new cheap mdf machine

[Hobbiest]

Just couldn't get this idea out of my head, so I had to start on it today! Should be able to finish it this weekend, and this is the first machine that I will personally fire up and run! 3/4" mdf, aluminum channel for the ways, plastic cutting board for the slides, adjustable gibs, roughly 24" by 12" by 4" of travel. The nylon isn't great as far as linear motion goes, but I am surprised at how well it does work! Gantry moves very easily, with just a pinky of pressure (very technical term there!), and if held at 45 deg angle and nudged, sends into good sliding! Will use the FET3/HT kit from stepperworld. Total cost of mechanicals estimated at $45. I won't be able to work on it again until this weekend, but hopefully I will be able to finish it then. Sorry about the poor image quality. I can't understand why it pixelated when I made it smaller!

[mikeschn]

Hey Hobbiest,

That's looking good. And at that price, the electronics cost way more than the mechanicals. And we won't even discuss software costs!

Can you give us a close up shot of the slide configuration you are using?

Mike...

[Mr.Chips]

Good start Hobbist.
Interesting use of aluminum channel, serving as rails and to stiffen the MDF. Lengthwise rigidity is the weak point of MDF.

Keep those photos coming.
Hager

[Hobbiest]

The slide design is very simple. I think that I will change the pieace of mdf that holds the upper sliders to angle aluminum, with adjustment slots, as I just don't trust the wood here. It is too thin and weak. Also have to adjust the placement of the slides to give more surface contact area.

[Hobbiest]

I also will be stiffening up the bed by adding pieces of this aluminum t-slot, with 3/8" wood strips between to make a level plane. This t-slot is pretty cool...something like $12 for 36", and it uses 1/4" bolts in the slot. Eventually I am going to try to fab UHMW slides that go inside. Might try injection molding as well, but have to get D. Gingery's book first! My main goal with this machine, is to get a good working machine together, then offer plans on it. But the machine must be able to be built from hardware store parts, and be possible to get the parts in any country, not just the U.S. and Canada.

[gbennett]

Lee Valley Tools sells a u-shaped aluminum extrusion sized to accept the 3/8" x 3/4" UHMW strips that they also sell. They also have the aluminum t-slot extrusion.

Page 133 of the catalogue

or

www.leevalley.com

[Hobbiest]

Thanks gbennett, I'll check that out!

[DJ Morrow]

Non CNC content

The reason for your pixelated pic may be one of two things:

1. JPG is a lossy format. Each time you change and save a file, you loose some detail.

2. I use MS Frontpage to do a website for my motorcycle stuff and am always reducing the size of the pic's. When it shrinks, it gets "pixelated". In Frontpage there is a feature called "resample". When the picture is reduced in screen size, it doesn't need as much information to present the picture. The resample eliminates all the unneeded data. This also significantly reduces file size thereby significantly reducing download time. When you resample the image really clears up nicely.

Probably more than you wanted to know but...

[Mr.Chips]

Hobbiest,
Is your machine built out of Partical Board or MDF?

All the MDF that I'v seen is very fine grained, and doesn't have the color variations in your frame.

Hager

[DJ Morrow]

Here's the Lee Valley page with the U-channel and UHMW

http://www.leevalley.com/hardware/pa...urrency=1&SID=

Thanks, you've given me an idea for my own work in progress machine.

[balsaman]

I noticed that too. Looks like particle board.

Eric

[Hobbiest]

They said that it is mdf, but I wouldn't put it past them to not know the difference! I agree, it does seem more like particle board, but it is plenty strong. The particular 2 by 4 sheet used for this machine has been pulling duty as a workbench top for the last couple of months. I have a workbench, but it is always covered in junk! DJ...if you use that stuff from Lee Valley, let me know what ideas you come up with, I already have a few.