Using a Test Bar to Check Spindle Run out

[@gbowne1]

You remember my built in pitching machine, well, it too suffered from some of these same alignment issues. Replaced the ball screw, the rails and trucks, disassembled the toolchanger and replaced the few wear items, some broken clips, sensors, etc. They did a ball bar and test bar test I got the highest accuracy linear stuff I could get.. all of it was very worn and not maintaned. The shop that had it was grimy and the ran the snot out of it.

[@AtManUnlimitedMachining]

Yeah, that sounds about right for the condition of a lot of Fadal's. Good thing is most times the iron is still ok and with some new parts and labor you can get them running like factory. My machine was really not that bad. Needed a set of X slides and now a Z screw. I hope the Z slides are ok, they check out ok.

[@gbowne1]

Yeah, it certainly wasn't pretty at all, but FadalCNC was good at helping me sort issues out along with talking to David DeCaussin. I couldve just settled for replacing some minor parts like the rails but I knew I wouldn't be satisified. Great video on this one.

[@agomez5278]

Thanks for sharing. There's a lot to account for. Lengths of tools, quality tool holding spindle runout, thermal expansion when spindle in rotation for second's, minutes and hours ect.. and strain on spindle when pushing through or cutting metal.

[@AtManUnlimitedMachining]

Yes there is, just the temperature change in the spindle can push tenths out. Liquid cooled spindles and ball screws really help. This machine is not on that level though.

[@t4sturm]

i really enjoy your videos man! Keep them coming.

[@AtManUnlimitedMachining]

Thanks!

[@agomez5278]

Great vid man! Very helpful with the whole thought process behind machine accuracy

[@AtManUnlimitedMachining]

Thank you

[@maulord4]

You are amazing. I hope see and understand all your videos very soon.

[@AtManUnlimitedMachining]

Thank you

[@GraphicManInnovations]

Great demonstration, thanks for your effort making this video

[@AtManUnlimitedMachining]

Your Welcome

[@EZ_shop]

Wow! I have taken some of those measurements myself, but had no idea how far the rabbit hole really went. Thanks for this most excellent content.

[@AtManUnlimitedMachining]

Yes, many people can get there head around the linear errors, but you also need to consider angular errors as well. Always keep in mind there are 6 degrees of freedom in 3 dimensional space. The rabbit hole gets really deep when you start combining errors from different parts to get total GDT

[@popo48048]

Thanks for your helpful videos. Kindly keep up with the good work

[@AtManUnlimitedMachining]

Thank you!

[@agomez5278]

Warming the spindle helps alot.

[@stephfong4577]

What's the perpendicularity of the end face of this bar, referencing the axis of the bar? And also, I can use M03 S1000 to rotate the spindle, while the test bar is in the spindle?

[@AtManUnlimitedMachining]

There is no spec on this bar for the end face. It is only calibrated on its OD relative to the tapper. You could spin it if you wanted to.

[@ankushrana8970]

Very nice video. Sir, can you make a video on how we can check the repeatability of the ball screw and which type of thread used in ball screw?

[@AtManUnlimitedMachining]

Check out the backlash video, Fadal used a metric and inch type screw depending on the machine .

[@prasanjitdas1028]

What is the runout required for spindle in vmc?

[@gerardopagan2340]

Great vid! Very helpful!👍

[@akfarmboy49]

good technical info thank you

[@offuttjr]

Thanks for the videos..👍

[@davidhawley1132]

Very informative. Thanks.

[@alrashid3216]

Alas Best wishes for you I want to order cnc machining centers in Lahore in Pakistan Can you guide me some about it

[@denisrobertoheuser4279]

Ok, but how do you know if the tapers are also in acceptable condition? Do you know of any method to check them?

[@AtManUnlimitedMachining]

You can put a very thin layer of dykem on a known good tool holder. Put it in the spindle and take it out, this should show you the grind and contact pattern.

[@denisrobertoheuser4279]

@@AtManUnlimitedMachining Actually I'm looking for something with which it is possible to measure them and quantify the deviation, for issuing a report. I believe I will have to develop a device for such a task. Anyway, thanks for answering, Tim.

