How much runout should I expect?

kkeller
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Joined: Mon Aug 27, 2012 4:57 pm

How much runout should I expect?

Post by kkeller » Wed Dec 05, 2012 2:00 am

I have a ShapeOko batch #4 and am starting to experiment with PCB milling. The no-name rotary tool that came with the full kit seems to have a fair amount of runout (wobble). I am curious on how much I should be seeing vs having a bad unit.

I used a Carbide Engraving Bit - 45 Degree 0.1mm Diameter and slowly moved it down until it touched the PCB. The resulting circle was made due to runout of the rotary tool( I think). Attached is a picture of the circle that was suppose to be a single hole. :)

Comments please?

- Ken -
Attachments
Image004.jpg
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Aaron Seltzer
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Joined: Tue Apr 10, 2012 4:33 am

Re: How much runout should I expect?

Post by Aaron Seltzer » Wed Dec 05, 2012 4:10 am

Was the bit straight, not bent? In the collet firmly?

Can you see it wobble?

Try rolling the bit on a flat surface to see if it is bent...

I had a lot of play in the X-Z coupling, which caused the whole tool to wander when pushing along Y. Fixed by tightening eccentric nut, but since this was a pure plunge that should not be a problem.

I provided my own tool, but that does seem bad. Proxxon has low runout, but mine died after long runs with heavy load. Now using the Dewalt 660, but have not measured its runout, but would be much better than this.

Sorry, no experience with the low end dremels.

cvoinescu
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Re: How much runout should I expect?

Post by cvoinescu » Wed Dec 05, 2012 3:24 pm

That is unusable. If it's the tool that came with the kit, and the bit is straight and seated correctly, then the tool is defective. One person said that the cheap tool did not clamp correctly if the bit was inserted all the way in -- they had to hold the bit out 2-3mm from the bottom and then tighten it. I haven't seen the tool, so I can't vouch for that, but thought it was worth mentioning.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

kkeller
Posts: 14
Joined: Mon Aug 27, 2012 4:57 pm

Re: How much runout should I expect?

Post by kkeller » Wed Dec 05, 2012 4:02 pm

Thanks for the replies...

I checked the tool and even used a different one thinking it was bent. I purchased 5 of them on Amazon and all seemed straight. I checked by rolling them on a granite surface to see if they wobbled. I also tried several other tools including the one that comes with the ShapeOko kit and all produce similar results (wider then expected cuts).

If I look closely (using a magnifying glass - I am retired ;) ), I can see a small wobble when the rotary device is running. It is especially noticeable with the Engraving Bit due to it's sharp point.

I've played a little with the collet and seating of the tool in it. I will play a little more after seeing that this is a little unusual amount of runout and your comment about tools seating.

Thanks again... I was thinking it was an unusual amount of runout but being the newbie, I thought I'd better ask.

- Ken -

kkeller
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Re: How much runout should I expect?

Post by kkeller » Fri Dec 07, 2012 2:39 am

Update: I dug out an old (30 yr old) craftsman rotary tool and used the same set up and Engraving Bit. No runout... perfect cuts...

Emailing support to see if they can replace the original tool.

- Ken -

edwardrford
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Re: How much runout should I expect?

Post by edwardrford » Fri Dec 07, 2012 8:21 am

Hi Ken,

Just an FYI: Support forwarded your email to me as well. We'll be sure to get you out a new spindle tomorrow.

-Edward
Shapeoko 1 #0 - a couple of upgrades.
Shapeoko 2 #0 - a couple of upgrades.
Shapeoko 3 #2 - Stock

PsyKo
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Location: France

Re: How much runout should I expect?

Post by PsyKo » Fri Dec 07, 2012 9:52 am

This kind of rotary tool are known to have runout but this one is effectively pretty important.
For instance, I used a 2mm to drill a hole in some Delrin with the no name rotary tool, and I ended up (from memory) at something around 2.05 or 2.08 mm.
I'll switch the tool somewhere around Christmas for a Kress 800.

It also depends on the length of your tool. But I'm assuming that a 0.1mm Engraving bit is not that long.
Shapeoko #736
Kress 800, Z Axis upgrade, dual Y, 600mm X&Y rails, metal spacers and V Wheels, home switches, 4th axis
Goko - Free CNC Control Software - http://www.shapeoko.com/forum/viewtopic ... 380#p44380

kkeller
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Re: How much runout should I expect?

Post by kkeller » Fri Dec 07, 2012 3:37 pm

Update #2: Sent an email to Inventables and got a very prompt replay saying they will send a replacement.
As others have mentioned in this forum many times... Inventables (and Edward) has great customer service!

PsyKo: the tool is not very long - about 25mm total length.

Edward: Thanks again for your constant watchful eye...

kkeller
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Joined: Mon Aug 27, 2012 4:57 pm

Re: How much runout should I expect?

Post by kkeller » Thu Dec 13, 2012 3:26 pm

Update #3: Received the new rotary tool from Inventables' Customer Service.

Tried the new tool and the runout is _much_ better. The runout on this rotary tool is about the same as my 30 yr old craftsman rotary tool I was using as a comparison.

Thanks again to Phil in Customer Service and Edward for assistance.

- Ken -

edwardrford
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Re: How much runout should I expect?

Post by edwardrford » Sat Dec 15, 2012 4:18 am

Glad everything is satisfactory. The rotary tools included with the kit are an entry level solution for the machine. They work, and IMO are the best way to start out using the machine. Once you run into a limitation, then you at least have some idea of what aspect of the spindle you're trying to improve: noise control, accuracy, power, etc.

Anyway, I'm glad you're back on track!

-Edward
Shapeoko 1 #0 - a couple of upgrades.
Shapeoko 2 #0 - a couple of upgrades.
Shapeoko 3 #2 - Stock

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