You sound like you need an emotional support animal, Jim. I'll send you Vincent.
You sound like you need an emotional support animal, Jim. I'll send you Vincent.
Math is tough. Let's go shopping!
I have a Shapeoko 3 XXL and a Tormach 440 if you need anything made for the beast. Looks like a great start.
Are you thinking ballscrews or belts? Considered epoxy-granite?
Just by way of resource, Midwest Steel has the best pricing on aluminum I’ve seen. Even with shipping. Used them to make a threaded table for my Shapeoko.
9mm - because they don't make a 9.1mm
You said "reloading BUILDING"...
Damn I want/need one of those. Hell, I am so looking forward to when I get to buy/build a place that can have separate shop, firearms, and desk areas.
Thank you! I greatly appreciate the offer!
This is going to get 5mm pitch ball screws. I don't trust cog belts enough for the tasks that I am hoping this will be capable of. Rack and Pinion would work as well, but china ball screws are plentiful, and should be good enough to get me to .001" accuracy. Some folks have had success getting to .001", and others have had to replace the ball nuts to get there. It's a learning process either way...
I am actually exploring filling the frame for vibration dampening, which is where epoxy granite really shines, but I haven't gotten there yet. Sand, pea gravel, and even heavy cutting oil are pretty common. Since this thing is already planned to come apart again, I figure I will run some tests and see if I need additional vibration dampening or not.
I appreciate the heads up on aluminum pricing. I will take a look at what they have to offer. I generally just run out to ALRECO in Brighton. All of my .75" blocks for my interface plates are just plate remnants from ALRECO, that are sold pretty inexpensively by the pound.
Maybe some ideas if you haven't seen them.. A lot of dudes will do a sand drain/fill plug setup for the cavities, to make it easier to assemble/disassemble. Some folks also 3D print plugs for the ends of the extrusions. I did some modeling, and I think lead shot in asphalt may be absolute king shit for vibration suppression. If you're not doing aluminum and expecting a high grade surface finish, I'd guess you might not need it for anything other than noise reduction. Naturally, keep that stuff off the gantry to improve your rapids.
ALRECO and K&K is nice for the small remnants, but Xometry has generally better and less beat up remnants boxes for cheap. There's also some dudes on ebay selling Fortnal and 7075 cutoffs. If you're bigger than ~foot by a foot, Midwest will beat ALRECO. Even with shipping. And you'll get new stock. It reflects badly on the local guys.
What are you doing for controller? Servo-wise, Clearpath like you mentioned is really nice. And for spindles, people really love those 2.2kw water cooled spindles on ebay
Last edited by Not_A_Llama; 01-04-2021 at 15:56.
9mm - because they don't make a 9.1mm
Is xometry local? I am looking for a new place to get drops from
You sir, are a specialist in the art of discovering a welcoming outcome of a particular situation....not a mechanic.
My feedback add 11-12 ish before the great servpocaylpse of 2012
They aren’t local - but the remnants box they sell is a decent assortment for a good price. Shipped Priority Mail, which is normally decent.
https://www.xometry.com/supplies/alu...61-t6-remnants
9mm - because they don't make a 9.1mm
The Great Kazoo's Feedback
"when you're happy you enjoy the melody but, when you're broken you understand the lyrics".
At least to start, given the "pre-used" condition of my extrusions, I am not going to fill the frame. Unless I use pea gravel, it will just pour out with any vibration. I'm more than confident in the ability to machine aluminum based on other similar, however lighter/less rigid, machines I have seen, even without filling the frame. Will it be as good as your Tormach, or a VMC? No. But I don't expect that.
There is a part of me that wants to play with filling the frame with epoxy granite, but I'm unsure how well that will work. If I don't explore that, I will likely go the sand route, with 3D printed plugs for each piece, like you mentioned. Weight is of little concern to me on this, as it will always live on the stand, and it's PLENTY strong...
Who knows, lots of possibilities... Lots to figure out...
When it's time to start making parts, I'll take a look at their remnants boxes. I honestly have very little interest in Fortal or 7075. 6061 can be machined just fine if you get it dialed in for the machine, and it has the benefit of still being weldable. Fortal (really just a private labeled 7xxx series aluminum) and really all of the 7xxx series shouldn't be welded. 7xxx "can be" welded, but if inspected it will fail for many reasons, the primary one being stress cracking within the 2 pieces, and the weld bead.
Control is going to be LinuxCNC with a Mesa Electronics 7i96 Ethernet board, fed into PrimoPal 390oz/in Nema23 steppers that I got from Torchmate, of all places. They had a sale on them that made them a good deal, and they come with 4-pin XLR connectors alrady installed. I am building a properly sized/rated unregulated PSU to drive the steppers and their drivers. If they are under powered when this is all built, and maybe just because I can/want to, I will likely upgrade to ClearPath servo's. Necessary vs bigger steppers? No, but more power, no lost steps, simpler control cabinet, and on the list goes.
Yep, I have one of the China 2.2kw Water cooled spindles that is going on this to start. However, I am really starting to ponder Automatic Tool Change capability, which if I am spending that kind of money, it's likely going to be bigger/more power.