Author Topic: Going over to the dark (CNC) side!  (Read 54804 times)

Offline kuhncw

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Re: Going over to the dark (CNC) side!
« Reply #195 on: May 04, 2020, 08:51:05 PM »
Jason,

Thank you for the explanation.  I've not tried suppressing an operation prior to posting the code.  I'm using MecSoft's Visual Mill Standard for CAM.  I'll see if I can do this in my version of Visual Mill. 

Chuck

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #196 on: June 01, 2020, 07:17:45 PM »
just a small part this time which is the exhaust pipe elbow for the Filer & Stowell, having learnt that I was not using the best cutting paths when I did the flywheel this was a good simple part to try out F360's  "steep & shallow" which gave a nice even step over all around the bend which was cut with a 3mm dia 4-flute ball nose cutter at 5000rpm and 300m/min feed. I pinched the idea of milling inside a square from Dave Otto's valve.



It was then just a case of plunging in from each end with a 6mm ball nosed cutter and then a 7mm flat to form a recess so that I could locate matching spigots on the ends of the 8mm OD pipe which was all JBwelded together.





A lick of paint was all that was required to complete this part and the whole engine.

<a href="https://www.youtube.com/watch?v=xMA_-hx1dSo" target="_blank">http://www.youtube.com/watch?v=xMA_-hx1dSo</a>

Online steamer

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Re: Going over to the dark (CNC) side!
« Reply #197 on: June 01, 2020, 07:43:42 PM »
That just got dropped into the pile of good ideas!   

 :DrinkPint:

Dave
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Damned ijjit!

Offline Johnmcc69

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Re: Going over to the dark (CNC) side!
« Reply #198 on: June 01, 2020, 10:47:54 PM »
 :ThumbsUp:
 Fantastic engine Jason! I like the slow running. Looks like you'll need to tame that govenor a bit.

 Will you be creating drawings? I would think this would be a popular design.

 Great work!

 John

 Also...nice touch running the wood grain parallel with the engine...  Cool little effect. :ThumbsUp:
« Last Edit: June 01, 2020, 10:51:09 PM by Johnmcc69 »

Offline kuhncw

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Re: Going over to the dark (CNC) side!
« Reply #199 on: June 01, 2020, 11:01:08 PM »
Very nice work, Jason.

Chuck

Offline Dave Otto

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Re: Going over to the dark (CNC) side!
« Reply #200 on: June 02, 2020, 12:58:35 AM »
Beautiful engine! I like how you have it angled on the base, it gives it a much different look.

Dave

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #201 on: June 02, 2020, 07:17:23 AM »
Thank's chaps.

Not sure about drawings but have started the build thread over in "own designs" It would be possible to do it all on manual machines as all the curved bits were drawn at a time when I would have had to do it on the rotary table so would not limit it to those with CNC

The governor drive belt is really too short, I need to get another so they can be joined together and take some of the load off the long overhanging pulley that is only on a 1/16" shaft which I think will help.

Dave, the angled engine does make a bit of a change to the usually mounting parallel to the sides and gets rid of that blank space on the inlet side of the cylinder with the added bonus that I could make the base a bit narrower as the exhaust did not stick out the side
« Last Edit: June 02, 2020, 07:20:46 AM by Jasonb »

Offline nj111

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Re: Going over to the dark (CNC) side!
« Reply #202 on: June 02, 2020, 02:13:19 PM »
Really nice result Jason.  That actually reminds me of similar work by Clen Tomlinson. (I am going back 15 or more years here). Some may remember the incredibly complex Napier Deltic engine he was making?
Here is a picture I took of how he made such items. They were in brass, machined both sides, bolted together then silver soldered, then cut off to length and finally nickel plated.  I have in mind Barry Hares used similar techniques (obviously without going to the dark side!)  to produce this sort of part on his remarkable Merlin and Eagle engines.  It seems a good option for items where it's not possible to machine the bore like you were able to.  Nick
Nick

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #203 on: June 23, 2020, 05:56:54 PM »
I thought it was about time to dust off the KX3 and make a bit more swarf. The chosen candidate was the base for my current engine project which I had made a bit more shapely than the engine it is based on but making the four sides concave rather than just rectangular and the curve from top out to the edges is a 1/4 ellipse so not easy to do with an off the shelf cutter particularly to get it to flow around the corners of the upper rectangular mounting surface.




Roughing

The usual 3D clearing using a 6mm dia cutter was showing quite a long run time in the simulator as it was basically just doing an ever decreasing rectangle so lots of movement and little cutting to start with as it just nipped off the far corners so I thought I would try one of ARC's 25mm insert cutters. I changed to a pocket clearing cut which spiralled down 1mm and then worked around the waste before spiralling down again, I generally prefer to use more of the cutters edge but with the inserts the cost of a couple of corners is not too great even if the sides don't see an equal amount of wear.

