Well I am finally close to getting things put together. My build size is 5’ x 5’ x 8-9".
I am still waiting on electronics and bearings to come from china. But all my parts are printed and ready to go. My Z assembly has the camaro mod ready to go as well. I will test that and if I feel I need it I will and a 2nd set of X and Y axis rails. I already have the parts printed for the add ons.
The base of my build is 2 2 1/2’x5’ sheets of 1/2" phenolic. This stuff is a resin based building envelope material. It is rigid, strong and heavy. If I had to pay for it, it would have cost about $250. A spoil board will then be affixed to the phenolic.
I am thinking I will also print 4 sets of the axis support and place them at the mid points on all for sides for rigidity.
I should be picking up my Dewalt DW660 today or tomorrow. Only $40 Canadian. Barely used… its an amazing deal.
While I wait for my bearings to arrive so I can really assemble this beast, I decided I would play with how I was going to brace the outside axis rails. At 5’ long there is noticeable deflection with mild pressure applied with one finger. My original intention was to print the 3 pieces and cut conduit to make up the brace but I came up with this as I did not want to spend and other 10 hours printing more parts. I had already printed 4 of the top of the pillar pieces so figured out a way to use them.
I drilled out the hole on top of the printed piece slightly and drilled a hole in to the conduit to accept the 5/16 threaded rod I had left over from the Z Axis. 4 bolts and 7 nylon nuts later this is what I came up with. I has made that rail totally solid.
I thought about that but I do not have the room at the moment… Problems I see that are if you add the dual rod upgrade like Fernando Topete (4’x7’)did you machine will have to be like 6’x10’ to accommodate 4’x8’. Conduit does not have much strength at all and will sag under its own weight at 10’. I am interested in how much deflection his machine gets when both x and y are in the mid axis position with the dual rods. I have the parts printed and ready if I need to add the dual rods to maintain stiffness. I do not think I would be machining larger sized aluminium but for sure will be doing MDF, plywood and acrylic in 4x4.
Well for those wondering. I mounted it into the rails and I must say just moving it around by hand I can tell this version is much more rigid. I had the camaro rigidity mod added to mine and there was still fair amount of play forwards and backwards on each axis. This version still has a bit of play but noticeably less then V1 with the add on. I also extended the Z all the way down and tried pushing and pulling on it. This is probably the largest improvement on the is design… It was also noticeably stronger then V1. I cannot wait till I get this moving. Unfortunately my time available to work on this right now is almost non existent.
Finally some progress… This was my first plotting on my machine. Took 4 or 5 tries to dial in the stepper voltages… The X axis kept cutting out.
Just need to sand the rails a little more as the lines are kinda jagged in some places. But overall I am impressed with how it looks. Straight lines are straight and the circles look round.
Here is my basically completed build. I am running the 525 center and roller… New rollers are definitely worth the time. I am still waiting on parts to come in for my 2.8 watt laser, and I need to order some bits for my Dewalt but other then that she is ready to get dirty. Oh also need a spoilboard as well. That is 3/8" Phenolic I have used as a base… I Do not want my bits trying to cut into that stuff.
I have a little bit of binding happening on one axis about mid way. I have to figure that out then we are golden, I think if I just loosen off the 2 horizontal bolts on the rollers that might solve my binding. That or rotate the conduit 90 degrees maybe there is a slight bend.
I do need to figure out some kind of a platform of sorts to raise the work when using the router. I think there might be a little too much twist with Z being that long.
Yeah the legs on mine have about an inch showing, and I have 1.5" worth of spacers in there. I think I am going to cut down the legs this week. That will put the locks right on top of the feet. The shorter the legs the less flex the whole machine has, just make sure you have enough room for your material, I am usually using 3/4" or less. Not sure about that binding though, Never had that happen, I would check for a burr or a dent.
I am thinking of making some metal feet from flanges as well as adding some braces I had seen on someone else’s build. Problem really isnt with the perimeter structure but limited by the strength of the individual X/Y rails.
I originally intended on adding a hotend to this machine but probably will not anymore, so may cut my legs down to accommodate material of upto 6 inches in thickness.
But before I do anything major I am going to try routing some MDF and see how that goes.
Figured out my binding problem… The Horizontal bolts running thru the X rollers were too tight. I loosened them off and not it runs smoothly without binding, but not all the bearings are touching the conduit now. Should I be concerned? I tried tightening then till they just touch but it runs louder and motion is not a smooth. Does not appear to add any play to the axis though… Not sure how that is.
I do have one question… The belts on one of the rollers seems to wander when it moves. The belts are adjusted and run parallel to the rollers but yet it slides over to the sides on runs on either the retaining piece or on the roller mount.
Don’t worry about the bearing, it happens on that design for some reason.
The belt thing has to do with the motor mount flex, that is why I made the new ones. I wouldn’t worry about that either, it shouldn’t wear the belt too much. I just rebuilt the first machine I ever made, it was beat to hell and never failed.
Ok sounds good… I can probably slowly tighten it as the coating wears off the rails. I sanded them a bit but there is still quite a lot on them.
I tried redrawing the Jets logo I posted the other day… except I bumped the feedrate to 150%… the introduced a lot more shake to the lines. The worst was on the y axis. I think I had the feedrate set for 15mm/s as per the “basics” tutorial. That would make 150% about 21mm/s. Should this machine not be able to meet or exceed those speeds? I thought I saw people milling at 30mm/s. Although that just maybe from the still rough finish on the rails.
Is there a way to make a file that will run the machine in giant circles for several hours to break it in?
Drivers are set to 1 volt. Any lower and it cuts out after about 3 seconds. Steppers are 78 oz in.
I am pretty sure I wired them correctly… I joined pins 1234 with 4321 so the second stepper runs in the opposite direction.
I didnt run it very much before I switched to the new Rollers… but this never happened with the old rollers. Could I have done something wrong there? I printed 1 roller and 1 roller m for each axis.
Something is wrong. cutting out under 3 seconds is not normal, even if you under or over volted your steppers.
What drivers do you have, what stepping mode are you in, do you have active cooling on them, heatsinks? You really need to set them according to the data sheet of the driver and the stepper and usually 10-20% under for long term stability. What firmware are you using, are your steps correct, acceleration, pulley size, if your belts are too tight is can stall the steppers? Sounds like you might need to take a step back and check everything from top to bottom.
As an example even with a fan on the drv8825 drivers 1V is on the high end and you can get thermal shutdown if you have any cooling deficiencies, and that is greatly under volting the 72oz/in steppers. you might not be able to get enough power to your 84’s even worse if you are using the a49’s.
