M900 exhaust Flange

[pooh]

Hi Folks
I don’t suppose anybody has an original exhaust flange they could take the measurements from so I can have two machined out of stainless. The ones I have are ally and have deformed so can’t get accurate measurements off them.

Thanks

Pooh

[Albie]

Hi Folks
I don’t suppose anybody has an original exhaust flange they could take the measurements from so I can have two machined out of stainless. The ones I have are ally and have deformed so can’t get accurate measurements off them.

Thanks

Pooh

Still available new from moto Rapido. Not expensive too.

[slob]

can't you just measure the pipe diameter and the spacing of the studs on the head?

[Mr Gazza]

I'll be having the exhaust off my M900ie very soon for a little buff up. I'll try and slip a flange off tomorrow and send you some dims.

[Nasher]

This is what I had made in Aluminium for my Carbie 900.
Unfortunately I can't find the CAD file at the moment.

https://i.postimg.cc/7ZwZWVFw/Ex-Flange-2.png (https://postimg.cc/zV2NLnDc)

https://i.postimg.cc/rwjwX4TW/Ex-Flange.png (https://postimg.cc/DSWT188y)

Nasher.

[slob]

Do you have a note of the stud spacing? assume studs are M8 (9mm loose clearance)?

DOH! just the spacing, spotted R4.5

[Nasher]

Slob

I've only just noticed that the crucial dimension of the stud centres is missing.
But they are M8.

I had them made from the CAD file and my CNC guy sent me the above back when he had a couple of questions.

I'll have a look and see what I can find.

Nasher.

[Nasher]

Sorry, all the CAD files for this part are on my CAD software equipped desktop machine at work, and I'm working from home on a Laptop at the moment.

I should of course also add that the ones I had made work with the Separate half Collets.

Nasher.

[slob]

I knocked up a CAD model, just got to set the stud spacing and export .STL unless you get back to work first ;-)

I just measured the spacing on an M1100 engine model and I think it'll be 62mm

[Nasher]

Unfortunately, and I do mean this, it's going to be a while before I'm in work again.
I've dropped in briefly @ once per month since last March.

I work for a large American Aerospace company that has effectively banned us from site if we can work from home.
They are too scared that if they tell us to go in to work we'll sue them if we get ill.

Nasher.

[slob]

Look on the bright side mate, it's nice to have a secure job at the moment, an understanding (or worried about litigation) employer can only help ;-)

If someone can confirm 62mm I can upload the file...
(I've assumed/eyeballed the central slot size, which I'm guessing isn't a critical dimension)

I just happened to have a CAD package open when I saw your post

[Nasher]

This other view I've found appears to show the 9mm Stud holes just touching the 53mm Dia recess for the Split collets.

So the 53mm + 2x4.5mm to the stud centres would suggest 62mm stud centres.

https://i.postimg.cc/43Z5Fr5w/Capture222.jpg (https://postimages.org/)

Nasher.

[slob]

based on those measurements here's a .STEP file of my CAD model (without warranty of course)

http://www.thelasturl.net/ukmoc/M900_Exhaust_Flange.step

I set the central rebate at 6mm wide as that looked like your machinist's drawings, based on the 2mm depth.

http://www.thelasturl.net/ukmoc/M900_Exhaust_Flange.png

[Nasher]

Cheers Slob

I Did offer at the time to have a batch made but nobody was interested.

I might get my CNC guy to quote them again.

Nasher.

[slob]

5 pairs (Al6082) where about twice the price of a single pair when I uploaded to a CNC service as a test (similar economy of scale to the clip-on spacer I modelled the other week)
Mind you, I only have a non-commercial license for the CAD ... but I'll happily make 3D models of parts club members want for free ;-)

[crust]

Don't forget, the rear cylinder one has a cut out to clear the head.



https://i.ebayimg.com/images/g/Ep0AAOxy4dNS4ro~/s-l1600.jpg

[slob]

Don't forget, the rear cylinder one has a cut out to clear the head.



https://i.ebayimg.com/images/g/Ep0AAOxy4dNS4ro~/s-l1600.jpg

Good spot Mr. Crust, do you have a measurement? I can do a second version... of course that'll push the machining cost up for anyone who gets them made.

