Ramp entry (helix) too steep

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cahlfors
Posts: 61
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Ramp entry (helix) too steep

Postby cahlfors » Thu May 17, 2018 2:22 pm

The ramp entry dressup is a fantastic feature, but it looks like it dives into the material too steeply:
Markering_019.png
Markering_019.png (25.33 KiB) Viewed 426 times
This is an oval, but circles are the same. The first level is reached in just 1/2 lap (counting from material contact), the others in a full lap.
Do you agree this is an imperfection?

Cheers,
/Chris (Sweden)

OS: Linux Mint 18 Sarah
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13522 (Git)
Build type: None
Branch: releases/FreeCAD-0-17
Hash: 3bb5ff4e70c0c526f2d9dd69b1004155b2f527f2
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: Swedish/Sweden (sv_SE)
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chrisb
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Re: Ramp entry (helix) too steep

Postby chrisb » Thu May 17, 2018 3:46 pm

I can confirm this. If you are interested in a workaround you can of course change the start depth.
cahlfors
Posts: 61
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Ramp entry (helix) too steep

Postby cahlfors » Thu May 17, 2018 3:58 pm

Thanks ChrisB!
Is this where to report it?
https://www.freecadweb.org/tracker/view ... g_page.php
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chrisb
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Re: Ramp entry (helix) too steep

Postby chrisb » Thu May 17, 2018 4:01 pm

cahlfors wrote:
Thu May 17, 2018 3:58 pm
Is this where to report it?
https://www.freecadweb.org/tracker/view ... g_page.php
Yes, but we usually wait until some of the experts have looked at it.
cahlfors
Posts: 61
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Ramp entry (helix) too steep

Postby cahlfors » Thu May 17, 2018 4:08 pm

I thought you were one of them, haha :D
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chrisb
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Re: Ramp entry (helix) too steep

Postby chrisb » Thu May 17, 2018 8:22 pm

cahlfors wrote:
Thu May 17, 2018 4:08 pm
I thought you were one of them, haha :D
I try to pretend, haha :lol:
herbk
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Re: Ramp entry (helix) too steep

Postby herbk » Fri May 18, 2018 6:21 am

Hi,
there must be a thread, about a half (ore more) year old, where sliptonic explaned the behavior. If i remember right, it's like that:

The move of a Ramp Entry is always "the selected shape for the ramp" from one Z level to the next Z level. So the first ramp is from "Safe Height" to the first cutting level.
On straight ramps the ramp gets a given angle, so it works like expecded, only needs a little more time for the longer distance to go. Helicall ramping seams to ignore the angle (made just a quick check)..
May be it:s possible to change the helicall ramp to respect the given angle to, or (in my mind the better) put in a vertikal stepdown from Safe Height to the Start Depht before the first "cutting round".
Last edited by herbk on Sun May 20, 2018 7:28 am, edited 3 times in total.
Gruß Herbert
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sliptonic
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Re: Ramp entry (helix) too steep

Postby sliptonic » Fri May 18, 2018 7:48 pm

herbk wrote:
Fri May 18, 2018 6:21 am
Hi,
there must be a thread, about a half (ore more) year old, where sliptonic explaned the behavior.
I don't think it was me. I didn't write this dressup.
roivai wrote: ping
cahlfors
Posts: 61
Joined: Tue Jan 24, 2012 8:27 pm
Location: Sweden

Re: Ramp entry (helix) too steep

Postby cahlfors » Sat May 19, 2018 8:17 pm

herbk wrote:
Fri May 18, 2018 6:21 am
May be it:s possible to change the helicall ramp to respect the given angle to, or (in my mind the better) put in a vertikal stepdown from Save Height to the Start Depht before the first "cutting round".
Yes, please! Not much point in moving in beautiful patterns as long as the machine is cutting air. However, I do appreciate if the tool approaches the stock at a controlled speed, rather than full ahead until impact, so I have the option of hitting e-stop in case of something being badly wrong.

@herbk: I think you mean "safe height", or? Save = speichern, safe = sicher.

Cheers
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herbk
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Re: Ramp entry (helix) too steep

Postby herbk » Sun May 20, 2018 7:29 am

cahlfors wrote:
Sat May 19, 2018 8:17 pm
@herbk: I think you mean "safe height", or? Save = speichern, safe = sicher.
Of course... :oops: :oops:
Gruß Herbert