HF 8X12 CNC Conversion starting...Need Help

[ronncat]

Good idea for an idler JT. Unfortunately, by the time I read it I had already placed my order with SDP. Needed some spare belts and they're only about 6 bucks apiece. Milled the prototypes for apron extensions. My math was off and I missed centering the ballscrew holes by 25 thousandths. Enough to make me want to remill them. So off to the supply company for more stock tomorrow. I'll try to have the Z axis done in a couple of days. Spent all of yesterday ordering everything for the controller box. While I wait for the UPS man to deliver all that I think I'll start on the hall effect home switches.

[ronncat]

Today, I remilled the apron extensions/ballnut holder for the Z axis. Here is the left side to which the ballnut attaches.



Then with the ballnut bolted on :



And finally mounted onto the saddle:



Lastly, the right side finished and attached:



Note the large indented cups on the outside of each extension. These will act as the pilots for the ballscrew covers. I just need to cut out a chip guard to seal the bottom and the small area exposed on the backside of the screw enclosures. With the ballscrew covers all in place, the screws should be well protected from chips and moisture. Finally, I'll get to try out my blast cabinet with some glass beads I picked up. I think I'll polish a couple of pieces and give the rest the blasted finish.

I am considering mounting my Hall effect home switches within the enclosure as well. They can be triggered by a magnet that I can embed into the framework of the lathe. Since there is almost a 1-1/4" difference between how far my 3 jaw and 4 jaw extend out, my home switches will have to adjust depending upon which chuck I am using. Will have to ponder that one for awhile

[ronncat]

Edit my thoughts on the home switch. What I should have said is that I will need to have two sets of soft limits for the Z axis. One for the 4 jaw, and one for the 3 jaw that extends out much further. I also could consider adding a limit switch to the Z axis that could be positioned to limit travel towards the spindle and prevent crashing. And how about some movable hard stops just in case????

Opinions please....

[HoboCrow]

Ron, that's Beautiful!

Really! Looking very clean. You'll be Mach3 turning in no time at all.

btw, hiding the stepper motor in between the bed legs is pretty clever Buddy ...

keep at it,

Bill S

[ronncat]

Today was the day!!! I fabricated a bottom chip guard for the screw enclosure. Put a little bend in the rearmost portion. Wala... done!!

So I got out the blasting cabinet and went crazy. I originally intended to polish a few parts, but it's much more fun to just blast away. Anyhow here are the parts after glass beading (and a little polish on one). Note there are only 6 main parts that required milling. The rest could have been cut out of sheet.



Started by assembling the saddle and apron extensions. Note the box formed by the apron and the bolttom panel. This area will be nearly impervious to chips and moisture. I think that it will make a great place to mount my Z axis home switch. I'm considering mounting the X axis switch under the cross slide adjacent to the ballscrew perhaps. This way, they will not be exposed to anything.



Finshed putting everything back together. Here are some views of the finished conversion.



And then the obligatory bling shot



The final two pics show the ballscrew covers in place. Note one of them is SS, the other blue steel. Oh well...at least I got a good deal on one of them.




Now I turn my attention to the electronics side. Need to design the Hall Effect home switches and mounts. I will probably more or less duplicate the controller box that I built for my mill. Things are starting to show up here, so I can start building soon. Fedex came twice today and UPS once. Another couple of days and everything should be here!!

Bill, Thanks for the props on the Z axis motor disappearing act. I can't take credit for that though. Someone else did it and I happened across the picture on the net. Still contemplating what type of spindle sensor to use...I'll let you know.

Thanks everyone for looking and please feel free to comment and give me your suggestions on how I can improve my design

[cornbinder23]

I hate you!!!
just kidding looks AWESOME!!! working on getting the things together for my conversion now and picked up a set of those spring covers on the "bay" last week, again that is a fantastic build Ron good on ya

JTCUSTOMS

[blades]

Wow, and I thought my 7x10 conversion was clean.
VERY nice job roncat! Very professional level conversion, worthy of fetching top dollar as a kit.

Did you mention in your thread where you sourced the leadscrew clockspring type cover? I was wanting to do something like that on my 7x10.

[ronncat]

Guys,

Thank you so much for your kind words

Remember...a little over a year ago, I was pretty much a total metalworking newbie. Almost everything I know today has been gathered from this site. I have no plans to produce a kit or plans for this.. Too many other things going on in life. I am more than happy to help out anyone who does have aspirations to do so, or even to do a one off of my design. Remember what they say... Imitation is the sincerest form of Flattery...

By the way Blades, One of the ballscrew covers was an ebay find. The proper size is really hard to find. I checked for a couple of months for a second one. I found the blue steel one at McMaster Carr. It was roughly a third of the cost of what the manufacturer quoted for a single cover. Good luck!!

[blades]

Remember...a little over a year ago, I was pretty much a total metalworking newbie.

You've certainly done very well for yourself. I've worked with machinists that had years of experience that couldn't build anything with that level of craftsmanship.

BTW, what's that screw cover called? I used several different search terms on McMaster, but didn't come up with anything. Thanks in advance!

[cornbinder23]

I believe they are called conical spring steel bellows or telescopic spring steel bellows, I found a couple on ebay for a decent price but are pretty large for my application but I am going to try and use them anyway they will just look like the one part that doesnt belong haha!!

JTCUSTOMS

[ronncat]

Blades,
Try page 3748. They are there under telescoping tapered metal covers. They are made by Centry Covers, but McMaster Carr doesn't tell you that.

[blades]

Thanks guys! I'm usually pretty good at finding stuff like that, but I was lazy last night, opting to ask instead of look.