Thanks Mary, I have to figure out how to get the the MDF home my "go to" doesn't have a pickup anymore! Hopefully soon I will have the extrusions and really get somewhere on this build.
Home Depot will cut it down to a manageable size. I believe Lowe's does too. It used to be HD would do one cut for free. Last time I was there, I had them cut my sheet of plywood into three 32 x 48 pieces. I didn't even have to turn the table saw on when I got home.
Yes i know all about the cut service , but they don't have 1/2" MDF in full sheets for some reason (they used to)!? there is a plywood and hardwood dealer nearby just have to make arrangements, I want to get a few sheets of 5x5 Baltic birch anyway. Meanwhile with all the time waiting i dismantled my old craftsman tablesaw, cleaned and Teflon spayed the trunnions, now it moves smooth! Took the old feet that didn't adjust anymore off and added 3/4" thick nylon block feet, cleaned and waxed the iron top... got to keep busy Oh the white mess in the saw is Teflon overspray unrelated and out of order... I bought a $20 aluminum cutting blade for cutting the extrusions, real happy with it, I tried it out the other day on some 1/8", cuts real smooth.. once i get the good Baltic ply I'm going to make a nice tablesaw sled to help make the 2080 cuts. Concord Blades ACB1000T100HP 10-Inch 100 Teeth TCT Non-Ferrous Metal Saw Blade - - Amazon.com
I didn't even think about the lack of half inch. Come to think of it, I haven't seen it out here on the West Coast either. I used particle board for mine because it was cheaper and I knew it would accept a sealer without swelling. I believe that is available in 1/2 inch if you want to substitute. Most importantly, did I mention it was cheaper. Great find on the blade. I may get one of those just to have around. I am now tempted to make a CNC plasma cutter. Don't really need one, but they look cool!
Sure could use particle board, might have to consider that for sealing the MDF torsion box i planed on thinned out oil polyurethane, or could probably use shellac (alcohol base). The Wood whisper guy on youtube used poly on his mdf torsion box
I would think that either sealer would work. I am a big fan of the water-based for cabinets and that is all I have used for more than a decade (maybe 2) and it is what I had on hand, which is pretty much the only reason I chose it. I have very little experience with MDF, so I wasn't sure how it would do with water-based. I had marine spar varnish (the real stuff, not Minwax) for protecting the epoxy on my cedar strip kayaks and canoe, but that stuff is way too expensive for my CNC project.
question about Double belts, anybody try gluing down the static belt (bottom belt)? This rubberized CA glue bonds to the belt and aluminum very well and should have less wiggle than any tape could hope for. the only issue i can see is that the glue would have practically no thickness, is the thickness of the tape needed? I know people are using the thinnest double sided tape they can find but it still adds some measurable thickness.
Unless the teeth of the upper and lower belts stay locked together to where the upper belt can't stretch along its length having two belts would seem to serve no purpose. My Ox is still a work in progress but I did a bit of testing a while back and 45 mil vhb was about the ideal thickness to keep the teeth in full contact beneath the wheels. The problem I was having was getting the belt to stick to the tape as rubber has low surface energy and really can't be gripped all that well by adhesives. A workable solution came from spreading Loctite glue on the rubber and letting it dry and then sticking the glue face to the vhb tape. But this was merely a workable solution, not a great one. I wonder if the CA glue you show would offer better adhesion.
Forgive my Newb ignorance but I am intrigued by this double belt concept. Can someone point me to some online reading about it? Currently I am watching my single belts stretch all over the place. Considering going to lead screws but my cut profile is 1500x1000 and it'll be expensive if I do.
Martin Barfoed is like the guru of doublebelts as far as i know with several youtube videos about it. Rick, Thanks, i was wondering about the need for the 45mil thickness. as for the need to do this, i'm not totally sure either, I had a 1000mm X-carve which uses gt2 belt (much thinner and weaker belt) and didn't have any problems with it. I think once you find the sweet spot for tension and depth of cut the gt3 should be fine on its own, but i wanted to try DBing it
If you already have belts and pulleys, then it would be cheaper to stick with them. If you are starting new, I found it to be cheaper to go with screws vs double belt for a larger build. I also wanted the precision gained. They come in 6 foot lengths from McMaster Carr. I made my own anti-backlash nuts using the cut-offs from the rod for a tap. If you purchase anti-backlash nuts then the price similar. That being said, if I ever build a plasma cutter or laser I will go with the double belts for speed.
