Bent collet? - Replacement rotary tool?

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stephenjbell
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Bent collet? - Replacement rotary tool?

Post by stephenjbell » Wed Dec 25, 2013 1:10 am

I've finally gotten my machine assembled. I was trying my first jobs today. Everything went great for a while, then things stopped lifting back up the way that they should and crashed into the table.

I'm not even entirely sure what has happened, but I do know that I broke the bit that came by itself with the machine, and that other bits have a bit of "wobble" to them now when I put them in the collet.

So, if the collet is bent, do I need a whole new spindle/rotary tool, or can I bend it back? How much are the ones that came with the Shapeoko, and where can you order them online? Does the Inventables kit have some kind of warranty/guarantee?

WillAdams
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Re: Bent collet? - Replacement rotary tool?

Post by WillAdams » Wed Dec 25, 2013 1:52 am

Possibly the bit worked loose ---

The Spindle is an inexpensive rotary tool --- you should be able to get one at your local hardware store (the Altocraft spindle shows up on eBay) --- but for not much more you can get a (much) better tool. List of options here:

http://www.shapeoko.com/wiki/index.php/Spindle_Options

I've had good luck w/ my Dremel 4000, which is easily sourced, but pricey, but Lowes had an inexpensive clone tool last time I was there.

There's been a fair bit of discussion here --- I've gotten a Harbor Freight 1/4" Trim Router and a 1/8" adapter which was quite affordable --- just need to make a dust shoe adapter, but it does work w/ the universal spindle mount w/ either strapping or 70--75mm bolts.
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

danimal
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Re: Bent collet? - Replacement rotary tool?

Post by danimal » Fri Dec 27, 2013 4:33 am

It sounds like you missed steps on the z axis during the job, or your z axis overheated on your GRBLsheild. Either is common due to the different setting in GRBL for the z axis motor. I would recommend that you check or lower your acceleration value and check the temps on your GRBLshield through an entire job. Also check your $4 and $5 values as they are limited by the Z axis control speed. Your machine may run fine for x and y at a given seek speed, but the z axis may be missing steps due to its faster relative rotation for a given travel along axis.

It is hard to tell if and how many steps the machine is missing at any given moment, but sometimes you will see a gradual drop in travel height resulting in a deeper and deeper first pass as your job progresses. Sometimes the machine is doing great and all the sudden the z axis overheats and misses an entire positive z axis command and the next thing that you know you are plunging all the way through your waste board at seek speeds. I have had both happen. Really it is about sitting right next to the machine for a long time tweaking everything watching every move until you get the kinks worked out. Even after I got mine running smooth job after job, I still stay in the same room every minute that it is operating. It has been a while since I needed the E-Stop, but I still am within reach just in case something fails. That is the one downfall of using steppers and having no positional feedback to the controller.
Shapeoko # 1458

RT0701C Spindle || dual y motor || x axis nema23 with custom carriage 1000mm length || z axis nema23 linear rail upgrade with 1/2-10 ACME

danimal
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Re: Bent collet? - Replacement rotary tool?

Post by danimal » Fri Dec 27, 2013 4:41 am

Also bending the collet back is a waste of time and will just result in the machine being very inaccurate from here on out. I would look at upgrading the spindle now and get something better. The one in the kit is honestly a cheap waste of money in my opinion. I took it off as soon as it was done making the mounts for my DW660 and use it now as a cheap disposable dremel tool. It is inaccurate, under-powered and really the weak point of the whole package. I hope that the either just take it out of the kit and knock a few bucks of the price, or put something in that is up to the task.
Shapeoko # 1458

RT0701C Spindle || dual y motor || x axis nema23 with custom carriage 1000mm length || z axis nema23 linear rail upgrade with 1/2-10 ACME

WillAdams
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Re: Bent collet? - Replacement rotary tool?

Post by WillAdams » Fri Dec 27, 2013 11:30 am

I wish that there had been more public discussion. I suspect it came down to price, quantity, availability, &c.

I have high hopes for the 1/4" trim router w/ adapter and wonder what a similar unit could be sourced at (esp. just the unit w/o accessories), and what the 1/8" adapter, or a custom-made 1/8" collet would cost to have machined in quantity (if it works out w/ the adapter, I'll see about getting set up to make and sell the adapters --- my book re-printing venture isn't requiring the hand-work I'd thought it would.).

The problem of course, is the low end tools are a crop shoot quality-wise.
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

stephenjbell
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Re: Bent collet? - Replacement rotary tool?

Post by stephenjbell » Sat Dec 28, 2013 2:24 am

Big thanks to both of you. I was missing steps on the z-axis (high-pitch whine when trying to G0 upward), so I'll try lower the seek speed to something more reasonable. I've ordered the DW660 and mounts, so I should be good to go.

I tried bending the collet back to straight on the spindle that came with the machine, but it wobbles no matter what I do. I would also be worried that it's been weakened by bending back and forth so that it was no longer safe. I may still *cautiously* use it as a hand dremel for cleaning up edges.

stephenjbell
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Re: Bent collet? - Replacement rotary tool?

Post by stephenjbell » Sat Dec 28, 2013 4:08 am

Will, in a forum thread from earlier this month (http://www.shapeoko.com/forum/viewtopic ... eek#p17566), you said that a good default value for $5 (default seek) would be 500. On the Hello World page, it's listed as 2500 (http://docs.shapeoko.com/helloworld.html - "These are the correct Grbl settings for the stock full kit machine."). Is that a typo?

WillAdams
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Re: Bent collet? - Replacement rotary tool?

Post by WillAdams » Sat Dec 28, 2013 4:57 am

Well, the 500 value is certain to work --- but the images on that page were all done by Edward. There are two different ones giving both values.

I believe the 2500 value is okay on the newer machines 'cause the gshield has a jumper on it for the micro stepping/acceleration for the Z-axis --- but I asked after this in an email a while ago, and am still waiting on a response. I guess we'll get this all worked out after the holidays.
Shapeoko 3XL #0006 w/ Carbide Compact Router w/0.125″ and ¼″ Carbide 3D precision collets

stephenjbell
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Re: Bent collet? - Replacement rotary tool?

Post by stephenjbell » Sat Dec 28, 2013 5:41 am

I've been playing with my Shapeoko 2 today, jogging it up and down at different seeking rates. Anything over 750 in an upward motion isn't working for me (high pitch whine, skipping steps?). Unless my machine has other issues, I think 2500 is unrealistic, and probably caused the problem that made me crash downward into my work piece. Shapeoko enthusiasts of the future would probably appreciate having a more definitive answer. Thanks for checking into this!

cvoinescu
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Re: Bent collet? - Replacement rotary tool?

Post by cvoinescu » Sun Dec 29, 2013 12:37 am

WillAdams wrote:I believe the 2500 value is okay on the newer machines 'cause the gshield has a jumper on it for the micro stepping/acceleration for the Z-axis
The jumper sets microstepping, but has no effect on acceleration. It is there to overcome a limitation of GRBL, which requires the Z axis to have a moderate number of steps-per-mm, or the X and Y axes are slowed down, even when not moving the Z axis. It is unrelated to the more important limitation of GRBL pre-0.9, which is that all three axes share the same acceleration and traverse speed. The jumper does not help with that.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

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