I'm working on the final design bits of my first cnc mill and i've realized that I'm going to have to make some crude gantry plates by hand before i can have the mill 'self upgrade' I've heard about mdf for a lot of the early gantry plates but are there any other materials to consider? I was thinking about going to the dollar store and taking a look at their cutting boards. My plan was to get a piece of material some what close to the dimensions i needed and drill the holes as accurate as i could and trim it down to size using a dremel and other basic power tools.
Go for it. You might be hard pressed on the right thickness. There are plenty of builders that use temp plates to get started. Let us know how the dollar store works out. Joe
I would use phenolic plate rather than cutting board, that stuff is real flimsy, probably would be pretty hard to mill a good set of plates using them. Phenolic cuts and mills easily with regular hand tools and dremels, plus its rigid enough to cut a nice set of aluminum plates from if you like... CE grade is pretty cheap but you could always use XX, pretty affordable... Here's where I buy my materials at: Items in NorVa Plastics store on eBay!
What kind of thickness shoulld i be looking for in phenolic? I haven't done much work with it before. I may have found a few free pieces of mdf and flake board at 0.5"-0.75" thick. Some left over shelving material at my job.
you could use just the 1/4" if your going to make a set of more "permanent" plates in the near future or for a stiffer solution look at 3/8". I made the first set of plates for my F-117 CNC out of green G10, they worked great and I cut a set from 6061 aluminum later on with that same machine... You can try the MDF and flake board, just don't be surprised if they don't hold together.
G10 is tough. You could get long life out plates made from it if your happy with the holes. Wear a respirator while cutting this stuff!!
Looked up some numbers for phenolics and dang, with a flexural modulus like that on G10, you're right I could almost make them the permanent pieces. SAN DIEGO PLASTICS - Norplex-Micarta Property Comparison Those prices are very affordable as well. I'm starting to lean towards that phenolic. G10 is glass reinforced correct? That's gotta be great for the lungs.
Yes they could be permanent. They're very stiff and I oblivious to moisture. In fact, the set of OX plates I purchased a while back was from forum member SlyClockwerkz. He sells OX plates made of Garrolite (which has very good mechanical properties comparable to aluminum) for a really decent price (double digits). I don't know if he is still active, but shipping included it was a bang for the buck. Much better than going through the hassle of marking and drilling all of those holes with a respirator or forking up Laidlaw prices for something pretty.
With all this in mind ill order some g10 at 3/8 and see how it goes. On another note, what kind of tooling does one use for phenolics? If it weren't for the glass i would assume wood working grade would have been good enough.
I've cut quite a bit for it, carbide woodworking bit work fit and leave a good finish. There are "specialized" bits for composite materials but they're fairly expensive... Here is a link to the bits I use on phenolic, keep in mind you need a upcut if your drilling holes. 1/16" (.0625") CARBIDE 2 FLUTE ENDMILLS, DOWNCUT FOR SOFT PLASTIC (10) - 1/8" (.1250") CARBIDE 2 FLUTE ENDMILLS, SOFT PLASTIC DOWNCUT very affordable and fast shipping.... Phenolic tends to dull the bits pretty quickly.... Those are good for CNC use, anything carbide would probably work pretty well if drilling and cutting by hand..
Well finally got to the point where I was looking into specifics on ordering my parts. After shipping norva plastics is about $17 for a 6"x12" of 1/4" CE phenolic, which is some of the best prices i've been able to compare to. But I was able to find some 6061 on amazon with free shipping for $16, not prime eligible but still reasonable shipping times based on the expected delivery date. http://www.amazon.com/TEMCo-Aluminu...srs=12189304011&ie=UTF8&qid=1450415750&sr=1-1 For more or less the same price I figure I can work with the same material I intend on ending up on. Thanks for the material supply source though, might go to them for some material once this gets up and running.
Do you not have a metal retailer (or scrap yard) near you? I get my Aluminum (brand new cut to length) for three dollars a pound (current price). I don't mean to cause you buyer's remorse if you already purchased, but that piece at 1.81 pounds would have been...some math...er, um (Where is my calculator app??)...a little less than $6 from a local dealer.
I was under the impression that most scrap and stock locations sold much larger pieces. A 6"x 12" is the biggest I need and I also have no way of cutting larger pieces. The idea was to get a piece roughly the same dimensions of my desired gantry plate and drill holes into it to get something running until I could do a cleaner job with the machine.
Most places I have been will cut to size, but they charge $2-$3/cut. So if I wanted a 6" x 12" I could just have them cut 12 inches off a 6 inch wide piece. However some places may have a minimum amount they will cut off. In this case you may be better off with the Amazon purchase. I recently grabbed a 1/4" x 6" x 4 foot piece of aluminum that was laying in the cut-off pile. I figured I could get all my gantry plates (X and Y) out of it. When I got home I realized I needed 7" wide pieces. D-oh! I got that piece along with a 2 foot long 6" wide piece of 3/8 inch plate for a little over $30. I will definitely find a use for the 1/4" piece. As for cutting. I was going to use my table saw with an aluminum blade.