[@AtManUnlimitedMachining]

I'm not aware of anything to measure a spindle tapper while its in the machine. You can use test indicators, ball bearings, and depth gauges to kind of get there, but it wont tell you the whole story like putting it on a high end CMM

[@denisrobertoheuser4279]

@@AtManUnlimitedMachining Sorry, Tim. I still make some mistakes in English. I meant "tool holders" instead of "tapers". It makes more sense now, right?

[@kevinrupp856]

@@AtManUnlimitedMachining Its called Air Gaging i.imgur.com/z7u0RTZ.jpg

[@snipereyes101]

Hey Tim thanks for the video. Just out of curiosity are you located in CT my friend Brian also has those tool curious if it's the same Brian

[@AtManUnlimitedMachining]

Buffalo NY Area

[@blh50000]

Great vid!

[@skirifles2076]

Thanks again for the vid!

[@firstlast7867]

Very nice, where do I get a test bar? Dennis L.

[@AtManUnlimitedMachining]

Hi Dennis, if you google your spindle type and "test bar" IE "Cat 40 Test Bar" you will get a bunch of results where you can order a bar. The price will depend on the quality and accuracy of the bar and range from the high hundreds to into a grand range. The bar I should had a calibration cert that showed total run out at 0.0001" the whole length of the bar.

[@turningpoint6643]

TAC Rockford, CNC Specialty store ect. There's lots of different suppliers around. Very good ones aren't exactly cheap though.

[@AtManUnlimitedMachining]

Correct, "cheap" and "accurate" don't go together very well. A good tool holder can get you most of the way there for lower cost in a home shop.

[@mtgirrl]

Here's one, www.ebay.com/itm/371534079834?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[@ggggtech75]

thanks again for the great info. I'm looking forward to the tool measurement video.

[@jijeshbc]

Great, Thank You.

[@vivek5038]

hi sir can u say in next video how to rectify this spindle run out problem

[@AtManUnlimitedMachining]

On the Fadal machines you need to have the spindle rebuilt and or reground.

[@bullrunhunter6489]

Should I worry about .0002 preload? I’m getting zero runout at the spindle up high but I believe the drawbar is bad because the tool holder runout changes depending which direction the holder is placed. I’m seeing significant holder runout even with quality brand names. It can be zero one way and .001 the other. The draw bar has been catching so I know it’s worn and have a replacement. I ask because if I’m taking it apart it’s not much more effort to swap bearings these are fairly simple to do and I have some here. Or should I change drawbar and continue to run it awhile? Also when I cleaned the taper and stuck my finger into the drawbar pushing all the ball bearings back out I noticed I was able to nearly eliminate tool holder runout. That’s a big difference from what I see. Guessing the retention knobs are being pulled diagonally and leaving that bad drawbar in will cause uneven wear.

[@anthonytran9377]

hi > do you have any video show how to check run out on lathe spindle? how much is a run out acceptable?

[@AtManUnlimitedMachining]

Hello Anthony, currently I'm only doing mill videos as that is all I have in my shop to film. Lathe maybe in the future but not anytime soon. As for run out, depends on the chuck. A four jaw chuck you basically compensate for any spindle run out when you dial your part in. A 3 jaw chuck is more important because there is no easy adjustment. If you have run out on a 3 jaw you can grind the jaws to bring it in. Check out Abom79 you tube, he does a lot of videos on manual lathes.

[@anthonytran9377]

I replaced the bearing in spindle on my lathe machine and then I check run out at face about .0006 , and .0006 at the stepper of the spindle . Do you know how to adjust the runout ?

[@anthonytran9377]

Thanks you

[@AtManUnlimitedMachining]

It is machine specific, some do not have any run out adjustment. Some have set screws to push on the bearing housings, some have cams, there are lots of different methods used on various machines. Just the way you tighten things down can shift the run out sometimes.

[@DeepakRaj-tj6ys]

What is run out any one explain

[@VKRenato]

Yesterday i crash my dmu 60 eVo :( . Runout 0.04 mm on 300mm from spindle head.

[@max_eley]

Not good!, what happened?

[@jandrews377]

Seems kinda pointless rebuilding a machine without one of those test bars. Measuring XYZ and spindle alignment 'upfront' appears to be the only way to not go in 'blind'. Bet it would also come in handy for adjusting the feet and tramming.

[@AtManUnlimitedMachining]

Tramming is a different measurement and does not use the bar. It is a good tool to have and "relatively" cheap.

[@minhnguyenvan1000]

thanks sir