I always love getting the pile of parts in the mail.
I always love getting the pile of parts in the mail.
What advice do you all have for cutting aluminum extrusions? I’m thinking of a metal cutting blade in a miter saw, partly because I already have a miter saw. My research online indicates others have done this with good success. Any particular metal cutting blades you would recommend? Or some other method of cutting you think would be better.
A miter saw designed for cutting wood isn’t great as the blade is turning too fast. If you look around, you may find a blade that is appropriate for aluminum and your miter saw although you may want to look at options.
Personally, I use a band saw for V-Slot rail. My unit is a few years old, but I think this is the current equivalent:
With a band saw you get fast precise cuts with minimal flash at the cuts and chips aren’t flying everywhere.
If I did more V-Slot rail, I’d probably buy a floor standing unit.
One solution, or at least partial mitigation for the blade speed issue that I saw online was to buy a smaller diameter blade. My miter saw has a 10 inch blade. I could put a 7 1/4 inch blade on it and still easily have enough cutting depth for my purposes. Using a coolant is an option too if needed to keep things cool. If I have to take things easy when cutting, that is quite fine. I won’t be doing a huge amount of cutting.
One concern I would have for a hand held bandsaw is square cuts. I assume you have a jig of some kind to make sure cuts are square?
I don’t know much about rotary cutters for metal - just high school shop class and the teacher said “don’t”. I would suggest that you read the article I linked about miter saws.
I’m surprised at how straight the cuts come out but I mitigate possible problems with the design and make sure that I can be a millimetre or two short without there being any concerns.
I did read the article. It was informative, but it didn’t say that cutting metal with a miter saw equipped with metal cutting(not abrasive) blade was a bad idea. The lesson appeared be more or less, make sure you have the right blade for the saw and job.
A smaller diameter metal cutting blade(in order to reduce tip speed) with a rated speed compatible with my miter saw’s rpm would be quite within the guidelines of above article from what I can see.
Allowing for some imprecision in the design is a good idea. I still want to start out with as precise a cut a is reasonably possible though.
The much discussed bed heaters arrived today! On Monday I plan on ordering the needed aluminum plate from a local fabrication shop. Exoslide order still enroute.
THIS IS NOT A SUGGESTION, I did this myself knowing the risks of my actions.
I happened to find a Black and Decker Chop saw at an outlet mall several years ago. I saw its RPM was only 5K. I bought it instantly knowing I could find an aluminum saw blade that would run within that RPM range.
Still use it to this day for only cutting aluminum. Have to remember to let the blade get up to speed and cut slowly. Your Blades MUST be rated to be able to handle a Faster RPM than your saw can produce. I cannot remember the name of the blade I am currently using but it’s from a local speciality tool supplier. Ran me about $300 just for the blade.
It’s good to know it works for you. Diablo makes a saw blade for non ferrous metals that runs around $90 for a 7 1/4 inch blade. There are others on the internet that say it has worked for them cutting aluminum, so that might be what I try.
I agree, I have used the Diablo blades, They are pretty good but have a short lifespan. I have had teeth come off the Diablo blades if you feed it too fast.
freud was the name of the blade I was trying to remember last week.
Its not a custom printer build without a bit of jank thrown into the mix
Hopefully the build doesn’t have to much jank!
Anyway, the exoslide order has now arrived! It appears to be a good quality product at first inspection. I quickly assembled a set and tested it on an aluminum extrusion after adjusting preload. I like what I see so far.
I’ve been meaning to call the local fabrication shop to order the aluminum plate for the bed, but keep forgetting at the right time.
On the bed note, what are your recommendations for bed thickness? Bolt spacings will be rows of 3 every 230mm. Is thicker or thinner(to a point) better? If thinner, it is easier for the bolts to flex the bed if needed, to counter any warping. On the other hand, a thicker plate should warp less than a thinner one. My Enders have 3mm aluminum for the beds. Would thicker, thinner, or the same be your recommendation?
@Jason, what size of Freud blade cost $300? I can find a 10" Freud non ferrous blade for around $120.
On Exoslides, I’ve been playing around with them and I’m discovering that there are errors in the .step file provided by the company. Unless you are using four around your 2020 rail, you’re probably going to have problems as what looks right on the CAD system will have errors in at least problems.
As for bed thickness, for the size you’re building shouldn’t it be 10mm or so?
As for support placement, I thought I said before that I’m locking in one corner (the origin) and designing the holes the supports go into the structure so that the supports can slide 1mm (0.25mm in the shrinkage direction and 0.75mm in the expansion direction) - with the size of your bed, you should be looking at expansion of at least 2mm and maybe 3 (find the coefficient of expansion for aluminum and decide on what you’re going to need). I first saw this done on my Voron and, while it’s done pretty crudely there, after a couple of thousand hours of printing, no tacoing.
I haven’t fiddled with any step files from exoslide. This printer will mostly be designed in my head, with the exception of the brackets and such that I will need to print. Good to know though.
As to bed thickness, I’m no expert on what thickness is optimal, but you are probably right, thicker is likely the better option.
When it comes to bed mounts, because the bed is so long, I’m putting the fixed point in the center. It reduces the max amount of travel a given bolt will have to have. And yes, a while back I did the research on the amount of expansion I could expect, and I think it was a bit over a millimeter total, if I remember correctly. Having some extra travel room is definitely a good plan.
I picked it up from Tegs here in Hamilton, Depot or anyone else did not carry it in the 12" version.
I can double-check the manufacture of it tonight when I get home.
The Saw I picked up was just a chop saw so it was nothing special, no Compound miter or any of that, made a saw cheaper so didn’t really worry too much about the cost of the blade.
THe Exoslide is exciting, I Wish I had more, Its like linear rail Lego…
If you are going to work with anything other than four together, it’s a LOT harder to work with than you would expect. As noted above, the .step files provided by Exoslide are not accurate and the company hasn’t responded to my emails asking for help.
After about two weeks of solid work trying to get a toolhead design with two Exoslides, I now have something that is square and should line up with a Micro Swiss NG (I’m also integrating a Super Pinda inductive sensor):
Honestly, I’d be very hard pressed to recommend them except in a situation where you are wrapping all four around a rail and not trying to create a custom application.
Well, I already have the exoslides, so I’ll tackle it and see how it goes. The hotend carriage itself will have 4 20mm exoslides. All the others will be 1 20mm, and 1 40mm exoslide. Time will tell if I can make it work.
From your attached picture, it does seem to me the way you are mounting the hotend is not working with the strengths of the exoslide system. I assume there is a reason it doesn’t work to put the vertical exoslide between the print head and the extrusion? Does it offset the hotend too much? The way the attached picture shows, you are putting the strain on the exoslide from an angle it probably isn’t really designed for. Maybe it doesn’t make as much of a difference as I think it does, but that is what it seems like to me. Or did you try it the other way already and found it didn’t work?