[Astor123]

If 2 1/2 inch pieces of mdf were in the original desing I figures trhat a 3/4 square steel bar between 1 1/2 inch piece and 1 3/4 inch piece would add just a little extra. Not gonna be used at real high speeds but i figured if I adding a little now it would be easier than trying after it was all glued up.

The 3/4" sq. bar might work (try it on both sides). The speed is not the issue here, you will see if mdf starts to bow when pressure is applied to the rollers, and if it does, you can always slap another angle to the outside. I would just use the angle iron cause it's easy and simple instead of making the grooves in the wood. Someone was asking if it's ok to mount it on its legs in a triangular position, yeah, but why go through all of that when it's easier to drill the holes on the flat part and perpendicular mounting will produce better support.

HDPE vs UHMW is one better than the other

HDPE is a little harder then UHMW and it costs less but plastic will be plastic. There is a type of plastic (I have forgot the name of it) that is used for insulating electrical components that has brown color like the core of Formica sheets with cloth fiber within the core and that stuff is better than any of the above. Just keep in mind that your cutting head will be way out there from the sliding Z mounts and the heavier the spindle the more movement will be produce when using plastic components.

[AJ Negvesky]

is anything used to attach the pipes to the skeleton on the y and x axis's like a gorilla glue or somthing.

[Sbthomas13]

I didn't use anything to hold the pipes to the support pieces for my machine. They get fitted into the end supports and the gantry sides and that holds them pretty well. I'm not sure what Joe does on his though.

[AJ Negvesky]

cut out the bar supports and the long runs for the table and started working on the endplates. When I got tired of running the router around the template I polished the (2) 36" bars for the y axis. HMMMM its about time to start figuring out how much HDPE I will need and order some of that. the bearings drill rod and aluminum angle should be in today. Gettin closer.

[NIL8r]

AJ, Great looking progress.

I'm not sure that his is exactly what Astor123 was talking about, but I've worked with "Phenolic" before. It's a reinforced resin product. (Really smells bad when cutting). Although, I've only used thin sheets or bars up to 2" in diameter. This stuff is extremely hard. There's many different types with various fiber types performing the reinforcement. You can Google search "phenolic". Another option is FRP (fiber reinforced plastic). But, I haven't used that before.

I think someone asked about gluing the pipes in another thread. I also remember that Joe pointed out rotating the pipes if they start showing signs of wear (flat spots). If glued, you wouldn't be able to do this.

[bkboggy]

AJ, good job on the progress. Looks very clean.

NIL8r, thanks for sharing the info, I was going to glue my pipes and now I'll think more about it.... rotation would be a good idea.

[AJ Negvesky]

Well got the end plates finished and the angle aluminum showed up so we cut and started drilling that. WOW!! the holes even line up somthing to be said for measure oh 200 times and cut once, then cut again. LOL!!

[AJ Negvesky]

now the million dollar question, I have seen posts several different ways.. I am about to order my Leadscrews 1/2 X 10 but with all the discussion over whip and stepper speeds, before I order the stuff I will put this question out there .

I have ordered the Probotix

3-Axis Monster Hybrid Stepper Motor Driver Kit

3x SideStep Bi-Polar Stepper Motor Driver
2x HT23-400-4 400ozin Stepper Motor (X- & Y-Axis)
1x HT23-260-4 260ozin Stepper Motor (Z-Axis)
PBX-2 Parallel Port Breakout Board
24Volt 4.3Amp Switching Power Supply
6ft. DB25 Male-to-Male Cable
3x 4" IDC Cable 10-pin


so would 1 start 2 start or 5 start be the best way to go the stepper drivers can be set at 1/8 1/4 1/2 or full step. I plan on doing more sign carving rather than cutting things out when done.

[elcam84]

I'm hacking (cutting) mine out by hand too. Jigs for the holes etc. I'm building mine out of scrap mdf and 1/4 ply for skins.

Actually started it a few years ago and... well back to it.

I'm using 1" pipe for the Y and 1 3/8 for the X as bits are available and the tubing is cheaper than gas pipe and much better stuff.

