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Grizzly G0704 Cnc Conversion

cozmogeek

Active Member
Active Member
#1
I got a grizzly g0704 yesterday and am planning to convert it to cnc as soon as I can. I don't have any metal machining experience so this should be very interesting. Stay tuned for pictures and videos.
I got Hoss' conversion info and hope that will be enough for me to figure this out.

Tp4JNDS.jpg

3D printed temporary stepper mounts
coP71rk.jpg
 

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TomS

Active User
H-M Supporter-Premium
#4
I got a grizzly g0704 yesterday and am planning to convert it to cnc as soon as I can. I don't have any metal machining experience so this should be very interesting. Stay tuned for pictures and videos.
I got Hoss' conversion info and hope that will be enough for me to figure this out.

Tp4JNDS.jpg

3D printed temporary stepper mounts
coP71rk.jpg
I see the word "temporary" in your post. Are you using these mounts for set up?

Tom S.
 

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cozmogeek

Active Member
Active Member
#5
The theory is to use the plastic mounts to get it cnc'd faster then use it to make the metal mounts


Sent from my iPad using Tapatalk
 

TomS

Active User
H-M Supporter-Premium
#6
The theory is to use the plastic mounts to get it cnc'd faster then use it to make the metal mounts


Sent from my iPad using Tapatalk
I hear what you are saying but will the plastic mounts be rigid enough? I'd be concerned that the mounts will distort when you load the motors during a cut. A couple of implications would be inaccurate parts and possible damage to your motor couplings and/or ball screws.

Just my thoughts. You may be successful. Let us know how it turns out.

Tom S.
 

lcvette

Swarf
Registered Member
#7
I don't think it will be a problem unless he is trying to take really heavy cuts. Should be plenty fine for making the parts out of metal for the conversion which won't need super critical tolerance.

Good luck, its a long arduous journey but worth it in the end!!

Sent from my XT1080 using Tapatalk
 

jkcrum

Iron
Registered Member
#10
Just curious, if your Grizzly has acme screws like mine, will you convert those to ball screw if going to CNC? Or can CNC programs take the slack into account and compensate to get the accuracy you want?
 

JimDawson

Global Moderator
Staff member
Director
#11
Or can CNC programs take the slack into account and compensate to get the accuracy you want?
Under a few conditions backlash compensation works, but not many. Cutting a circle for instance, it won't work. It will work for doing a hole pattern, but in general it will not work when continuous cutting. The only real way to get accuracy is to have zero backlash.
 

TomS

Active User
H-M Supporter-Premium
#13
The ballscrew upgrade is really expensive. I want to see how it does with the leadscrews first.
Look at what Linear Motion has to offer on eBay. Their pricing for ball screws and nuts is very reasonable. I spent about $125 for three pre-machined ball screws with nuts, and three each fixed and floating bearing blocks about a year ago when I converted a PM-932. The contact person is Chai and his customer service is very good.

Tom S.
 

brav65

Active User
H-M Supporter-Premium
#15
Look at what Linear Motion has to offer on eBay. Their pricing for ball screws and nuts is very reasonable. I spent about $125 for three pre-machined ball screws with nuts, and three each fixed and floating bearing blocks about a year ago when I converted a PM-932. The contact person is Chai and his customer service is very good.

Tom S.
+1 on linear motion and Chai. I got 4 ballscrews and nuts along with a spindle motor and linear bearings. Good guy, and if you buy direct he will give you an additional 10% over eBay prices.
 

cozmogeek

Active Member
Active Member
#16
+1 on linear motion and Chai. I got 4 ballscrews and nuts along with a spindle motor and linear bearings. Good guy, and if you buy direct he will give you an additional 10% over eBay prices.
Thanks for the heads up about the discount. I'll have to look into it soon.
 

cozmogeek

Active Member
Active Member
#18
I got the X and Y done and everything wired on Monday since it was a holiday.
I just got my Z axis done. I used the 3d printed direct drive nema 23 mount. I used linuxcnc and the jog keys on the keyboard (arrows) to make those aluminum standoffs for the Z motor. That's the first thing i've ever milled...yay!
Now I need to spend some time getting linuxcnc configured. I got a USB pendant too that I need to get setup.
VkbDYS6h.jpg
13i5ypPh.jpg
 

