Looking for some help with Fusion 360 CAM feeds and speeds

[Anonymous]

I am fairly new to CNC milling and also fairly new to Fusion 360.  Prior to Fusion 360 I used Vectric Aspire software for my CAM and am currently using a Shopbot Alpha as my CNC machine.

In Aspire and Shopbot, all I had to set was my feed rate (in IPS) and plunge rate and my Shopbot basically ran the same speed throughout the entire job. So for example, if I had a toolpath for a 1/4 Endmill on MDF, I would set the feed to 3 IPS and plunge at 1 IPS for the toolpath in Aspire and the ShopBot stayed at that for the whole job whether ramping or cutting. My Shopbot showed Move X,Y Speed as 3 and Z Move speed at 1.

With Fusion. I am having difficulties understanding what's what and with the little job runs I've done with Fusion 360, I can't grasp how to set my speeds and during a Fusion 360 toolpath, my Shopbot is changing speeds and I can't seem to get my X,Y and Z speeds different (For example 3 IPS cut and 1 Plunge) without editing the G-Code.

I've only used the ShopBot and Aspire combination and I don't know if certain speeds should be faster (ie: Lead In, Lead Out) versus cutting speed. I am comfortable calculating correct cutting feeds and speeds but don't know how to approach the other speeds.

Since I am fairly new to all of this can anyone provide any pointers or point me in the right direction? For me ideally being able to compare how Aspire/Shopbot feeds and speeds differs from Fusion360/Shopbot that would be the best but I'm happy to read any suggestions or info. I've also included a test model I'm working with to practice my Fusion 360 CAM. https://a360.co/2C2rf9j

Thanks,

[LibertyMachine]

Responding from my smart phone while waiting on an appointment.
In the speeds and feeds column for each toolpath, there are several fields.
Fusion uses inches per tooth, which multiplied by the flute count
multiplied by the rpm of the spindle yields a feed rate of Inches Per
Minute. A feed of 3 ips would equal 180 ipm

Lead in and out can be lower or faster if you choose.

Adaptive toolpath would have feed variations, due to the "No Engagement
Feedrate" setting on the last tab of that dialog

Hope this helps!

[Anonymous]

Thanks for the reply.

I have been converting my speeds from IPS to IPM by simply multiplying by 60 which based on what you wrote should be OK.

I'm not using an adaptive toolpath yet and just using the 2d pocket and 2d contour.

[Anonymous]

After spending some time on this it seems as though the issue has to do with the Rapid movement in my CNC. It seems as thought the Shopbot post processor is not sending a G0 command for rapid movement and is instead setting the MS to .6562 so the movements are really slow and then changing the speed back for cutting.

I changed it up and set the high speed rate to the be the same as my feed rate and am hoping that is going to make a big difference.