Will be using the scrap built 06 to cut it's nice cnc cut replacement and an 06 for a friend.


As for your leadscrew question. My preference is for the 1/2 10 5 start but it's really pricey compared to one start. $11 VS $60 a screw and then associated parts cost more too and no taps available to make your own stuff (make your own tap).

I'll be putting my hobby cnc 4aupc on my 06 and I use an astec powersupply looks like this http://tinyurl.com/9uhppo .
They use different plug in modules and can be daisy chained to up the voltage and manually adjusted etc. Very versatile once you learn how to mod them. Mine is a custom one so it's a little different.

[BobF]

AJ,
I use the 1/2-8 2 start on mine. Others have used both the ones you mention.
Your machine can runn a little faster wiith the higher start count.
I think the 5 start is current choice on the 4x4.

[Astor123]

Going with a Acme 1/2-10 1 start would be the cheapest way. You can set it up and try it before you go out and spend $ on precision screws. After all, the whole rig is made out of mdf that gives a lot so dumping more cash into it does not make too much sense. You will be surprised when you see what precision a 1/2-10 single start can do, unless you are carving really small stuff, like a quarter. If you are doing just signs, a 1/2-10 can be used to engrave a 1/8" letter. I would be more concern about the z axis and its stiffness than a screw.

[AJ Negvesky]

Found a local Plastics dealer that is getting me the HDPE pieces I need from cutoffs for about $20. The electronics are now mounted in their Protective case. and the glue up of the table has begun. As I put the bearing rails together I found that on the x axis bearings 2 nuts were ridiong the bearing on the outer edge of the bearing but 2 lockwashers and they now ride dead center of the bearing on the rail. I hope that is a good thing .

[bkboggy]

Good job on that progress!

[AJ Negvesky]

This stuff doesn't machine too bad and a good sharp chisel slices through it like butter. Thank god for that tabletop drill press that someone gave me a few years back boy there are alot of holes to drill. gonna try my HVLP paint sprayer to prime and paint this maybe that will be easier than a brush, or just make a bigger mess either way it will be fun..

[elcam84]

Looks good. That's the next part I need to make.

As for drill presses... I have a big floor one but when doing this small stuff I often wish I had a little benchtop model. Should grab the neighbors but...

I am going to prime mine with epoxy then use whatever paint I have. Got some paint left from painting the el camino and it dries quick.

If you haven't painted MDF before there are two tricks to sealing the edges. One is to wipe with a glue wash. The other my preferred is to lightly coat it with drywall mud let it dry then sand smooth. This will seal the edges allot and smooth it out. It's a common woodworker process when dealing with MDF. I don't like painting the stuff as it's a pain.

[troach]

sorry wrong thread

[AJ Negvesky]

Painting using Rustoleum primer by the quart and an HVLP paint sprayer seems to be working nicely.. Was gonna paint it white to match the HDPE but the gray looks real cool. No pics this time thru. and have to take a break from working on it for a week so till next weekend I will be watching everyone elses progress..

[bkboggy]

I used a spraygun as well. At first I tried the foam roller method, but after giving spraygun a try I wish I'd use it from the beginning. Covers more area and hard to get to places, plus it puts on thinner coats, which in turn makes it dry faster and more evenly.

[Astor123]

On your next project you guys might consider using a waterproof MDF called Medex. It's around $30 a sheet and it's worth it, no painting required and no worries about humitity. It looks exactly like a regular MDF and it's the same thickness, slightly less than 1/2". They do not sell this stuff at your regular lumber supply and the best way to find it is to call a sign shop and find out where they are getting it from since they use it a lot, or find a plywood distributor close to you.,

[joecnc2006]

On your next project you guys might consider using a waterproof MDF called Medex. It's around $30 a sheet and it's worth it, no painting required and no worries about humitity. It looks exactly like a regular MDF and it's the same thickness, slightly less than 1/2". They do not sell this stuff at your regular lumber supply and the best way to find it is to call a sign shop and find out where they are getting it from since they use it a lot, or find a plywood distributor close to you.,

Also known as Extera MDF