Parameters for 6mm Sintra Plastic Board

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Joe Domino
Posts: 1
Joined: Tue Jan 15, 2019 7:04 am
Model of CNC Machine: Axyz Trident

Parameters for 6mm Sintra Plastic Board

Post by Joe Domino »

Axyz Trident - 10hp 24k rpm
Material: 6mm Black Sintra (PVC)
Available bits: https://imgur.com/a/cdU6jXt

Greetings everyone. I apologize in advance as I'm new to CNC Routing and will likely botch some of the terminology you're all familiar with. I have been gathering information from various forums as a guest, now that I'm getting more comfortable, I wanted to ask specifics.

I operate an Axyz Trident at work, during my short stay I have only been routing quarter-inch and half-inch plywood. With the half-inch plywood I got great results with a .25" 2 Flute Upcut Bit -- Seen here https://imgur.com/sRiN047 However, utilizing a bit like this on 6mm Sintra plastic board yields poor results - coupled with the fact I lack experience determining feeds and speeds.

To compensate, we utilize a Zund that is "more suited" for this material. The results are great, though the time spent is disconcerting. Here are the parameters for the Zund. https://imgur.com/3wDF2JG
--Also, here are the bits we use in rotation all yielding the same quality result. Mind you the Zund has a capability of 50kRPM. https://imgur.com/a/9uJtdNv

In essence, I want to determine the ideal parameters for routing 6mm Sintra Plastic Board on my machine. The route itself is a series of triangles that are close together seen here https://imgur.com/a/qj7os63

As a side note I would really appreciate anyones assistance that would be willing to go back and forth via Skype (live:joefdaniele), Discord(Claudius#6548), Twitch (joedomino), or a voice communication service you prefer.

Thank you all.

tomgardiner
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Model of CNC Machine: FMT Patriot 4 x8

Re: Parameters for 6mm Sintra Plastic Board

Post by tomgardiner »

I have cut 6 and 12mm Sintra with good results. I will have to go from memory because I am not at my V Carve computer.
Try 10-12k rpm, 100 ipm feed to start and pick up the pace until finish deteriorates or parts start to come loose. I used two flute 1/8" and 1/4" spiral FS Tool bits similar to Onsrud. Ramp in to avoid melting. I use an onion skin (cutting parts leaving .003" if the parts are small enough that the vacuum won't hold. Sintra cleans up with a metal working deburring to very well to remove the onion skin.

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martin54
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Joined: Fri Nov 09, 2012 2:12 pm
Model of CNC Machine: Gerber 48, Triac PC, Isel fixed gantry
Location: Kirkcaldy, Scotland

Re: Parameters for 6mm Sintra Plastic Board

Post by martin54 »

Speed & feed rates are more critical when cutting plastics, firstly I would look at a bit that is specifically designed for cutting plastics, single flute tend to give best results, the Onsrund "O" flute bits are I believe & I have read good reports on them, don't use them myself but that is because I am in the UK & use a UK Company who make similar bits.
Chip extraction is also important to prevent recutting & welding of the cut chips, if the machines chip extraction is not great (like mine) then using an airline to blow chips away from the cutting tool works well, doesn't need to be much, just enough to help remove the chips from the cutting area, also helps cool the cutting tool :lol: :lol:

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adze_cnc
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Joined: Sat Jul 27, 2013 10:08 pm
Model of CNC Machine: AXYZ 4008
Location: Vancouver, BC, Canada

Re: Parameters for 6mm Sintra Plastic Board

Post by adze_cnc »

However, utilizing a bit like this on 6mm Sintra plastic board yields poor results
Sintra itself has a poor quality edge at best of times. Hard to imagine making it worse...

Last time I cut 1/4" black Sintra with our AXYZ 4008 (5HP spindle) was with an Onsrud 63-775 (1/4" single "O" flute bit for soft plastics). Feed rate: 210 inches per minute; RPM: 18,000; single 1/4" deep pass.

Good chip extraction at the head. Vacuum hold-down. Used 3/4" long by 0.1" thick 3D tabs. Overall object size about 15" by 9". Edge was fine (i.e. appearing just like the factory edge). No re-melting (heat dissipation through spindle good). Trimmed the tabs with a flush-trim 2-flute straight router bit on a router table.

I could have done a 3/16" pass offset 0.03" then a final 1/16" cleanup pass to shear the 0.1" offset and clean the edge.

Steven
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