Author Topic: Going over to the dark (CNC) side!  (Read 12760 times)

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #150 on: December 28, 2019, 01:13:23 PM »
I draw in Alibre but do the CAM with Fusion 360, it defaults to climb milling but you also have the "both ways" or conventional option, you can also set a different feed and DOC for the conventional as the cutters seem happier with climb cuts so can take a bit more off in that direction. Andrew Johnston pointed me that way early on and I use it all the time for the main adaptive and a lot of the time for everything else as it saves a lot of time.

Online steamer

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Re: Going over to the dark (CNC) side!
« Reply #151 on: December 28, 2019, 04:23:02 PM »
I draw in Alibre but do the CAM with Fusion 360, it defaults to climb milling but you also have the "both ways" or conventional option, you can also set a different feed and DOC for the conventional as the cutters seem happier with climb cuts so can take a bit more off in that direction. Andrew Johnston pointed me that way early on and I use it all the time for the main adaptive and a lot of the time for everything else as it saves a lot of time.

You'll get better finishes as well with a climb cut

Dave
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Offline gerritv

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Re: Going over to the dark (CNC) side!
« Reply #152 on: December 28, 2019, 06:49:05 PM »
Jasonb, are you using the Fusion360 Hobby/non-commercial license with 2.5 axis only or the next level up (which now costs money?)

I am heading to CNC land again myself, getting some stuff ready.

Gerrit
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Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #153 on: December 28, 2019, 07:18:07 PM »
I just have the free one but can use the 3D CAM functions.

Offline Muzzer

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Re: Going over to the dark (CNC) side!
« Reply #154 on: December 29, 2019, 12:20:37 PM »
Look again, gerritv - the hobby users get the FULL simultaneous multi axis version (aka Ultimate) with NO limitations. Costs you nothing unless you are running a commercially viable company. The conspiracy theorists like to infer that Autodesk will start to charge once everyone's hooked but instead they seem to be intending to continue on this model, with paid-for "extensions" for some of the newer, more professional features (part scanning, generative design etc), and stuff like technical support limited to the subscription versions (that seems fair enough), as explained in this link:
https://www.autodesk.com/campaigns/fusion-360-for-hobbyists

For amateur use, the excellent support forums and myriad Youtube tutors are more than enough for most learning styles.

What's really handy is the ability to switch quickly back and forth between CAD and CAM within the same environment so you can modify the model when you come to creating the toolpaths - in practice this is what you need to do in any CAM application to get the best result and (ahem) beats creating the model in one program and the toolpaths in another ;-)

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #155 on: December 29, 2019, 01:15:00 PM »
Thanks for the confirmation Murray.

As you say being able to pop back to CAM to make alterations is handy, I have still done it with my imported parts but not as easy and also if you alter the part in a different CAD program you have to import again and start the CAM from scratch. There is still far more than I'm ever likely to need in the free version.

Offline gerritv

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Re: Going over to the dark (CNC) side!
« Reply #156 on: December 29, 2019, 03:47:15 PM »
Thank you Muzzer. I now went back and looked again, you are correct. At some point early in the switch over to 3 types of licensing I was reading too many posts elsewhere :-) Software development is not trivial or inexpensive so they at some point need to monetize the product to stay in business.

Gerrit
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Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #157 on: January 12, 2020, 04:25:07 PM »
Having spent quite a while on Frday evening and even more on Saturday flicking the RMC type A flywheel round I came to the conclusion that it is not going to work on propane instead of the now unobtainable MAPP gas I drew out a new head for it last night so it can be built as a 4-stroke, did the CAM this morning and then after lunch got the Sieg KX3 to spit out the new head in just over an hour. Still needs some holes here and there but will do those on the lathe and manual mill and then give it a lick with the needle files to get rid of the contour lines..




Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #158 on: January 26, 2020, 04:28:35 PM »
I have machined a few more bits for the 4-stroke conversion of the RMC engine. Rocker arm to operate the exhaust valve and a post to mount it on that is fixed to the head. I will bond this on with JBWeld and also fill the CSK screw holes and add some fillets to the internal corners so that the post looks like it was cast as one with the head. Both done on the KX3 and needing two setups each so that both sides could be machined.






And made a start on the epicyclic gearbox by cutting the eccentric on the CNC which did the profile with ease and also made light work of the doglegged end that lofts from a rectangle at the eccentric to a circle where the rod enters with just a light touch of a needle file required to blend the remaining too step overs. That is a 10-20-40 block not a 1-2-3 one!




Offline scc

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Re: Going over to the dark (CNC) side!
« Reply #159 on: January 26, 2020, 09:48:11 PM »
I'm enjoying progress with this one :popcorn: :popcorn:    but cnc, etc is not for me :old:    Regards       Terry

Offline zeeprogrammer

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Re: Going over to the dark (CNC) side!
« Reply #160 on: January 26, 2020, 10:37:14 PM »
Love the finishes.

... of the now unobtainable MAPP gas ...

Perhaps I missed the posts regarding this. Why do you say it is unobtainable? Is it a UK thing? Or are you referring to the original MAPP gas? I understand it's production was stopped (or reduced) some years ago and products called MAPP are substitutes with a different composition.

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Offline crueby

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Re: Going over to the dark (CNC) side!
« Reply #161 on: January 26, 2020, 10:42:26 PM »
Love the finishes.

... of the now unobtainable MAPP gas ...

Perhaps I missed the posts regarding this. Why do you say it is unobtainable? Is it a UK thing? Or are you referring to the original MAPP gas? I understand it's production was stopped (or reduced) some years ago and products called MAPP are substitutes with a different composition.
The original stopped production in the US at the only plant that made it in 2008, the current stuff labelled as MAPP is not the same chemically, I've noticed that in my torch made for the original stuff it does not burn anywhere near as hot, harder to start it burning correctly, and goes out once in a while. Still works fairly well for small jobs.

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #162 on: January 27, 2020, 07:02:52 AM »
Zee, as Chris says the original is no longer made, it had quite a lot of hydrogen in it which was what these engines like in fact the ones at places like Coolsprings run on about 85% Hydrogen with the remainder made up of propane and a few other gasses as it is the nearest to the old illuminating (town) gas.


Terry, I felt the same and even turned down an earlier offer of a machine for free but now that I have this one it certainly has it's uses though I'm not going to be going over to a full CNC only workshop anytime soon. If I had also had to learn CAD to draw the parts and also learn to write the G-code then that would have been a big put off but I could do the CAD anyway and Fusion360 does all the CAM so I don't need to write actual G-code.
« Last Edit: January 27, 2020, 07:06:23 AM by Jasonb »

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #163 on: February 15, 2020, 10:24:44 AM »
Who Needs MAPP gas when you can design your own cylinder head and other bits to make the engine run as a 4-stroke, looks like all the parts work :pinkelephant:

In fact they almost work too well as I am making so much compression it is hard to flick the engine over to get it started there is so much bounce :)