# Ellipse instead of a circle
**URL:** https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275
**Category:** Troubleshooting
**Created:** [March 25, 2019, 8:57am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275 "2019-03-25T08:57:04Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@heades](https://forums.maslowcnc.com/u/heades)
#### Post date: [March 25, 2019, 8:57am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/1 "2019-03-25T08:57:04Z")
So, i tried to do the sled
[http://maslowcommunitygarden.org/Sled-With-Center-Alignment-Jig.html](http://maslowcommunitygarden.org/Sled-With-Center-Alignment-Jig.html)
and that’s what i did ☹
what should i fix?
---
### Author:  [@Keith](https://forums.maslowcnc.com/u/Keith)
#### Post date: [March 25, 2019, 2:40pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/2 "2019-03-25T14:40:25Z")
Do a search for “Calibration” in the forums to get some info on your options if you have not yet done a calibration of your machine. It looks like a measured parameter might be off.
---
### Author:  [@ChrisB](https://forums.maslowcnc.com/u/ChrisB)
#### Post date: [March 25, 2019, 5:00pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/3 "2019-03-25T17:00:29Z")
I totally agree with Keith, do some calibrations, at this point it could be a number of different things so you may have to do a decent amount of testing. I would also say not to get discouraged. I would guess that almost everyone on these forums has had something like this that is discouraging but once you get it going it is very rewarding! Good luck!
---
### Author:  [@Keith](https://forums.maslowcnc.com/u/Keith)
#### Post date: [March 25, 2019, 5:43pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/4 "2019-03-25T17:43:14Z")
> [@ChrisB](#):
>
> I would also say not to get discouraged
> [@ChrisB](#):
>
> once you get it going it is very rewarding!
And you’ve done most of the hard work in that you have a machine that moves and cuts! Well done already!
---
### Author:  [@Gero](https://forums.maslowcnc.com/u/Gero)
#### Post date: [March 25, 2019, 6:48pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/5 "2019-03-25T18:48:32Z")
If you are up to it, there is a path that is a little longer, but can save time:
- With GC closed, locate the groudcontrol.ini in your user folder
- Open it with a text editor and compare the following entries with what you measure by hand (better 3 times measured then 1 time wrong {_Confucius_})
> [Maslow Settings]
> bedheight = 1222 | measure
> motoroffsety = 643 | measure
> bedwidth = 2444 | measure
> motorspacingx = 3501 | measure
> rotationradius = 140 | ring 140
>
> 
- Now start GC and calibrate but skip the ‘pull chain tight’ thing that measures the motor distance. For the other numbers above skip, or enter your masurements
- Close GC after you calibrated and open groudcontrol.ini again
- Compare the same numbers replace those that you think are not close enough to what you measured
- Start GC and cut
Please report back if this helped and also if it did not.
Kind regards, Gero
---
### Author:  [@ChrisB](https://forums.maslowcnc.com/u/ChrisB)
#### Post date: [March 25, 2019, 9:16pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/6 "2019-03-25T21:16:31Z")
Awesome diagram. I love it!
---
### Author:  [@Wallace\_Johnston](https://forums.maslowcnc.com/u/Wallace_Johnston)
#### Post date: [March 27, 2019, 12:21am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/7 "2019-03-27T00:21:13Z")
I have been looking for something like this Diagram and Step-by-Step Calibration process for some time to help me get my mind around the Benchmarks.
Although it is a bit more complicated than the “Five Cut Process” associated with Squaring Up the Base of a Cross Cut Sled on a Table Saw, the MASLOW Design is unbelievable in its application.
[Maslow Settings]
bedheight = 1222 | measure
motoroffsety = 643 | measure
bedwidth = 2444 | measure
motorspacingx = 3501 | measure
rotationradius = 140 | ring 140
Now: If the Least Likely to require a “Adjustment” is the rotationradius=140" - Which of the others (and in what sequence ) should be changed to cut a perfect circle?
And, BTW, what about the action/reaction to the TORQUE of the Router? How do we take that into account?
Old, Retired Guy in Vermont.