[Nasher]

Don't forget, the rear cylinder one has a cut out to clear the head.



https://i.ebayimg.com/images/g/Ep0AAOxy4dNS4ro~/s-l1600.jpg

I didn't find that on my Carbie 900, the one I posted the image of fitted both cylinders.

https://i.postimg.cc/0jyxdkrS/Horiz-Fitted.jpg (https://postimg.cc/ftp6MhcW)

https://i.postimg.cc/G2Qdy83r/Vert-fitted.jpg (https://postimages.org/)

Nasher.

[Mr Gazza]

Both my clamps have that chamfer, but it does not appear to have any purpose.. It's certainly not for clearance of anything on my M900ie model.
Maybe just to make the front one a bit more aerodynamic?

[Darkness]

Stein Dinse list the flange part number as fitting:


Ducati
Ducati 750 Paso `84-`92 , BJ 1984 - 1992
Ducati 750 Sport
Ducati 750 SS `91
Ducati 750 SS `92
Ducati 750 SS i.e.
Ducati 750 F1/Laguna Seca
Ducati 900 SS `90
Ducati 900 SS `92
Ducati 900 SS F.E. `98
Ducati 900 SS inj. `99
Ducati 900 SS/SL `94-`97
Ducati 906 Paso `88
Ducati 907 I.E. `92
Ducati Monster 600 `94
Ducati Monster 600 `98
Ducati Monster 600 `98 Dark
Ducati Monster 600 `00
Ducati Monster 750 `00
Ducati Monster 900 `93
Ducati Monster 900 `94
Ducati Monster 900 `98
Ducati Monster 900 i.e. `00
Ducati ST 2 `97

Some of which have the rear cylinder head “reversed” with the exhaust port at the front. That must make the exhaust radius pretty tight from the head to require the chamfer.

[Mr Gazza]

I think the only one with a reversed head on that list is the 750 F1. All the exhausts I looked at on google images seem to have a good straight length coming out of the port, so I don't think that's the reason for the chamfer.
The clamps on my 750 seem to be a slightly different design. (no idea if they would interchange with 900?) They have no chamfer on either clamp and don't interfere with anything. However, on the smaller engine the clamp would get very close to the crankcase when at the end of the studs and be tight to get off to release the collets. I can only assume that it would be tighter still on the 600 engine and a chamfer might make all the difference, but I have my doubts as to 900 and 600 clamps being the same animal?

I think this chamfer might be a Red Herring?

[slob]

If someone can measure and let me know how much needs milling off that side to match the stock part I'll upload a file so both with and without are available.

[utopia]

I fitted a Sil-Moto big bore exhaust from an M900 to my yr2000 M750 a while back, which came with its own flanges.
The Sil-Moto flanges fitted my 750 motor (although the headers needed modifying) and so I was wondering if the std flanges were the same across the range. From the list that Darkness provided it would seem that this is commonly the case (though I suppose I would still hesitate to say for certain that it is always the case).
So I have (and can therefore measure) a pair of original flanges from my 750 amongst my stock of bits and pieces .. and these are very probably the same as 900 ones.

Using a decent pair of Mitutoyo dial calipers I have taken the following measurements to determine the stud hole spacing :-
Max distance across stud holes (ie between outside edges) = 2.790" = 70.866mm (ave of 4 readings).
Dia of stud holes = 0.351" = 8.951mm (ave of 8 readings)
Therefore, distance between stud hole centrelines = 61.951mm
I include all the above extraneous detail merely to indicate the accuracy of my measurements.
To all intents and purposes, the hole spacing is 62mm.
This tallies with Rob's measurement from the M1100.