I will need to look at the helix that the tool follows as it spirals down if I use the method again and also support more of the work as it was getting a bit chattery as I got down to the 4.5mm (4mm plus 0.5 finish) thickness. I have already played around with this and got the tool to ramp down as it moves along which together with a few more tweaks cut about 40% of the run time.

Contour

I had already sawn to rough shape on the vertical bandsaw so only needed a couple of 0.5mm clean up contour passes and a final 0.25mm finish one and it was while doing these that I realised something was wrong as there was a lot more coming off the left hand side than the right Turns out that I had located the work based on the ctr position I had used when drawing it which was the middle of the rectangular top section (black sharpie marks on video) but F360 defaults to the ctr of the stock which being an asymmetric part was off to one side, luckily there was enough to play with except for a couple of the rounded corners so out with the JBWeld. Just a 6mm 3-flute from NC for this

3D "Steep and Shallow"

From the earlier Filer & Stowell flywheel I had found that I was using the wrong type of path with some input from Andrew and Barrie so opted for what F360 calls "steep and Shallow" that I tried on teh pipe bend posted previously which allows you to set the stepover or scallop for both steep and shallow surfaces which results in a more even finish, I went with 0.25mm in both cases and used a 4 flute Arno ball ended cutter. Quite happy with how that turned out as it needed almost no cleanup work prior to paint.

I also drilled the holes on the CNC, the larger than normal spotting holes are due to me not having modified the file after altering the hole spacing on the mating part so had to run the spotting path again with a slow downfeed so the 6mm spotting drill did not get pulled over by the previous overlapping holes.

Final job was to add some bosses around the corners which still need a bit more filleting but the Upol Rapid filler was living upto it's name this afternoon and almost setting before I could apply it so just gave it a blow over with etch for now.

Feeds 'n' speeds etc in video description

<a href="https://www.youtube.com/watch?v=JCuUzREEjy4" target="_blank">http://www.youtube.com/watch?v=JCuUzREEjy4</a>

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #204 on: July 16, 2020, 05:22:19 PM »
I carved a cylinder head for my current Thompson engine out of a bit of 50mm cast iron bar at the weekend, this is the finishing "Steep & Shallow" cut from Fusion after the adaptive clearing leaving 0.6mm and external contour finish cuts had been done.

6mm 4-flute R1 cutter at 5000rpm and 400mm/min feed with a 0.25mm stepover.

<a href="https://www.youtube.com/watch?v=CruYbOx9OR8" target="_blank">http://www.youtube.com/watch?v=CruYbOx9OR8</a>

From the other side



I also did a cooling fan from 0.5mm steel. 2mm HSS cutter made quick work of it.

<a href="https://www.youtube.com/watch?v=BdN2PFKBvoU" target="_blank">http://www.youtube.com/watch?v=BdN2PFKBvoU</a>



With the rest of the holes machined into the head on lathe and mill it's starting to look like an engine




Offline crueby

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Re: Going over to the dark (CNC) side!
« Reply #205 on: July 16, 2020, 05:30:10 PM »
Great parts, very interesting to see the CNC in action.   :cheers:

Offline kuhncw

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Re: Going over to the dark (CNC) side!
« Reply #206 on: July 17, 2020, 01:51:45 AM »
Very nice work.  Thanks for posting the CNC videos.

Chuck

Offline Muzzer

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Re: Going over to the dark (CNC) side!
« Reply #207 on: July 21, 2020, 12:51:08 PM »
Hi Jason - I guess your trial period of the steep and shallow "extension" has now ended? That and the multiaxis support are outside of the normal licence, so become unfeasible for hobby users who aren't made of money.

IIRC, they extended the trial period to get us hooked but I don't see it any more.

Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #208 on: July 21, 2020, 01:08:24 PM »
It took a couple of clicks but I was still able to get it, don't know how long for though.  :) Managed this at the weekend from a bit of EN3 but may have been EN8 going by the colour code although that can vary. I think the Z-axis damage that was done to the machine before I got it may still be affecting things slightly in the way of backlash as there are a few over depth areas - ring on inside of rim and outside of the hub and also where the cutter goes up over the spoke so need to look into that a bit more.








Offline Jasonb

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Re: Going over to the dark (CNC) side!
« Reply #209 on: July 24, 2020, 07:24:46 PM »
Those with an aversion to the brown stuff should look away now.

I thought I would see what a bit of Beech machined up like and as I happened to need to make a pattern for a bearing cap what better excuse to make some sawdust.

<a href="https://www.youtube.com/watch?v=F8n4mKccHaM" target="_blank">http://www.youtube.com/watch?v=F8n4mKccHaM</a>

 

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