# My G0704 CNC upgrades and conversion



## vinnito1 (Dec 28, 2018)

Hello all,

I would like to share my CNC conversion with this site. Over the last 1.5yrs i've been looking at all the different conversion done with Grizzly and Precision Matthews bench top mills. I choose this site to share the build because I enjoy the  atmosphere and all types of projects shared by its members. 
This mill wasn't my first choice for a bench top conversion, but I got a great deal on it.....free. Well not entirely free, i had to barter  my time in exchange for it. I've acquired alot of parts over the last year and even made a few parts at my local Makerspace for the conversion. Now I plan on tackling a major upgrade...changes to the a column. I won't provide too many details at this point because well...its going to take alot of work to make it right and i'm still thinking through the steps on how to make it. Here is a few pictures of what i'm planning.




You can see the size difference between with the G0704 column assembly and the one i'm planning on doing . I know doing these upgrades doesn't make sense but who cares . Hopefully I can learn a lot on machining. I've spent way too many hours in front of a computer designing stuff so now its time for me to start making them. I was able to pick up the material today and hopefully soon I will make start machining



Progress and updates will be a bit slow because I can only spend a few hours a week machining parts and its about a 40 mile drive to the local makerspace in Dallas

Thanks and I hope you all enjoy the build
V


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## tweinke (Dec 29, 2018)

Slow and steady will get it done! It should be a fun learning process. Please do keep us up to date.


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## vinnito1 (Jan 10, 2019)

New goodies from Christmas to help with the build!  I purchased a 550 mm long 1605 ball screw from automation4 less and 580 mm long HGW20 Hiwin linear rails from Motion Constrained. These should give me a little more than 15" in travel in the Z direction.  I was planning on using HGH20 Hiwin carriages, but Motion Constrained called me to let me know they are out of stock for another 2-3 months. This was not a big deal because I can easily adapt the design to use the HGW style carriages. I did look into  using RGH15 Hiwin linear rails, but they were quoted 3-4X higher in price than the HGH style. Ouch!



 I now have a Shars granite square to help aligned everything when its all built up. The shipped inspect sheet states the perpendicularity between the 90 deg surfaces is  .00008"/6" which is more than good enough for what I hope to achieve.


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## tweinke (Jan 11, 2019)

It will be interesting to watch your progress.


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## vinnito1 (Jan 12, 2019)

tweinke said:


> It will be interesting to watch your progress.


Thanks. I am planning to start machining parts early next week. Hopefully everything works out


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## BROCKWOOD (Jan 13, 2019)

Looking forward to your updates! I must ask, though, what is the local makerspace in Dallas?


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## vinnito1 (Jan 13, 2019)

BROCKWOOD said:


> Looking forward to your updates! I must ask, though, what is the local makerspace in Dallas?



Me too, I hope it all goes relatively smoothly . I'm not quite sure what your asking. If you are asking where is it located, it is located in Carrollton just northeast of DFW airport. If you are asking what is Markerspace, it is a place where a local community of builders are able to get access to equipment to complete their projects. I am fairly luck that the Dallas chapter has a well tooled machined shop area for me to be able to complete my project. The big stuff they have is a Bridgport Mill with DRO, 2 larger lathes, and even an older Haas CNC ( wish i had training to use it though ). Attached is the link for more info.


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## BROCKWOOD (Jan 13, 2019)

vinnito1 you have answered my question. I lived in the D/FW metroplex for 9 years & still return on occasion. This sounds like a really cool space to have! Thanks for the link!


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## vinnito1 (Jan 14, 2019)

I was able to spend some time in front of the Bridgeport today milling a slot into the right side column piece. The left and right side column pieces will have slots milled into them to help locate the pieces before being bolted then welded together. A little thought needed to be put into how I was going to mill the slot since it was 3-4" longer than the table travel on the Bridgeport. Luckily, I talked to a machinist at work last week who let me borrow 5/8' precision dowel pins that could slide into the T-slots. This allowed me to slide the work piece without losing my Y axis origin. I used several 1-2-3 blocks to re-establish the X axis origin. Once I get the center piece cut to final length, I'll wont know how good using the 1-2-3 blocks worked out. 



Cutting of the slot


Work piece unbolted from the table and slid to the left end of milling table. Using 1-2-3 blocks and edge finder to re-establish X axis location. I used a 0.0005" dial test indicator to check that the milled slot was parallel to X-axis by less than 0.001" before fully tightening the clamps



Completed slot.

