month end.. Using belts are very cheap and good option..

Regards

[debetto]

I do plan on using a PC router, and I have looked around PrecisionBits...will definitely consider.

I haven't really looked at belt drive. I am going with lead screws to take advantage of ahren's reasonably-priced bolt-on solutions. I'm a completely new at this and I want to make my first build as straightforward as possible.

[ahren]

In my former life, I was an engineer for a company that made belt-driven gantry robots (along with linear motor and ballscrew driven ones). The belts were extremely fast, but rigidity was not their strong suit, so I don't offer any parts for these. I'm not saying it can't work, but there are significant challenges in getting a stiff system with a belt drive. For larger machines, I am working on a bolt-on rack and pinion system for extrusion that compliments my parts, but it won't be ready until next year -- lots of testing and tweaking to do.

James, K2CNC sells a porter cable mount, and all of their mounts are compatible with my Z-axis plate -- you just bolt them on.with 4 10-32 screws.

Debetto, it's an interesting idea to use two bearing blocks to constrain the screw axially, and it could help for reducing whip. Looking forward to seeing it!

Ahren
www.cncrouterparts.com

[groomden]

Originally Posted by ahren For larger machines, I am working on a bolt-on rack and pinion system for extrusion that compliments my parts, but it won't be ready until next year -- lots of testing and tweaking to do.

Any chance of getting some teaser shots? When you say next year, do you mean anytime soon in 2009? I'm extremely interested in this idea, especially if the price is as competitive as your other products are!

[ahren]

Groomden,
Nothing that I can show yet, sorry. I'm still deciding between a direct drive and a belt reduction, and figuring out some of the parts. Hopefully early 2009 will have something for you.

Ahren
www.cncrouterparts.com

[debetto]

Here are the first pics of my new router build. Now that I think about it, I wish I designed it as freestanding. I think it is much too big for a table top. I have concerns about having enough rigidity, and I might have to beef up the construction.

It is in the very early stages, and I am very happy and excited so far. Next up are the following:

1. Cold-rolled steel plates, linear carriages, motor mounts, and the rest of the mechanicals. I will be using CNCRouterparts. I am planning on using 1/2"-10 5 start screws for all axes. I am concerned though that I may need to use 2 screws for the x-axis due to its width. What do you guys think?

2. 387 oz-in Keling bipolar parallel motors throughout driven by G251 Geckos, C11G breakout board from CNC4PC (I initially wanted the CandCNC UBOB, but I am not sure if it works well with EMC2 which I plan to use), and DIY power supplies.

3. As mentioned, EMC2 control software running in Ubuntu.

It is the holidays so budget is a bit of a concern. I will be buying parts in manageable chunks.

Thanks in advance for the feedback!

debetto

[CarveOne]

Looks like it will fit on a home built 4'x8' work table if you have room for that. You can add middle legs if you thing the x axis is going to sag a little in mid span from the gantry weight.

CarveOne