Author Topic: Mercedes-Benz W165 Grand Prix engine in 1:3 scale  (Read 151530 times)

Offline RReid

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #330 on: April 30, 2021, 03:18:58 PM »
I've been enjoying your latest posts, but as a newer member wasn't here at the beginning. I just went back and read the first couple of pages, and really enjoyed the history and background you provided. Also your patience in using AutoCad to trace scanned images of complex parts is as impressive as your machining!
Regards,
Ron

Offline JonC

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #331 on: May 07, 2021, 08:40:36 PM »
Outstanding work Mike, replicating something like this with such dedication to the original as you have done is no mean feat.
It's not what you know, it's not who you know.
It's what you know about who you know

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #332 on: May 07, 2021, 09:01:41 PM »
Thanks Jon,  :ThumbsUp: :ThumbsUp: :ThumbsUp:

I can say the same about your Cosworth.

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline JonC

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #333 on: May 07, 2021, 10:21:02 PM »
Difference being you have little to reference and are well on the way to finishing a beautiful piece of engineering.
It's not what you know, it's not who you know.
It's what you know about who you know

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #334 on: May 07, 2021, 11:09:27 PM »
Part 13  Dry Sump Cover (Oil Pan)


Some background info:

Any racing engine is at grave risk of oil starvation and loss of oil pressure, if the oil in the sump is thrown to one side or one end, away from the pick-up pipe, during sustained cornering loads or rapid acceleration or braking. Most, if not all, racing engines therefore employ a 'dry sump' lubrication arrangement. The Mercedes Benz W165 was no exception.

The lubrication oil, supplying the pressure pump,  is drawn from a large external oil tank, which ensures a constant and reliable supply of the vital oil. Separate, large capacity 'scavenger pumps', remove the 'used' lubrication oil and return it to the external oil tank via a large oil cooler. The 'used' oil is often whipped to a froth by the fast rotating engine parts, so the scavenged oil is cooled and allowed to de-aerate and settle in the external oil tank before making another journey through the engine.

 The W165 was designed to utilize the engine oil as a significant part of the overall engine cooling system. It was fitted with number of separate  'scavenger pumps' to ensure all the 'used' oil was removed as quickly as possible.
Two 'scavenge' pumps drained the front and rear sections of the dry sump (oil pan). A separate 'scavenge' pump extracted used oil from the two camboxes, another drained used oil from the camshaft drive gear train, while yet another 'scavenge' pump extracted oil from the two supercharger compressors.

I have already posted a description of how I made the the multiple pressure and scavenger pump assembly. Now is the time to make the rather elaborate dry sump cover. The original was a very impressive light alloy casting, but I will be machining the model dry sump cover from a solid billet of aluminium. It became a very involved exercise in tool path planning and machining, which occupied me for much of the winter. The CAD drawing and tool path generation could be done in the warmth of my office and the machining was done in the outside workshop whenever conditions allowed. I find I am becoming less tolerant of cold working conditions as I get older.

I prepared for the machining, by carefully clamping a large billet of 6082 (HE30 TF) on the mill bed, the block's size was very close to the limits of travel of my Emco mill, so careful positioning was essential. I bolted two additional location plates to the bed to allow the blocks to be removed and requisitioned accurately between some of the machining operations.




Here is one of the two 200mm x 100mm aluminium blocks about to meet it's fate.

"Can you see what it's going to be yet, Ralph?"



More to follow in the next few days

Mike
« Last Edit: May 08, 2021, 12:09:30 PM by Vixen »
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Jasonb

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #335 on: May 08, 2021, 07:11:33 AM »

"Can you see what it's going to be yet, Ralph?"


It's going to be a big pile of swarf and a little bit of metal left.  ;)

Would be interesting to know what the before and after weights are.

Offline fumopuc

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #336 on: May 08, 2021, 08:37:38 AM »
Hi Mike,
I am always surprised that our metal dealers do know exactly what we expect inside of a just bought piece of metal and they have hidden it inside already.  :LittleDevil:
I will following along with interest.
Kind Regards
Achim

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #337 on: May 08, 2021, 10:35:11 AM »

"Can you see what it's going to be yet, Ralph?"


It's going to be a big pile of swarf and a little bit of metal left.  ;)

Would be interesting to know what the before and after weights are.

Well... the block started off at 1.37Kg (that a little over 3 lb) so there is plenty of potential for a big pile of swarf. You will have to wait for the finished weight.  :LittleDevil:

Achim, I did not go for the option where the dealer knows whats hidden inside. Instead I went for the cheaper "Kinder Surprise" option and will need to peel all the metal away to find out whats inside. Sometimes I am lucky and a nice engine part is hidden inside. Sometimes, there is only a useless lump of misshapen metal.

You pays yer money and takes yer chance.   :lolb: :lolb:

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #338 on: May 08, 2021, 07:09:36 PM »
The Dry Sump continued.

