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can't you just align the ends from the original table on the new table and use a transfer punch?
the cncfusion mounts are slotted for vertical adjustment so you won't need the pins anyways iirc.
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Hi Guys,
This is my first post. After lurking for a long time in the forums and seeing all the great work done by Hoss and others I decided to buy an X3 mill from Grizzly for CNC conversion. Got the mill on Monday and have already broken in the spindle and checked the flatness of the X bed (it is less than 1 thou over the entire bed).
I have a CNC fusion deluxe kit on order with a special modification. The X screw I will be getting will fit the longer 700mm x table that one can buy as a kit from Little Machine Shop (approx $250). I can benefit from the longer table due to my machining of 80/20 extrusions for my home robots. Here's the question:
I got my longer x table today but there are no tapped holes or guide pins on the table ends for attaching the end plates that hold the lead screw. According to Chris from Little Machine Shop this is normal and the holes need to be drilled and tapped. Anyone have some advice on the best way to line up the end caps before drilling? I worry that if the alignment isn't near perfect there will be binding in the X movement. One thought was to use a pipe clamp to hold the end caps while adjustments are being made. I would sweep the table over the limits until things felt smooth, then I would drill and tap the socket cap holes, install the socket cap screws, remove the pipe clamp, make sure the table still moved smoothly, then drill and install the guide pin holes.
Thanks,
Danh
can't you just align the ends from the original table on the new table and use a transfer punch?
the cncfusion mounts are slotted for vertical adjustment so you won't need the pins anyways iirc.
I'll still use the holes from the original table as a sanity check. By using pipe clamps during the alignment process I can ensure that the bed cranks smoothly from end to end before drilling. I will also be able to check the flatness with a DTI before drilling just in case it is way off and needs to be returned to Little Machine Shop.
I only have a cheapo titanium nitride drill set from Harbor Freight. Based on what I've read on the web I need to use a Cobalt drill bit meant for hard metals along with oil. Also wondering if my cheapo tap set from Harbor Freight will work ok on the steel table. So much for thinking the long table was a bolt on kit. I originally wanted to avoid the need to drill or tap the mill for a CNC conversion.
I'm curious to find out how flat this long table kit is. From what I read on the forums the table was discontinued at one time because Sieg had trouble holding tolerances. I'll post what I find with a DTI.
a butter knife and wine opener could drill and tap the table. lol
its not steel, its cast iron and soft as pig snot to drill and tap. if the table were steel it would resonate and vibrate like crazy I'm guessing.
Get yourself the 115 piece HF cobalt drill set when u can. use a coupon and you can have every letter, number, and fraction size up to half inch then buy replacements when they break, wear, our you maul the shaft by not tightening then down well enough.
everyone has their opinion, but HF crap is GREAT for starting out and breaking as you learn. the taps will work just fine on cast iron, aluminum and mild steel with the right sized hole, lots of rapid tap, and care. don't think I would even set one of mine on a stainless steel bar stock, but in a pinch they are okay.
I have a nice collection of taps ordered for jobs, but still find those useful now and then. I love the style tap handle that comes with those kits, but they crack easily so I picked up the same style from irwin and use it any time space isn't an issue.
remember when aligning- you only have to be really close, not "perfect", there will be some wiggle room with the slotted holes that are larger than the screws.
also- don't breath in the cast iron powder from drilling *cast iron*. not good for u I'm told.
Thanks for all of the cast iron advice.
I bought the X3 to replace an old Sherline CNC that gave out. At first I was going to get a TAIG but decided on the X3 because it was a significant step up in size and because of all of the cool mods I saw on Hoss' website.
I'm only used to working with wood, ABS, and light aluminum on the Sherline so the thought of upgrading my cheap HF tools to mod what I thought was steel on the X3 freaked me out a bit. I've also seen binding problems on the X bed of my Sherline and a cheap CNC router bed due to alignment issues with the lead screw and brass nut. Looks like if I'm careful along with the wiggle room of the X3 end plate cap screws I should be ok.
So I partially installed my X3 long table today and made some flatness measurements with a DTI from Harbor Freight that reads in 1 thou increments. I didn't do any drilling for the table end caps yet. I just adjusted the gibbs for smooth motion and moved the table by pushing and pulling it. I didn't want to do any drilling just in case the table was way off and I had to return it. The results were surprising:
With the DTI base attached to my Z column I positioned the DTI tip to the far left of my extended table and then swept the table about 24" to the opposite end. The readings were within 1 thou until I got near the edge which read 2 thou. This seems pretty good to me for a 24" swing and I was feeling good about the table. I did six tests with these 24" sweeps along different table depth positions (approx 6" depth) and got similar results.
The next test involved checking the table flatness by sweeping 6" from the front of the table to the back of the table. I did this sweep on the far left, far right, and table middle. I was surprised that my readings ranged from 1 to 2 thou from the zero position. I was thinking it should have been better, maybe something like a half thou deviation over 6". This newbie would like to know what you'll think about this accuracy? I plan on keeping the table since most of my machining will involve pocketing which goes through the entire part, ie: plates for mounting NEMA 23 motors and machining pockets through 80/20 Aluminum.
Thanks,
Danh
ImagineRobots.com
It could involve the mounting of the machine on the bench. It may not seem like it but the base of these mills can twist/bend pretty easy. And chances are this is because of the Y ways/guides & not the table ( or maybe even the saddle itself).
Using a machinist leave to set the base up may help to even out all of the differences. Ofcourse it may be the table itself to but starting from the base and workng up might help.
Also if its in the table and the ends are high it may settle after a little time.
BTW, what are you going to do with the old table? I have a need for a small table for a machine I am working on.
Jess
GOD Bless, and prayers for all.
I put the old x table back on and there is about a 1 thou improvement in flatness deviation during sweeps in the y direction. I'll live with the 2 thou flatness deviation of the extended x table for now.
I plan on using the old x table and unused parts during the CNC conversion to build another semi X3 machine. For around $500 in additional parts from Grizzly, I can get a fully functional X3 minus the spindle head.
Thanks,
Danh
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