Urb's first attempt at the JGRO

[jckstrthmghty]

Been lurking around in here for a few months and I actually got around to starting my very own table. Originally I was going to make the buildyourowncnc design due to it's simplicity of construction but I opted for the JGRO design after much deliberation. I think the buildyourown is a excellent design for those new to fabrication but I wanted a bit of a challenge since this was more a hobby than a need. I did however order some parts from buildyourown which I am using for the JGRO version.


Just in the first few pieces I have learned so much. I have a decient pile of scrap mdf (mistakes) to show for it. Most of the work I have done to date is jigs and guides.

So one picture for now. I won't be able to get anything else done for a month or so due to holidays which is probably for the best. It'll give me time to work out some of my own ideas I want to incorporate.

Things I have learned so far.

1. Read and understand before you build.
2. A drill press, router, and a mitre saw are your freinds.
3. Cross dows make for strong joints.
4. MDF is nasty stuff when you take a router too it.

I think there's alot more I have learned but the MDF dust is starting to affect my ability to stay conscience.

Please feel free to make any comments/suggestions. I could sure use them.

[Glidergider]

Jack,
You're on the right track. I feel your pain with the mdf dust. I've got your solution right there in your back pocket too. Go to Harbor Freight and pickup a 2 hp dust collector. YOU WON'T BE DISAPPOINTED!!!!! It's a must have tool. Get the $45 hose kit too. I'm not kidding, you will love the result. Hook it up to all your tools.
dust collector:
http://www.harborfreight.com/cpi/cta...emnumber=45378
hose kit:
http://www.harborfreight.com/cpi/cta...emnumber=93601

Your z axis looks good. Keep up the good work. The JGRO is a great cnc router. I love mine.
Dave

[jckstrthmghty]

Just got back from vacation and the first thing I did want get back at the build. I've gotten alot completed in the last 2 days most important of all is pictures.

I have to say I was a bit sceptical about tapping MDF but after creating the guide blocks I'm amazed how strong the stuff is. I realize you can't torque the screws hard but MDF will certainly do the job. Same goes for gas pipe. I didn't think they would be percise enough but they seem to be well within acceptable tollerances. Saves me some $$ instead of buying percision ground rod.

I'm going to move onto the router clamps and order up some lead screws. J from buildyourown recommended buying the best leadscrews I could afford so I'm going with 1/2" percision ground acme rod and I'll pick up some anti-backlash nuts from dumpstercnc.

Hopefully I'll have some updates within the next week or so but I feel I'm going to slow down as the larger parts of the project are next.

Glider. I appreciate the advice. I've done some research on dust collection systems and I'm going to pick one up this week.

[matt888]

Nice. I'm planning on building the aluminum angle sliders this weekend. Did you use a table saw to cut the notches in the aluminum angle? How did you secure the aluminum to get the cuts done?

[jckstrthmghty]

Originally Posted by matt888 Nice. I'm planning on building the aluminum angle sliders this weekend. Did you use a table saw to cut the notches in the aluminum angle? How did you secure the aluminum to get the cuts done?

Actually I used a bandsaw to make the notches then used a handfile to flatten them out. I just held the aluminum angle flat against the mitre guide and estimated the depth. I think clamping down a depth guide would've helped alot. My first attempt I just used a file but that was alot of work. Even notching the aluminum with a hacksaw would be a major time saver.

Goodluck with your skate bearings.

[jckstrthmghty]

I read somewhere on this forum that you make a "ugly" cnc router first so you can make the better one later. This is becoming very evident to me even in my early stages of my router. I don't think the JGRO is a bad design by any means but I'm aware of the flexing issues expecially when you expand the size of the design. Additionaly the cutting area on the JGRO seems small.

So I have a question for those who have started with the JGRO and used that as a platform to build a Joe's version. As per the plans provided here is the cutting area of the JGRO suffice to cut the parts for the Joe's version without any modication?

As for my JGRO I plan to buy the base assembly material tomorrow and before I do any cutting I wanted to know if I needed to extend the cutting bed.

Edit. Seems the way to go is to break up the cuts. This will be interesting once I learn how to use the cnc router... if I ever finish the thing...

[rdhopkins]

I used my JGRO to cut out all the parts for Joe's version although I did downsize my Joe's CNC by 10% to allow it to fit in the space allocated for it in my garage.

As far as I can remember, the majority of the parts could be cut out without problem on the JGRO. There were a couple of parts such as the long parts of the base torsion box that needed to be cut in two parts and glued together. I also remember laying one part out diagonally over the JGRO bed so it would fit!

[jckstrthmghty]

Good to know that most the parts for joes can be cut using JGRO. It's taking me forever to measure and cut with hand tools for this build. It'll be a relief to let the machine do the hard work for me on the next build.

I've gotten some work done on the base support. I've decided to modify the design a bit to allow support for the y rail later on. I extended 2 of the inner runners and increased the stock to 3/4 from 1/2 mdf to allow me to attack a support structure close the center of the rail where it will sag the most. Hopefully the pictures will convey the general idea.

[jckstrthmghty]

Got a little more work done tonight which brought up a few questions.

1. My bearing has a OD of 1.125. Should I just get a 1.125 spade bit for the mounting hole? I wanted to press fit the bearing into place but I don't know if they make a spade bit slighty smaller than 1.125. What have you guys done to fit the bearings?

2. Are 305 oz motors overkill for this build?

I'm starting to get a bit excited as I get closer to building the gantry. I should have most of the base completed tomorrow sometime. As I look back on the build to date I'm glad I started with a JGRO design. Although I think for some it would be possible, it would've been near impossible for me to build Joes or any other build with hand tools.

[Glidergider]

That's good progress. Your 305 oz is not to big. I use 425. It won't be long now.

[jckstrthmghty]

Just wanted to post some progress I've made. I'm still working out how I will build the y axis support. I really need to build a stand for this thing rather than using a cardboard box.

Ordering lead screws next.

Glider. Great! Maybe I'll go with bigger stepper motors too.

[jckstrthmghty]

Well it happened and alot sooner than it thought it would. One of my y axis adjustment blocks gave out as I was setting up my rails. I'll be heading out tomorrow to a local plastic shop to buy some acetal. I have a question. I've read about some people using 1/2" material so would it be ok for me to as well or should I just buy 3/4" stock?