The inside of the dry sump cover was hollowed out in a series of layers. The depth of each layer being determined by the internal features. The bottom of the M165 dry sump cover is divided up into two deep sections. One at the front is for the forward scavenge pump pick up, while and a deeper one to the rear which also houses the multiple oil pressure and scavenge pump unit and the rear scavenge pump pick up.

I tried a new CAM program called Estlcam to create the toolpaths from my CAD drawings. Estlcam offeres an option for Trochoidal and Peel milling in addition to the normal rectangular and raster pocketing.

Peel milling is an approach that uses high feed rates, low radial depth of cut and high axial depth of cut. It relies heavily on the principle of chip thinning, using a tool path that maximizes tool wear along the entire flute length. The resulting tool path is a series of overlapping circular and arc movements with a constant width of cut. I used 10% tool diameter to define the width of cut. Trochoidal and Peel milling overcome the feed rate problems associated with rectangular pocketing where the tool engagement suddenly increases to 180 degrees of engagement in the corners of a pocket.

The inside of the dry sump cover was roughed out in a series of steps using the peel milling method. The mill table moved more rapidly than I have used before and the swarf came away as a shower if fine needles rather than chips. The constant width of cut meant the feed rate could be maintained at a constant higher speed, the metal removable rate was therefore a lot higher,








Here you can see the completed roughing out cuts which were made with a standard end mill. The next operation is to use a ball bill to radius the corners of the pockets and add the 3D slopes.




Here are the tool paths I created to do the 3D contouring using a 6mm ball mill. The depth intervals were typically 0.25 mm (10 thou) but you can see these were made closer in areas with a more rapid change of slope.






Here you can see the result of the 3D countouring and corner radius operations. Very little hand finishing will be required to smooth surface of the 3D contoured areas.






This final image shows the dry sump, after the internal machining operations, alongside the engines crankcase




Stay tuned, there is more to follow in the next few days

Mike

« Last Edit: May 08, 2021, 08:06:38 PM by Vixen »
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline fumopuc

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #339 on: May 08, 2021, 08:01:13 PM »
Hi Mike, I like these kind of swarf / chips very much. My wife not, specially if she detect them in the bathroom.
Good to know, that you have found with Estlcam the way now to do this kind of milling also.
I my eyes it is very useful for our not so rigid hobby machines.
Kind Regards
Achim

Offline steamer

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #340 on: May 08, 2021, 08:10:23 PM »
I can see some similar parts for the 917 engine there... Nice set ups!

Dave
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Damned ijjit!

Offline Jasonb

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #341 on: May 08, 2021, 08:40:47 PM »
Looking good so Far. I tend to use those type of cuts a lot in F360 which they call "adaptive" quite satisfying watching the rooster tail of swarf flying out

For the finishing ones they have one called Scallop which moves the tool by a given stepover no matter what the angle of the surface or you can split it into more vertical or horizontal and have vertical stepdown or horizontal stepover.

Offline Vixen

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #342 on: May 08, 2021, 09:01:06 PM »
Hello Jason,

This type of rapid machining has several names. I rather like the term 'Peel' milling as it describes the process of removing a deep but thin shave cut rather well. Yes the rooster tail of needles looks impressive but they tend to stick to your clothing more and can get transferred into the house, which is bad news.

I am sure F360 has more capabilities but I have not kept up with the computer 'arms race' so I am unable to use it or even the 'free' version.. Are all the milling options still available on the 'free' edition?

Mike.
« Last Edit: May 08, 2021, 09:39:43 PM by Vixen »
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Craig DeShong

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #343 on: May 08, 2021, 10:29:34 PM »
Sometimes I am lucky and a nice engine part is hidden inside. Sometimes, there is only a useless lump of misshapen metal.

You pays yer money and takes yer chance.   :lolb: :lolb:

Mike

Boy oh boy, have I been there before  :facepalm:
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline Jasonb

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Re: Mercedes-Benz W165 Grand Prix engine in 1:3 scale
« Reply #344 on: May 09, 2021, 07:18:32 AM »
You get almost all the milling options on the free one. "steep and shallow" is not available and is even an "extra" if you pay the yearly subs but similar results can be had with a little more work on the CAM. Rapids are probably the biggest loss but again depends on what your max is on the machine, mine is set at 1500mm/min not 10m like a pro machine can handle. As the CAM comes out with the rapids the same as the feed rate then this type of cutting is useful as you get faster rapids than if you were using a slow feed, playing with stay down distances and non engaged feed rate can also help keep overall run time down.

What sort of height and feed did you use on that, I tend to do most work with 6mm, 3-flute carbide cutters and 6mm high x 1mm stepover does not stress the machine when run at 5000rpm and a feed of 500-600mm/min. I did scare myself yesterday when I had put 1500mm/min for the ramp feed rate and was using a helical ramp to enter the work but it went alright as I had preedrilled part diameter and the iron flywheel came out OK :-[

 

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