Building up gantry, test fitting tonight. Hopefully Saturday I will get the gantry mounted and z-axis mounted to the gantry.
Let’s hope your wooden frame is more rigid than mine turned out to be. Because I just spent the past week reinforcing mine with more steel bracing. I’m hopeful that what I did this time around is enough. But I still have to put the rest of the machine back together in order to find out.
I have a feeling ill be adding tons more bracing to my machine. Its all 1" & 2x1" 8020 frame. I am kicking my self for going with the slides that go with them. They work well for the slide on the gantry and for the z axis but not so much for the gantry itself.
@Paul_Frederick I am using 3/4 mdf, and made thr top of the gantry as a box hopefully stopping any flex; @Bryan_Barnes_BBmech7 - I also used a 1 1/4 steel brace on the bottom of the gantry for extra strength. Hoping to take all the experience of this forum / builders to avoid prob k ems, so thanks for feedback!
@Bruce_Lunde
I used inch and a half leg, eighth of an inch thick lightweight steel angles in my corners. I found that was totally inadequate. So on the other side I put 3.5 X 4 three eighths inch thick heavyweight angle brackets. I’ll see if that beefs it up enough. Right now I’m hopeful, but I suppose I’ll see. My machine is totally different than yours though, so my experience has no bearing on you at all. Experience is what we gain by doing things ourselves. So good luck to the both of us I guess?
@Paul_Frederick I totally agree the experience has been invaluable. I started with my first design almost 6 years ago with a very small format using cold rolled steel rods all thread to drive and caste the part of the machine in poly resin. 
What a sad disappointment that was. Completely unstable and only marginally accurate. I have since put in almost 3 years in a mechanical design position where we design and build machines all day every day. It has also been an invaluable experience.
@Bryan_Barnes_BBmech7
So far my first design has been shaping up to be a sad disappointment too. I still have not gotten it back to the point where I can run it yet since I reinforced it some more though. Accuracy is where I am having some shortcomings myself too. I have a pen in the machine when I run it, and it cannot accurately reproduce this one test pattern to my satisfaction so far. Here is an early attempt I did using a pencil
I am now two iterations away from that machine. I do not have a picture of the second attempt, or the third quite yet either. Maybe tomorrow I might have things back together, and run again? I’m not holding my breath over here for that though.
I don’t even have a picture of my machine since I did the second modification on it yet. If it still doesn’t work I’m not taking a picture of it then either. Oh well, try, try, and try again, I guess? After that the whole thing is hitting the bonfire here.
@Paul_Frederick
i know the feeling. I’ve just recently gotten mine moving what looks to be good but have found out recently that my awesome deal on motors turn out to be garbage. 18mH inductance doesn’t move very fast. speed assided ive found that i have too much drag on my gantry and have no repeatability on that axis. sometimes its within .1mm others its off by almost 1mm… so i have some thoughts on a BB bearing setup that i can make easily without trashing the whole design. if this goes south i think im gonna simply dismantle it and go to work on building a delta style printer instead.
@Bryan_Barnes_BBmech7 The X axis on mine completely loosened up on me last night. When I made the machine I did not take enough care to make the Y axis gantry square enough to hold the bearings for the X axis square. Before I attached the lead screws it seemed OK when I pushed the gantry back, and forth, but running the machine it can drive itself out of alignment. So now I can either make some kind of an elaborate mechanism to adjust those guide bearings with, or make my machine a fixed gantry model, and have a moving X axis. Decisions, decisions.
I also toyed with the idea of completely scrapping this whole machine, and making something else. But after a while I came up with a vague plan to perhaps save two thirds of it? In hindsight I can see the basic flaw in my design. Each axis depends on the accuracy of the other too much to make it practical to build. There are even some issues between the Z, and Y axis, but I was able to rectify those with some shims.
There is no easy fix for my X axis quandary that I can see though.
@Paul_Frederick @Bryan_Barnes_BBmech7 did you guys use dual y-axis steppers or single Y stepper? I am wondering if mine will work well or not with the single lead screw, but determined to give it a go. It is fun in the workshop, so if I have to go back and modify, I will.
@Bruce_Lunde I use dual Y drives but the layout of my machine is not typical due to how I made my linear guides, and where my Z axis is in relation to the guides. My Z axis does not overhang the Y carriage, but rather rides through the middle of it, for greater support. So I put my lead screws outside of the Z axis, on both sides of it. I was looking for a design with more balance than popular configurations.
@Bruce_Lunde I have a single motor for each axis the X has a shaft that reaches through the length of the gantry and has a pulley on each end so there is no binding or uneven/ mis-timmed motion. Y axis has one motor mounted vertically with a belt running the length of the gantry and the loose ends are fixed to the slide. Z axis is driven by a 3/8-16 threaded rod. Someday I’ll add photos here to see. I don’t have any since i cleaned up the wiring (or the work space :D). My design intent was to keep cost minimal and simplify as many of the components required as possible. my aim was something that could be made with minimal tools mostly being a drill press, paper templates, band saw/ hack saw, ect…