Given the tons of excitement, involvement, and activity surrounding the awesome new LR4, all of which is totally warranted, and with several great build threads already underway, and with my own full-size rebuild mostly in the phase of “printing, gathering, laying ground work” — I’ve not yet started a build log. I seriously considered trying to limit a build log to only what tips or experiences are distinctive to my effort. I may not stay with that, but this first little tidbit seems to be unique to mine so far.
LR4 — Extending the JPlate wings by added length matching thickness of sheet material (i.e. hardboard or MDF) in combination with beveled edges of the wings.
The concept is simple: when designing front JPlate, tell @jamiek’s awesome web-based strut generator ( “Parametric Web Generator for LR4 Strut Plates” ) to extend the wings on the front plate by an amount roughly matching the thickness of your material, and then use bevel-cutting bit in a router or router table, to chamfer the edges of the wingtips, with the material removal happening on the backside that would face the steel tubes.
Pros: makes front look awesome, better protection from dust getting onto whatever is behind your front plate (board boxes, wiring, misting equipment, whatever).
Cons: none except adding a few extra minutes on making the front plate.
The bevel trick was done on my LR4 Beta and carried over to my LR4 RC3 machine. I’m again doing this on my full size LR4 build, although I don’t have accomplishment / pics.
PICS (LR4 Beta and carried over to my LR4 RC3 machine):
As mentioned elsewhere, although in my area the home improvement stores don’t carry 1/4" thick MDF or hardboard, they do carry products that match that, and in my case, Home Depot sells “wainscotting” that’s almost 1/4" thick and comes pre-primed in white. In these pics, the primed white is still showing (I did not paint them). The logo work is laser engraved (on my refurb 100W CO2 laser from OMTech):
The added wings were @jamiek’s idea, and the reason Ryan is calling these “JPlates” on v4.
Without the wings, there are larger openings between the plate and the tubes, allowing dust / chips to get behind the front plate. With the wings, the openings are smaller.
With my extended wings, made doable by chamfering to keep from colliding with steel tubes, the openings are practically eliminated.
I like the look. I don’t have any way to verify how much more effective they are over the regular size wings.
The new Y rail is now attached to the metal strut.
Because the metal strut’s top is narrower than the printed LR4 rail clips, and because a shorter footprint for the clip is needed to both get the screw hole located over the metal strut, and have the EMT itself located above the metal strut, I’m using a remix of the Y rail clip, similar to how I did for LR3.
NOTE: work in progress, yet to be tested, nonstandard. Use at your own risk.
When I took my LR3 apart, my core was still solid and good (no cracks or delamination), but my nylock nuts on the tool mount holes had lost their ability to lock, so instead of nylock they were nynot. That meant that lately I had to re-tighten the tool mount screws on every single job! Obviously, I am not reusing those nuts! LOL
Did you take your tool mount on and off a bunch? Just wondering. I used the same hardware from my old smaller LR3 for all 4 iterations of the beta and I didn’t have any issues with the nylocks not holding anymore. I am sure they have a lifespan to where they just wont hold anymore. Just made me curious if that was the reason for yours.
I did, primarily due to 1) on LR3 the router cannot be removed without loosening the mount screws, unlike the LR4, which can, and I love that, 2) I did lots of design / print / test iterations on projects that used the tool mount screws to attach, including the Kinematic Tool-less Quick-Change Accessory Holder
This time around, the very first thing I assembled was the gantry. Not sure why. Anyhow, the front Jplate is simply bare hardboard, painted with red acrylic paint, and laser engraved. Thanks @vicious1 for the cool V1 sticker!
I think he is at 1450mm to get a full usable 49” for MDF. Thats right at the same size as my full sheet machine. I can’t remember the exact number on mine
Based on consulting the calculator, and my virtual model of my table with the new machine on it, I arrived at a steel tube length of 1398. It looks right for my table. I will need to move the spoil board toward the X-min side by several millimeters, because the machine’s cuttable area is allocated more toward that side (as compared to my table design).
I did that on my small beta / RC machine. However, I did it in “not” the best way for testing. I did right from the first install, which meant I did not get a baseline cut without it, to have for comparison.
When it comes to trying to do “before/after” testing on this big unit, I’ve been dealing with sickness and hectic days and not much free time, and so I am minded to just go ahead and do them and leave the testing details to someone else. I’m sorry to be so less than ideal on my contribution to the project. I just have so much on me.
I ran it both with and without, And I did not see a measureable difference.
@DougJoseph I would suggest going without. And if you find you have flex you weren’t expecting then add them later on maybe. But I did not notice a difference with them in.
One of my challenges is that my spoil board of my torsion box that had my LR3 on it, is my reference surface for whether my new LR4 gantry is made without twist. The risks there are at least two fold, in that the two metal struts (Unistrut) could have been installed with a slight misalignment, creating a twist effect, and my LR3’s 1" stainless steel tubes could have had some sag at the last time the spoil board was resurfaced, meaning my spoil board could possibly have a concave curvature spanning from X-min to X-max.
In light of these two possibilities, I considered that testing the LR4 gantry assembly for “squareness” and flatness should not be done across the table X-wise or diagonally either, and so I felt my best odds were to check for flatness along the Y-axis direction, up against one side.
Given that is likely the closest to a flat surface of anything I have that is large enough (my granite slab I bought for a reference surface for making a Voron, is not large enough for this), it will have to be the best that I can do.
That being said, I’m thinking that pre-drilling into my EMT tubes and using the screws, will help prevent unwanted twist from occuring. I’m minded to go ahead and put them in.
I did go ahead and drill the EMT tubes and install the screws that lock the braces in place on the tubes. I have not tested whether the machine is stronger with these than without.
