What's your favorite JGRO upgrade?

[nuplowboy]

OK, so I'd like to have folks post their favorite improvements and upgrades to the JGRO router design. I am weighing the cost/benefits of building a brand new (larger, faster) machine similar to a Joe's Hybrid (except more like a 2'x4') or just upgrading my existing JGRO router. Ideally, I'd build a new machine, but as I start to add up the costs, I'm thinking I may need a "plan B" to keep the "finance comittee" happy.

Here's what I have to work with currently:

- JGRO router build mostly to specs
- Hobby CNC Pro 4-axis driver board
- Hobby CNC 130 oz stepper motors
- 24V power supply
- Burnt out Dremel "spindle" (failed the last time I used it)

I've considered purchasing a set of 205 oz steppers to add some beef, especially if I was to build a new machine...

For fabrication capabilities, I can handle all the usual hobby CNC things, including welding (I typically prefer metal fab over woodworking). I also have a backyard aluminum foundry to help with odd-shaped parts.

Please post upgrades you've done/seen and liked. It can be links to other threads/posts or a pic of some small tweak you might have made to your JGRO along the way. Anything that'll increase the speed/accuracy/stiffness/etc of the machine as a "Plan B" vs building a brand new router.

Thanks!

[datacop]

I've just finished my machine.. I've got the Hobby CNC 4Axis Pro kit with the 305 oz motors.. I'm quite happy with that..

I can already tell though, my first upgrade for this machine is going to be doing away with the 1/4 20 all thread and get some faster screws. As far as spindle goes.. look at the Bosch Colt palm router. I'm quite pleased with it..

[nuplowboy]

Glad to hear that you're happy with the Bosch Colt. I've been eyeing it as a possible spindle for a while (like the variable speed that adjusts to load), especially for the JGRO sized machine. If I went larger with an all-new (and maybe all-metal) router, I'd be tempted to go with a full-size router for the 1/2" capability...

I would agree with the 1/4-20 screws being painfully slow. For a JGRO upgrade, I've thought about 1/2-8 2-start (1/4" lead) which should let me move at 100 IPM even with my 130 oz steppers (can go 20 IPM with the 1/4-20 screws) Most of my machining is foam for casting patterns and some MDF or oak. Of course, with an upgraded or new machine, I'll be very tempted to start diving into a chunk of aluminum plate or something...

[dustin1706]

1/2" acme and HDPE adjustment blocks.

Some Y rail support would be nice as well, but I haven't got there yet.

[nuplowboy]

Yeah, still thinking about supports for the Y rails... Haven't come up with anything real clever yet.

Forgot to mention in the original post, but I've already got the adjustment blocks covered. After splitting out the first MDF one, I jumped straight to casting aluminum blocks for all of the axis. The blocks are stout, just need to stiffen up those Y-rails...

Has anyone done a dual leadscrew on the Y axis for one of these machines? Or rearranged the Y-axis bearings to increase the width/tightness?

[Rotax91]

Instead of Y supports, why not just go to a solid 20mm linear shaft? Can get them cheap enough off ebay and other sources. Just a thought..

[DeadTom]

Here are my X axis supports, these are fashioned after what Jason Marsha did on his build a few years ago.
I am running 5/8" - 11 all-thread for all three axis. Each lead screw is kind of pretensioned as each end has a bearing and a nut retaining the screw from moving forward and aft; then the stepper motor is mounted to the mdf standoff, the 1/4" stepper shaft and the 5/8" all-thread are joined by Lovejoy couplers.
I have also changed the base and table layout some to use angle iron for the table, making it much simpler for myself.
Tom

[MrWild]

I did a lot of reading before i started my JGRO. Before building the base I drilled pass holes for the Y (X?) axis supports and used 1/4-20 all thread as the cross ties. Make sure to run nuts down to the base so the all thread is stiff and doesn't bounce back and forth through the base.

1/2-10 ACME, but think I'd rather have gone with two start than single.
DUST BOOT! Lord what a mess. It for sure needs a dust boot.
285ozin X and Y with a 425ozin Z. G540 with 48v PS
PAINT If it isn't industrial gray, it isn't a true machine.

I need better shaft supports yet, and better motor mounts. Even so, I can get it to rapid as fast as 180 IPM. Due to the crappy motor mounts bought, it still isn't spot on though.

[Rotax91]

again this goes back to my question above, why not just go with solid shafts instead of gas pipe? Can get these pretty cheap. Wouldn't need to do anything with supports then.

http://cgi.ebay.com/20mm-CNC-Router-...item5d249e27d4

[guerd87]

You will still need support. Just because they are solid does not mean they wont flex.

For a straight out of the box solution use these: http://cgi.ebay.com/Linear-CNC-Route...item19b228db8c - You will need the correct length for your machine though..

But, they are expensive.

[Rotax91]

Thanks for pointing that out. Being that they are solid, I just assumed they were too tough to flex. I'm still planning my build so it's good to know all this beforehand. I can see that's why most people go with gas pipe, especially if you have to support it anyway.

Ya, I've seen those supported shafts before on ebay, very expensive. That price is just for one.

[dustin1706]

I've kinda had my eye on these as a MUCH cheaper alternative to the one piece supported rod and vxb bearings/blocks

http://cgi.ebay.com/ws/eBayISAPI.dll...tchlink:top:en