I cross checked the dims from Nashers drawings and found that :-
Basic bore is confirmed at 48mm dia.
Basic bore increases to 54mm where the half rings fit (Nasher's drg states R26.5, ie 53mm)
Depth of this feature is confirmed at 2mm.
Max dia is 63mm (Nasher's drg states R33, ie 66mm dia) .. however the flange's outer profile is a little more "shaped" than Nasher's drg and the outer width in the area of the stud holes is approx 84mm. I can't confirm the 11mm radius in this area but its probably just down to a cosmetic blending.
Max thickness is confirmed at 16mm (I actually measured 15.875mm) BUT this is reduced around the stud holes to 14.75mm.

And, I imagine the flats on the flanges are to give clearance when used on the shorter stroke 750 and 600 motors.
These are tricky both to measure and to describe.
Using my engineer's angle gauge I reckon they are at an angle of 20deg to the axis of the exhaust port, ie 70deg to the flat face of the exhaust flanges
The "depth" of these flats leaves a land of minimum width 2mm (approx, by ruler) on the outside face of the flange and a land of min width approx 6mm on the outer dia of the flange.
There is also a small chamfer on the outer edge of the main bore. This is approx 2mm wide.

Obviously I have these flanges (and the associated half rings) to hand, so let me know if you need any other dimensions measuring.

Hope that all makes sense without pictures.

[slob]

Thorough as always Jeff! although I'm not 100% without a picture.
Since Nasher's collars look great and clearly fit, I've stuck with his measurements.
For the one with a flat, I've reduced it to 3mm where indicated but left it 'square' at the side rather than at 70deg.

http://www.thelasturl.net/img/M900_Exhaust_Flange_Flat.png

Do you think it needs more material taking off?

A 'nearest mm' measurement with a ruler, to the flat from the other side would have done for me

http://www.thelasturl.net/img/measurement.png

[Mr Gazza]

'Scuse the Sugar beet in the fins, I ride in Norfolk!

It looks like this. Best I can measure is that the slope starts 6mm from the engine side of the flange and there is about 2-3mm left at the other side between the slope and the hole.
I can tell you more when I get it in my hand, if you want more?
In my opinion it's not worth bothering with. Nasher's non-chamfered one looks fine.

https://i.ibb.co/S3m9qHt/exhaust-flange.jpg (https://ibb.co/FDYjGc5)

[Nasher]

however the flange's outer profile is a little more "shaped" than Nasher's drg .

Well done Utopia, as Slob says, very detailed as usual.

I suppose I should admit at this late point that when I did the CAD model for mine I didn't in any way try to emulate the external shape of the original steel ones, for two reasons really.
Firstly because I wanted a nice clean shape.
Plus to simplify the profile and keep the machining costs as low as possible.

Then when I fitted them I realised that purely by chance I'd almost matched exactly the shape of the casting of the head where the exhaust attaches.

Nasher.

[pooh]

Thanks guys brilliant info I can now get the flanges machined ready for the new exhaust to be built.

Pooh

[Nasher]

What I must get around to doing is my plan to attempt to find some very thick wall 54mm OD Stainless Steel tube, or bar, and machine it into split collars in my lathe to replace the horrid rusty steel originals.

Nasher.

[slob]

Aha, now I can see round the back of Crust’s picture I understand what utopia means,
I won’t upload the modified file unless someone specifically requests it.

[pooh]

Nasher, I’ll have a look in my metal store I think I’ve got some material that will do if I have I’ll make some and send you a set.

Pooh

[utopia]

Looks like we're just about there then ?
I would just emphasise a few points :-
1) The effective thickness at the studs is 14.75mm. If you make them 16mm you lose 1.25mm of stud thread. Probably of little consequence but worth noting anyway.
2) The bore of the recess where the split rings fit is 54mm. Nasher's drg states 53mm which is a tad undersize (although it seems to have worked ok).
3) The easiest way to put the chamfers on (for 600 and 750 owners) would probably be by eye on a trial and error basis, using an angle grinder. Note that too big a chamfer could weaken the flanges.

