[jimini]

You could try this.
it's an Eagle stting on a globe (interlocking parts)

[jimini]

Sorry that's just the globe,but it should get you started.
Let me know if you want the Eagle,I'll see if I can find it...Jim

[jimini]

I found the whole file, it fits on a panel about 16" x 21" x 1/8".

[joecnc2006]

I found the whole file, it fits on a panel about 16" x 21" x 1/8".

any pictures of it already cut and assembled?

[Rodm1954]

Thanks Jimini

I appreciate the code and will use it for a test this weekend.

[ljoe1969]

Jimini

Would you post the dxf for this file i get an error at line 19080?

thanks

[Vaughan Sage]

I'm in South OZ on 'STRALA DAY, good to see another ozzie who is interested in CNC!
I reckon your machine is looking great! Looks solid as rock BUT... I'm wondering what will happen with ally & steel mixed on large widths like this, different thermal expansion of steel & ally means your bearings will try to leave the sides? or I guess you'll have em preloaded a bit. Aside from all that I think you should have more bearings on the INside of the flat rails at the top, so that when you get offset loads from the spindle at max Y+ &Y- posi. that the whole gantry doesn't skew or rattle >> more rigid footings of your whole gantry. Instead of the gantry hugging the base from the OUT side you would get double close-tied grips from BOTH siderails. Try testing your rigidity that you have got so far... put a dial indicator on your gantry on one side (off centre)& just pull/push with a spring balance with a force of what your cutter might require say 10lbs.force, this show you what "specific rigidity" you have.... in any machine! You dont need the cutter to be running. I you can apply the force to the end of the cutter & clock the deflection in X Y or Z you get the summation of ALL the deflections in ALL the compenents, beams, screws, rails, bearings... this what goes boing every time a cutter tooth lets go of your workpiece. Deflections shown on the dial indicator will be different depending if the cutter is at full height, low down, left/right on the Y travel, etc. You should really apply spring-force the between the workpiece mounted on the suspended platform table and your cutter tip. Then you can add stuff to reduce deflections to immediate effect/improvements. Sounds complex BUT it's dead easy!

[Rodm1954]

Hi Vaughan

I had intended to put bearings on the inside of the rails but found it didn't need it. There are nine bearings on each rail (total 18 on X axis) and the gantry has a cross brace above and below the bearing assembly. The gantry is very rigid with no play on the bearings and no flexing. At this stage I am going to run the machine and see what happens. I can always add them later or swap out the bearing assemblies for linear bearings later. If it performs well I will swap out the acme thread for ballscrews.

The aluminum was used to reduce the weight of the gantry. Steel was used on the base to keep costs down and also to add weight to the machine. The bearings are slightly preloaded but not enough to cause drag.
I have no idea about the different thermal expansions of the materials. This is a hobby and I have no engineering background so it is likely that I have created a problem by my choice of materials.

Thanks for the feedback.

[Splint]

Well done Rod,
very neat machine you've built there. I wouldn't be worried about thermal expansion differential between the steel and alloy componants as the overall dimensional change will be negligable.

Cheers
Splint

[Rodm1954]

Thanks Splint
Thanks for the heads up on that as I was a bit worried about it and there is not much I can do about it now. I have just run the machine in jog mode in TurboCNC. I have a full day tomorrow visiting (got to keep the boss happy) and I know what I will be thinking about all day.
Roll on Sunday.

[whirlybomber]

Rodm, did you draw your machine in CAD?

If so, would you consider putting the plans up on the site for others to download (ala Jgro?)

[Rodm1954]

Hi Whirlybomber

Sorry this machine evolved as much as it was designed. I don't know how to use CAD software yet and are trying to fast track the learning process.

I should have done full drawings before I started becuase it is much easier to fix with an eraser than remake parts.

Making these machines is addictive and I am thinking as much about making the next one as I am about using this one. Those first steps (pun intended) are a big high.

[Rodm1954]

Well I am pumped. The machine turned out better than I expected and with the trusty pencil attached as a makeshift router I am getting good results.
Speed is 900mm (about 35 inches) per minute which is not bad for first setup and having such a heavy gantry. I am running Mach3 and I am very impressed with it.

I hope to improve the speed as I learn a bit more and develop the machine.
Photo of finished machine and a sample of work. I have added knurled wheels to the motors, wiring, limit and home switches. I need to make a switch box with E stop and a mount for the monitor and ............

[Mike F]

Rod,

That is one neat, clean machine you have there and you should be proud of your efforts. I just don't know how you guys find the time to complete projects so quickly - I'm envious!

Mike

[Rodm1954]

Thanks Mike,
I appreciate the feedback. I am beginning to think these machines are never finished as I keep thinking of things to do to it.

[Rodm1954]

Mounted the router last night and did a test run tonight.

Did a quick and dirty graphic in Corel Draw and then imported it to Mach3. Didn’t worry too much about correct spacing and I have the depth of cut a bit low for these characters so excuse the result. It cut both sides of each letter and cleaned up the curves. It is cut into a piece of white faced masonite (compressed fibre board). I can recommend Mach3 to anyone starting off in this hobby.

I hope you get a laugh at the wording.

[Weldtutor]

Rod
That is a great machine you have put together.

The explanations & photos here in your build log are excellent! Thanks for sharing your experiences.

Congratulations on the first cut. You do seem to like turnbuckles.

What format did you use for the Corel Draw file into Mach3 ?
WT

[Rodm1954]

Weldtutor,

Thanks for your comments.

I saved Corel drawing as DXF Autocad release 9 with curves. I read this on the forum a while ago and it worked fine for me. Just altered feed and depth of cut in edit gcode in Mach3 but I think this can be done during the import process. I have a lot to learn yet.

[jimini]

Sorry I just now noticed your request.
I hope this file will help you.

[jimini]

Whoops you asked for the dxf files, try these, again, sorry for the delay.Jim