[Wallace.l.johnston@gmail.com](mailto:Wallace.l.johnston@gmail.com)
---
### Author:  [@dlang](https://forums.maslowcnc.com/u/dlang)
#### Post date: [March 27, 2019, 1:26am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/8 "2019-03-27T01:26:41Z")
> Now: If the Least Likely to require a “Adjustment” is the rotationradius=140" - Which of the others (and in what sequence ) should be changed to cut a perfect circle?
whichever one is wrong 🙂
this is only half-joking. There are lots of ways to attach things to the
machine, and variations of only a few mm between motor placement compared to
what the machine thinks they are can translate into up to 2x that much error on
the machine.
There is also work to improve the calibration and add additional correction
factors.
So look at those numbers and check to see if the result looks correct or not.
> And, BTW, what about the action/reaction to the TORQUE of the Router? How do we take that into account?
We don’t, the torque of the motor should rotate the sled, but sled rotation
should not affect it’s position. The bricks being on the bottom counter the
rotation from torque.
David Lang
---
### Author:  [@WoodCutter4](https://forums.maslowcnc.com/u/WoodCutter4)
#### Post date: [March 27, 2019, 2:25am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/9 "2019-03-27T02:25:55Z")
Welcome, @Wallace_Johnston. There is a LOT of great information in these forums.
> [@Wallace\_Johnston](#):
>
> I have been looking for something like this Diagram and Step-by-Step Calibration process for some time to help me get my mind around the Benchmarks.
The [“How To: Get Calibrated!” wiki](https://forums.maslowcnc.com/t/how-to-get-calibrated/6036/2) is excellent. I recommend going through all the wiki pages, actually. Also, dlang’s [“List of sources of error”](https://forums.maslowcnc.com/t/list-of-sources-of-error/7523), and these benchmarking related threads: [Triangular Linkage Evaulation Criteria and Measurements](https://forums.maslowcnc.com/t/triangular-linkage-evaluation-criteria-and-measurements/1407/74), [BenchmarkAccuracyTest20180716.xlsx](https://forums.maslowcnc.com/t/benchmark-test-and-score/4890) and [benchmark database](https://forums.maslowcnc.com/t/would-like-to-create-a-calibration-benchmark-database/8165), might be of interest to you.
---
### Author:  [@heades](https://forums.maslowcnc.com/u/heades)
#### Post date: [March 29, 2019, 5:03pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/10 "2019-03-29T17:03:34Z")
> [@WoodCutter4](#):
>
> The [“How To: Get Calibrated!” wiki](https://forums.maslowcnc.com/t/how-to-get-calibrated/6036/2) is excellent.
done, step by step 3 times, because I confused the top with the bottom.
has become smoother, however it is still not a circle
☹
> [@Gero](#):
>
> If you are up to it, there is a path that is a little longer, but can save time:
>
> - With GC closed, locate the groudcontrol.ini in your user folder
> - Open it with a text editor and compare the following entries with what you measure by hand (better 3 times measured then 1 time wrong { _Confucius_ })
will try this solution, but i dont understand, should i only do from the step 9 (aka wiki)? or early?
---
### Author:  [@Keith](https://forums.maslowcnc.com/u/Keith)
#### Post date: [March 29, 2019, 5:27pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/11 "2019-03-29T17:27:19Z")
> [@heades](#):
>
> however it is still not a circle
How close are you?
Do any of the numbers in the calibration look off to you? If so, you can tweak them to try to fix the circle
---
### Author:  [@heades](https://forums.maslowcnc.com/u/heades)
#### Post date: [March 29, 2019, 8:06pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/12 "2019-03-29T20:06:09Z")
> [@Keith](#):
>
> calibration look off to you
if they were, I would understand where to look 😂
---
### Author:  [@heades](https://forums.maslowcnc.com/u/heades)
#### Post date: [March 30, 2019, 12:46pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/13 "2019-03-30T12:46:31Z")
Or, maybe I do the wrong clamping?