I thought that I would be able to complete machining 2 parts today, but I barely made it half way with this one. It was all worth it when I did a test fit with the mating center piece. It just needed a little finesse for the center piece to snugly into the slot


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## vinnito1 (Jan 19, 2019)

A small update, I completed rough machining on 1 of 2 vertical uprights and started machining on the 2nd vertical upright. Here are a few pictures sharing progress with everyone



This is the completed machining of the first vertical upright. After assembly and welding, I plan on doing a finish machining pass to remove any warpage that occurred during welding on critical surfaces, followed by scrapping in the surfaces the linear rails mount to and the lower piece that attaches to the mill base. Does anyone think I will get a large amount of warpage welding 1" thick 1018 steel together assuming I don't get too much heat in the metal. I'll be bolting the major parts together before welding. My plans are to have up to 0.050" of material machined off to get the important surfaces trued up before scrapping



Cutting the 2nd vertical upright to length. 36" long vernier calipers to make measuring a 32" long piece of steel simple.



After thinking about a better way pick up the slot location after sliding the work piece down the table, I just wrote down the values on the DRO, used an edge finder to get the location again, and then enter the values back in the DRO. This is a much simpler and better way to do this IMO than how I did it on the 1st part. I also got a 4 flute 0.655" stub nose carbide end mill from my father. This made machining the slot go soooo much quicker vs using a 1/2 HSS end mill


First of many test fits. Still have lots more machining and head scratching to do, but seeing this put a smile on my face.


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## vinnito1 (Feb 2, 2019)

More progress. I machined and completed the gusset plates that are intended to increase column stiffness in the X direction. They will eventually be bolted down to the base by additional holes  located away from the 4 center mounting bolts



Taking a skim pass to bring to final dimensions



Facing the ends to also bring to final dimensions



Measuring to confirm I can do simple math with a calculator and DRO 



Set up to cut the same 7 degree angle on 2 different pieces



Two completed support gusset plates 



New column in its current state.




Size comparison difference


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## BROCKWOOD (Feb 3, 2019)

I had to look up the G0704 to get an idea of what you are beginning with. Major improvement in strength! I have a similar mill on my combo & am glad to find you making these improvements.


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## vinnito1 (Feb 3, 2019)

BROCKWOOD said:


> I had to look up the G0704 to get an idea of what you are beginning with. Major improvement in strength! I have a similar mill on my combo & am glad to find you making these improvements.



Everyone says the column is one of the weakest stuctural links in the G0704. When doing my initial modeling to do a CNC conversion, I was surprised how thin the walls are in the casting. If I'm going to spend the time to do it, might as well over do it


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## vinnito1 (May 7, 2019)

Well it has been a few months from my last post. I have been patiently saving for the servo motors. I decided to go with DMM 400W Nema 23 servo motors on the X/Y axis and a DMM 750W Nema 34 servo motor on the Z axis. These will be power by the DMM DYN2 servo drives with 60V power supplies. I have to give the DMM customer support a big thanks for helping me out. IMO....they went out of their way to satisfy this customer.

 Seeing what others have done on the forum, specifically macardoso and shooter 123456, I went ahead and got an Allen Bradley 2kw/5000 rpm spindle servo motor and 2kw servo drive. I want to thank macardoso for helping me out trouble shooting the drive and his support to me. I don't have much to show for it yet, but i'm getting there slowly


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## vinnito1 (Jun 17, 2019)

I have been able to do machining over the last month to have completed ( almost) 2 parts that will be used on the new column. The first is the adapter plate to attach the spindle to the column. I decided to enlarge upgrade the size of bolts used to secure the spindle by going with M12 bolts vs a mix of M10s & M12. I'm using studs right now but may change to bolts down the road. I just have to drill and tap a few more holes for attachment of cable routing clips, covers to protest the ballscrew/linear guides from chips and do finish pass on the top side of the adapter plate. I'm working on using a 3D printer and thin sheetmetal to make way covers found on VMCs. I didn't leave enough space to used bellows and don't want to use rubber strips. With my design, I can get ~10" travel that compresses down to less than 3". Once I have the test parts printed, i'll share my concept with everyone.


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## DavidR8 (Feb 9, 2020)

This is a great build thread. 
Any updates to share?


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## vinnito1 (Feb 10, 2020)

Unfortunately, I've haven't been able to spend any time on this project. Family comes first, so when everything settles down in a few months I'll start making progress again


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## DavidR8 (Feb 10, 2020)

I totally hear you there! 
Family must always come first. 
Glad that you’re still on the project. 


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