[MunchyMonster]

It has been awhile since my last post here, but you guys were great help while I was sourcing parts for my first all MDF woodworking CNC machine. I did indeed get the thing built and I've been using it to make other stuff. I must admit that there are upgrades I'd like to make. One of the upgrades I'm considering is to replace the MDF parts with Aluminum parts. A naive strategy here would be to simply by slabs of aluminum to replace the slabs of MDF. That doesn't seem like a good idea.

Given that I'm not made of money where am I going to be able to get the most bang for my buck if I want to start replacing the MDF parts with Aluminum equivalents? I figure she will look a little frankenstein-ish for awhile, but that's ok.

Also are there any opinions about using aluminum bar/sheet vs aluminum extrusions? Anyone else out there doing an Aluminum/MDF hybrid?

Thanks,
Munchy Monster

[riche543]

Hey munchy check my post called 2nd build it was back in 2012. I used my old Mdf machine to build a solid bigger aluminium one. It's still going strong now. Just use it for hobby stuff. I'm using tapatalk for chat here so couldn't paste link to my post , just check my posts.
Keep us updated .
Cheers
Riche .


Sent from my iPhone using Tapatalk 2

[BanduraMaker]

Can you post a few pictures of your machine? Without seeing what it looks like, it's hard to say where the weak points are…which is where you'd start your replacements.

[riche543]

There all here. http://www.cnczone.com/forums/hobby-...ml#post1057071


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[BanduraMaker]

I meant for the OP to post pictures of his machine. Yours looks all set.

[MunchyMonster]

Here's a shot of the z-axis router mount, just to make sure I'm posting pics successfully, Crappy cell phone pics sorry.

Attachment 228434

[MunchyMonster]

Alright that seems to have worked here are a few more.

Attachment 228436Attachment 228438Attachment 228440
From under the table
Attachment 228442Attachment 228444
Last two trying to get shots of the whole thing from above
Attachment 228446Attachment 228448

She's bigger than I thought she would be but she meets the design goal of being able to cut a "handy panel" (2'x4') straight off the shelf from the big box store.

Try not to make too much fun of her she's been working like a champ. I just can't leave well enough alone and figured an upgrade to ali might be a fun project to tackle. Especially if I an do it bit by bit.

-Mike

[ger21]

Other than maybe the spindle mounting area and maybe parts of the Z axis, I think you'd be better off building an all new machine from scratch, using this one to make your parts.

Building that same machine out of aluminum won't make it that much better imo.

[Trotline]

I agree with Ger21. I have a plywood machine, and planning upgrades has been an extreme hassle. I've come to the conclusion that I'll be much better off starting from scratch than trying a piecemeal upgrade. Getting a real performance increase calls for more than just upgrading some structural components. It really takes a new design, or at least, a radical re-imagination of the existing one.

Happily, there are a lot of components that can be re-used, such as steppers and drive electronics, and lots of other stuff. In fact, I don't necessarily even plan to change from plywood to aluminum. Plywood can be high performance. If that sounds silly, take a good, in-depth look at a De Havilland Mosquito, or Jerry Burks' "Big Bamboo" machine. http://www.cnczone.com/forums/cnc-wo...t-started.html

Luke

[ger21]

Plywood can be high performance. If that sounds silly, take a good, in-depth look at a De Havilland Mosquito, or Jerry Burks' "Big Bamboo" machine. Big Bamboo - New Machine Project Started

Or my new machine, if I ever get it finished. I'm building a mostly wood, 4x8, dual spindle machine with the goal of having higher performance than most homebuilt machines you'll find. You can build a very good machine from wood, but it can take quite a bit more time and effort. http://www.cnczone.com/forums/cnc-wo.../138890-z.html

Imo, the biggest limitations on your machine are the Z axis, and the aluminum angle rails. If you want a better machine, spend a lot of time searching Ebay for cheap used profile linear bearings. Build a new machine around those, and you'll be way ahead of what you have now.

[cyclestart]

Try not to make too much fun of her she's been working like a champ

There's some good ideas in that machine.
The router looks centered over the X bearings.
The Z axis is close to the Y axis.
There's i beam thinking in the design.
The wire management could use improvement

imo it's the joinery that makes or breaks these plywood/mdf machines. There's some evidence of a split in the gantry upright joint in pic #4 ??

Also are there any opinions about using aluminum bar/sheet vs aluminum extrusions?

Extrusions sure simplify things, especially for people without access to welding and machine tools.
Bang-for-the-buck steel tube and angle is near unbeatable, or at least that's true where I live and it's the route I'm taking.

My plywood/steel hybrid is currently disassembled for a redesign. Now I have no router Don't make the same mistake.

[wizard]

I have to agree with some of the other posts, use this machine to build a new one. That is if you have the space. If you don't have the space start from the bottom and work up. That is build a new frame to run the old parts on until you can upgrade them.

The problem is to get substantially better performance you need to rethink your design a bit, think boxy stiff sections. Further think real linear bearings.

It has been awhile since my last post here, but you guys were great help while I was sourcing parts for my first all MDF woodworking CNC machine. I did indeed get the thing built and I've been using it to make other stuff. I must admit that there are upgrades I'd like to make. One of the upgrades I'm considering is to replace the MDF parts with Aluminum parts. A naive strategy here would be to simply by slabs of aluminum to replace the slabs of MDF. That doesn't seem like a good idea.

There are many reasons why you should avoid doing that. But the overriding factor is stiffness and cost.

Given that I'm not made of money where am I going to be able to get the most bang for my buck if I want to start replacing the MDF parts with Aluminum equivalents? I figure she will look a little frankenstein-ish for awhile, but that's ok.

Ugly is fine as long as she gets the job done. However a one for one replacement of wood parts with aluminum won't do a heck of a lot for you. This especially the case if cash is an issue. Steel or aluminum tubing will do much more for you.

Also are there any opinions about using aluminum bar/sheet vs aluminum extrusions? Anyone else out there doing an Aluminum/MDF hybrid?

Extrusions, assuming they are of proper size are a far better choice that sheet metal. To go the sheet metal route would require a well equipped shop to form and weld. Beyond that to get the rigidity required the sheet stock needs to be rather thick. Even if you have the tools to build the required cross sections the cost is still very high relative to extrusions.

Now if cost is an issue, it certainly is with me, I'd think seriously about going the steel fabrication route. This especially the case if you go with drops and other cut offs. I've seen steel priced at well under a buck a pound this way. Of course you will most likely need some prime materials but the point here is that steel is often many times cheaper than Aluminum. Beyond that Aluminum Tee slotted extrusions will having you buying a lot of specialized hardware. This isn't to knock aluminum as it does have its place where weight is an issue. Rather I'm highlighting the rather huge price difference you will be exposed too.

Thanks,
Munchy Monster

No problem. Honestly if your machine is performing well for you I might reconsider the upgrade. If it isn't, getting significantly better performance will require a new engineering effort coupled with a willingness to spend more cash. This issue with cash is why I suggest a new frame to build upon, ideally next to your current machine. However if space doesn't permit that then you can incrementally build upon the new frame, shifting old components as required.