 
---
### Author:  [@WoodCutter4](https://forums.maslowcnc.com/u/WoodCutter4)
#### Post date: [April 1, 2019, 1:46am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/14 "2019-04-01T01:46:14Z")
@heades
> [@heades](#):
>
> Or, maybe I do the wrong clamping?
I believe you are correct. Change it like the picture from the [assembly instructions](http://maslowcommunitygarden.org/Maslow-Ring-System.html?instructions=truce).
---
### Author:  [@Gero](https://forums.maslowcnc.com/u/Gero)
#### Post date: [April 1, 2019, 4:20am UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/15 "2019-04-01T04:20:42Z")
The assembly instruction needs to be updated.
> [@New lesson learned today](https://forums.maslowcnc.com/t/new-lesson-learned-today/3800):
>
> Just pulled the hollow link off the end of the chain today while calibrating my Maslow. My sled went swinging to the opposite side. No harm done, but thought I’d share the lesson not to attach to a link without a pin in it.
Use the second link. As long as you put the same link on 12 o’clock to feed out, the chain length will be correct.
---
### Author:  [@WoodCutter4](https://forums.maslowcnc.com/u/WoodCutter4)
#### Post date: [April 1, 2019, 1:42pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/16 "2019-04-01T13:42:34Z")
> [@Gero](#):
>
> As long as you put the same link on 12 o’clock to feed out, the chain length will be correct.
You are saying to put the second link on 12 o’clock, if using the second link on the ring?
The calibration instructions say to put the first link on 12 o’clock. Due to the safety issue you linked to, which plenty of others have experienced, should we suggest changing the calibration and assembly instructions to use the second link for the ring kit?
We would have to reference different instructions specific to ring and linkage. I use dlang’s metal linkage and must connect to the first link.
---
### Author:  [@Keith](https://forums.maslowcnc.com/u/Keith)
#### Post date: [April 1, 2019, 1:46pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/17 "2019-04-01T13:46:09Z")
> [@WoodCutter4](#):
>
> You are saying to put the second link on 12 o’clock, if using the second link on the ring?
Yes, that is what he is saying.
> [@WoodCutter4](#):
>
> should we suggest changing the calibration and assembly instructions to use the second link for the ring kit?
This has been suggested, but apparently not implemented yet.
> [@WoodCutter4](#):
>
> I use dlang’s metal linkage and must connect to the first link.
I believe @dlang has a solution for this, but I don’t remember where I saw it. He will likely weigh in shortly.
---
### Author:  [@WoodCutter4](https://forums.maslowcnc.com/u/WoodCutter4)
#### Post date: [April 1, 2019, 1:51pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/18 "2019-04-01T13:51:37Z")
> [@heades](#):
>
> [
> B3764169-692D-4C76-8052-B21028A6A51B.jpeg4032×3024 2.44 MB
> ](https://canada1.discourse-cdn.com/flex031/uploads/maslowcnc/original/2X/4/439ebe650935a0c590010a8b3ec945fde19ef6ee.jpeg)
@Keith
Or, could you do it like @heades has done but use the 3rd, or 4th?, link on 12 o’clock? I like how he put the pin through the chain, which will be safe and prevent the issue that @Gero linked to.
---
### Author:  [@Keith](https://forums.maslowcnc.com/u/Keith)
#### Post date: [April 1, 2019, 2:02pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/19 "2019-04-01T14:02:14Z")
You could. The important part is that you put the same link where it connects to the pulley traveler at the 12-o-clock position when you feed out the chain. The only thing I would be concerned about is whether the link ends up in the same position as when the cotter pin is put between the links. If it does, then you should be golden.
---
### Author:  [@Alric\_O\_Connor](https://forums.maslowcnc.com/u/Alric_O_Connor)
#### Post date: [April 1, 2019, 2:31pm UTC](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275/20 "2019-04-01T14:31:38Z")
I’m glad I randomly looked at this thread. I’ve got mine like the OP. I’m just finishing up the build, so no trial cuts yet. Still time to avoid one issue
[Next page](https://forums.maslowcnc.com/t/ellipse-instead-of-a-circle/9275.md?page=2)