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cozmogeek

Active Member
Active Member
#20
I have made some more progress on this. Last week I ordered the ballscrews.
I tried tracing text with a 1/8" endmill and the results are pretty ugly:
LsBeBWvh.jpg
You can see the backlash in the results. When drawing the O and D the start and end of the letter don't line up. This was before I realized that the bearing wasn't seated all the way so I had a ton of backlash. After I cut this I measured and it was .04" (LOL).. I tightened it up correctly and got it down to .003"
So then I setup the backlash compensation and tried an engrave operation instead and it was much better other than my board not being straight.
7VfZENbh.jpg

Over the weekend I made the motor mount standoffs and the X axis mount (manually using the jog controls on the keyboard):
usMdM3nh.jpg
Tonight I plan to replace the 3d printed X mount with this new one.

The Z axis mount is different for the ballscrews than the leadscrew version so I'll have to wait for those parts to arrive before I can replace it. I'm not sure about Y yet. It is more complicated since it has the spacer with the holes for the bearings.
 

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MontanaAardvark

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H-M Supporter-Premium
#22
I just posted about a conversion project like yours a few days ago (last Saturday?) on the Grizzly board. I guess I should have put it here.

I'm also doing the phase 1 from Hoss, with the big difference being I cut all the metal parts first. I don't have a 3D printer, but I have a CNC Sherline(/A2Z CNC) system. I cut everything on that.

But your motors, breakout board from CNC4PC and the rest sure look very familiar. Tonight I was going over how to wire up everything so the limit switches and the Big Red Switch work with it. And I think I'm on the way to eBay to look at those ballscrews.

My Sherline has the A2Z upgraded XY base. The leadscrews are 4TPI, Teflon coated Kerk screws. They do have a few thou of backlash, though. I was also thinking of looking for other Kerk products.


Bob
 

MontanaAardvark

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H-M Supporter-Premium
#23
Can someone give me a link to Linear Motion on eBay?

When I searched for that name on eBay, there was no result. I eventually made it one word, and now there are four. None of them have anything up for sale.

Needless to say, I'm having a bit of confusion.

linearmotion ( Feedback Score Of 80 iconBlueStar_25x25.gif )
2 years 3 months AZ,United States

Close matches:

Member id linear-motion ( Feedback Score Of 10 iconYellowStar_25x25.gif )
8 years 6 months Germany
Member id linearmotion01 ( Feedback Score Of 882 iconPurpleStar_25x25.gif )
11 years 0 months Germany
Member id linear_motion ( Feedback Score Of 63 iconBlueStar_25x25.gif )
9 years 6 months MN,United States

From what was said, I assumed if they weren't in the US, they'd be in China or somewhere else in the Orient.


Thanks,
Bob
 

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sbx

Active Member
Active Member
#24
Bob - Try Linearmotion2008. I think the guy's name is Chai. And I do think he was in China. Just based on the research I've done for my PM25 (research ongoing). Not an endorsement, just what I remember. Hope that helps.
 

MontanaAardvark

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#25
Bob - Try Linearmotion2008. I think the guy's name is Chai. And I do think he was in China. Just based on the research I've done for my PM25 (research ongoing). Not an endorsement, just what I remember. Hope that helps.
Thanks for the suggestion, but that doesn't show up either. I think I tried every variation of spacing.

Maybe they've closed their eBay account?

Edit to add: I just sent an email to that address farther up the thread. I'll see if I get anything back.

Edit yet again to add: Hoss' DVD says the name on eBay is linearmotionbearings. That doesn't show up on eBay either.
 
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brav65

Active User
H-M Supporter-Premium
#27
Thanks for the suggestion, but that doesn't show up either. I think I tried every variation of spacing.

Maybe they've closed their eBay account?

Edit to add: I just sent an email to that address farther up the thread. I'll see if I get anything back.
They are listed under linearmotionbearings2008 and have at least 100 listings. I posted Chai's email address to which you sent the email. Keep in mind the time difference when waiting for a response.
 

MontanaAardvark

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H-M Supporter-Premium
#29
I just heard back with an informative email, and their store is:

http://stores.ebay.com/linearmotionbearings

I'm not sure why it wasn't showing up in my searches, but maybe because I was searching by seller and not by eBay Stores?

The next thing on my list is to build my controller box, and maybe a computer. My Sherline is running Mach3 on a 1 GHz XP box that's cut off from the outside world, with nothing on it except Mach3. Not sure what else I can put together in a hurry.

But before that, I've got to finish painting the kitchen!


Bob