I just re-watched Martins video above, he said the 1mm vhu tape is too thick (1mm is about 39mil) and the tape he now uses is "very thin"? Many people seem to be using this but the info is contradictory, might be due to tolerance being different from V-rail and wheels, some may need 1mm some may need zero additional thickness. Either way i have a winner for adhesion, I just tried pealing the rest of the glue sample i had off, takes a lot of force and it destroys the belt. you can see in the pic where i stopped after 2 hour cure and the next section where it was 24+ hours cure. Fyi i wiped the surface of the aluminum and the belt with acetone before gluing.
Is it cool that I keep updating the build as I go? Seems like many people upload the whole thing when finished, but this is going to take a while and I wanted to keep posting things in chunks. Not sure if the constant publishing is annoying? BTW, Baltic Birch Ply
Keep up the Publishing Gary. It is good to see how things progress, whether positive or negative, during a build. It gives an insight to the way you are dealing with problems as they arrive. Throwing out problems, for others to advise on and offer solutions. Offering hints and tips. You could say, this is what a Forum is all about. It can be daunting, and a little misleading, for beginners to read about a finished build which seemed to be perfect from start to finish, as they stumble, like the rest of us, from stage to stage of the build. You are doing a good job, and helping us all, one way or another. Well done. Gray
Thanks, Me too! very productive day today.. more details go into the "build" than I'll put here. Got the first and second coat of shellac on the top of the t-box, feels great, very smooth. Shellac wont protect as well as varnish which I wanted to do, but it's cold out (and snowing) and didn't want to stink up the house with the family home. Not a huge deal as there will be a couple hundred holes in this anyway once i get the machine built to make the vacuum feature work.
lol snowing here too!!! makes it tuff to take the boat out when the water is hard!!! good job so far!!
LOL, yeah lots of hard water around here too.. I have an issue with the build where I uploaded some pics and must not have hit the thumbnail button like i usually do, and now they are "attached files" at the bottom of my build that i can't move or delete. Cound one of you moderators help me out on that? thanks Gary
Finally ordered the V-rails and screws, next weekend I'll be doing things that look like an Ox! All I have left to order is the stepper drivers, PSU, and drag chain.. Oh been learning fusion 360.. wow my brain hurts
found a new use for Xtreme wheels, balance the HF dust impeller, added two 10mm button head M5 bolts and nuts to balance
Hey guys and gals, big day yesterday! got the v-rail in and got to building! build page updated. Question, what size cable chain should i order? I plan on doing full chain so i will need an x and y chain, I know the Y will need to be a bit bigger. is 10x15mm enough? The X-carve chain was perfect, but i can't find what size the chains were (i don't have it anymore).
I believe that it way to small. I used this on 15 X 30 mm both my x and y axis. 15mm x 30mm Black Plastic Semi Closed Drag Chain Cable Carrier 1M - Twist Chains - Amazon.com I was able to route everything through with a little room to spare. Very little. I was able to get away with two pieces for a CNC that is 850mm X 1500mm.
Been thinking a lot about what i was going to use for the vacuum table (to make the vacuum). I think my big Ridgid shop vac is on its last leg, and it's so loud! and the HF dust collector is not great at static pressure and it will be used for the dust pickup head on the OX router. Then i remembered we have our old canister vac for the house sitting on a shelf not being used... I figured i would be able to cut and cobble something rough but functional with some work. So i opened it up and found that the motor impeller one part assembly is perfect for this! these things create a huge amount of static pressure and are cheap as heck on ebay, i found a bunch for $25 so if i burn this one up a used replacement or even new for $50 is easy to find. Only thing i will need to do is build a small MDF box for it and put a PC fan in it with in and out cutouts to keep the motor cool. the box will help with the noise too, these things scream! the box will just mount right to the bottom of my torsion box table with the impeller opening over a 1.5" hole in the table to pull the vacuum for holding lightweight materials like balsa and foamboard. the fan housing is only 5.625" Dia motor and all 4.18" tall.
Spent the last two night getting the hall effect home switches to work.. and now they work, but I'm really questioning why I bothered. Typical i place material on the table somewhat randomly to even out machine wear depending on size, and disarm $X (unlock UGS) then move the bit to lower left corner of the material touch off in the Z and then "reset zero" then start the cut.. at no point does a home sequence really help me. Am i missing out on something? Could have used the last two days making the dust collection attachment sorry for the rant