My first design

[archerks]

Finished the design and ordered a lot of the parts, should start work next week. If it works when done, it will be used commercially to help make the custom archery bow grips. Check them out at www.torqueless.com

Blue - Extruded Aluminum - $350
Red - 1" Aluminum Plate - $88
Grey - Misc Aluminum - $50
Brown - Acme/Ball Screw - $150 to $350
Green/Yellow - 3/4" hardened rod and pillow blocks - $320
Nema 34's, Gecko's, BO card, Power Supply $900
Mach 3 software - $250
Misc. - $300

Does anyone have detailed instructions on installing the ballscrew - hardware needed.

If all goes right I will add a 4th axis indexer/rotary.

[Khalid]

Mach3 $250??? ...i think it is near $$150

[ger21]

Don't use unsupported 3/4" shafts. You're going to spend all that money and end up with something that flexes too much. Not sure how big the machine is, but two of these are less money than you have listed, and would work much better if you can cut them to work for both your X and Y axis.

http://www.vxb.com/page/bearings/PRO...ystems/Kit7429

[fatal-exception]

I agree with Ger, don't use unsupported shafting. It's not designed for milling applications and will flex so much that you will see reduced tool life, out of spec parts, and headaches galore. Use at least OPN bearings on fully supported rails, or better yet, the square, multi contact type such as HSR or better. If you are cutting anything more than styrofoam, you will need it...

Paul

Edit: Plus you spending a reasonable amount for the other components, do the right thing and buy the proper components for the linear movement. You will be happy that you did.

[archerks]

Thanks for all the come backs, I really appreciate the info.
My typo - Mach3 $150 not $250
Size of CNC bed - should handle a piece 24 x 36 inchs.

I was wondering about the shafts...
Changing to supported shafts will increase the cost about $300,
Going to linear rail and slides would increase the cost about $620. This is using new rails by ABBA (25mm). 2 rails at 48 inch and 2 rails at 34 inch with a 8 blocks total comes to about $950 plus shipping. They are the cheapest I could find anywhere. If anyone knows of a good set at a decent price, please let me know.

[ger21]

Originally Posted by archerks Going to linear rail and slides would increase the cost about $620. This is using new rails by ABBA (25mm).

Unless you're gantry will weigh over 1000 lbs, you don't need 25mm rails. 15mm's will be fine. Although the price probably won't be a whole lot less.

Better to spend more money now, than to spend twice as much later when you need to rebuild and re buy. If your patient, Ebay can save you some money.

[CNCfun&games]

Hi,
Welcome to the scavenger hunt................

VXB looks fairly reasonable but you can also get some good buy's on eBay!!
Also Check: use-enco.com
They have threaded stock, Acetal rod (DELRIN), all types of steel rod stock from 3/8 to
1 -1/2 Dia.
If you don't want to machine your lead screws try: http://search.ebay.com/_W0QQsassZpremachine2004
they have 1/2-10 Acme screws 48"lg w/Delrin nut for $35. (machined both ends)
Remember: you don't have to pay list price for this stuff anymore!!!
Happy Hunting!..............W. Smith

[cncspear]

Hi archerks,

Honestly, I am concerned by the looks of your machine that it will not be stiff enough to produce quality cuts in dymondwood at any decent speed or depth of cut. Seriously, if its for hobby fine, but if you are going to expect a return from it in your business I would build it as stout as you possibly can and use quality components. Its going to be great fun building it but you also want your investment of time and money worthwhile. Last thing you want is a machine that will dance... you know... "rack, twist, shimmy, and shake". This will force you to slow it down. Then you won't want to use it cause you are still faster making your grips by hand. Then it turns into a $2500 dust collector.. Sorry for all the sarcasm man, but you get what I trying to say.

I don't think everyone realizes how difficult it is to work Dymondwood. It is seriously hard stuff. Resin impregnated birch, that is hot pressed to about half its original thickness. I've personally worked with it on my router and its like twice as hard as any hardwood I've ever worked with.

Here's one of my dymondwood pieces:


I would take a long hard look at where you can stiffen up the machine. Your rails have been already pointed out above. I would suggest you put an actual aluminum table top on it instead of just spanning the frame with a wooden spoil board. These guys here sell cast aluminum tooling plate cut to size for a fair price (imo):
http://www.discountsteel.com/index.c.../itemID/77.htm

Also, build your Z big enough to accept a full size router, not just for a dremel or roto. You can certainly give it a try but in my opinion I don't think those little routers will do the job when it comes to dymondwood. Remember, if you can't get the material out of the way you are going to be snapping bits like crazy.

Just my 2 pennies.

Gil