[Nasher]

Nasher, I’ll have a look in my metal store I think I’ve got some material that will do if I have I’ll make some and send you a set.

Pooh

You're a star Pooh.
Oh, that sounds like I'm being rude, calling you a prize 5h1t, but obviously I mean exactly the opposite :mand:

I have an original one in the garage and had a quick measure up last night.
The stud spacing is 62mm.
And on my one the diameter of the recess for the collets is definitely 53mm, and that's after scraping it back to sound metal.

Nasher.

[Mr Gazza]

3) The easiest way to put the chamfers on (for 600 and 750 owners) would probably be by eye on a trial and error basis, using an angle grinder. Note that too big a chamfer could weaken the flanges.

I would use a fixed disc sander or belt sander to take the chamfer off especially if it's ally, it don't grind that well. Even stainless will sand off, usually quicker and cleaner than a grinder, although those thin cutting discs are rather good in a 4" angle grinder.

[utopia]

And on my one the diameter of the recess for the collets is definitely 53mm, and that's after scraping it back to sound metal.
Nasher.

In that case I thought I'd better double check the recess on mine.
Both of them are definitely 54mm. That's measured with a dial caliper.
Curious.
I wonder whether this was increased (by Ducati) at some stage.
Just out of curiosity Nasher, does your's have the chamfer on the outside ?
I'm wondering whether early ones, ie when there were only 900s around, were different.

[Nasher]

In that case I thought I'd better double check the recess on mine.
Both of them are definitely 54mm. That's measured with a dial caliper.
Curious.
I wonder whether this was increased (by Ducati) at some stage.
Just out of curiosity Nasher, does your's have the chamfer on the outside ?
I'm wondering whether early ones, ie when there were only 900s around, were different.

No Chamfer on the one I had to hand.

I have 5 or 6 more buried in a box somewhere, so will dig them all out, measure them and check for chamfers as soon as I get a chance.

The problem is that apart from the two that came off my M900 all the rest have arrived with me in boxes of bits I've brought over the years, so I don't know for sure what they came off.

Nasher.

[Dukedesmo]

I have a different type now as my (new) exhaust is held on with springs but previously when using the original downpipes I had some old-fashioned looking finned flanges that were a nice alternative;

https://www.ducatiforum.co.uk/data/photos/l/5/5369-1424641948-121c13717f3dad0c05b71f94672dffb8.jpg

https://www.ducatiforum.co.uk/data/photos/l/11/11132-1611158554-52b75e2e703b8dcd8d3842c952be0dc2.jpg

Not sure what the chamfer to clear the head is about as these were considerably larger than the standard parts, yet fitted with no issue on both cylinders?

Obviously a little more tricky to make unless you've access to CNC equipment though...

[Darkness]

I have a different type now as my (new) exhaust is held on with springs but previously when using the original downpipes I had some old-fashioned looking finned flanges that were a nice alternative;

https://www.ducatiforum.co.uk/data/photos/l/5/5369-1424641948-121c13717f3dad0c05b71f94672dffb8.jpg

https://www.ducatiforum.co.uk/data/photos/l/11/11132-1611158554-52b75e2e703b8dcd8d3842c952be0dc2.jpg

Not sure what the chamfer to clear the head is about as these were considerably larger than the standard parts, yet fitted with no issue on both cylinders?

Obviously a little more tricky to make unless you've access to CNC equipment though...


They would go well with finned magnesium rocker covers.

https://www.ducati-kaemna.com/catalog/ducati/monster-750-900-1000/zylinderkopf-nockenwellen-cylinder-head-camshaft/magnesium-ventildeckel-2v.html

[Nasher]

I managed to dig out my Stash of standard ones of these.

I have to admit to two things:

1) My name is Nasher, and I'm an Exhaustflangeoholic.
I found 7 of them in my box of engine bits and pieces :eyepopping:

2) And I don't know how I missed this, all 7 have a small chamfer on them!!:scratch:
I obviously decided when I drew up my Ali ones that it was not needed, and the one I looked at the other night has a very very small chamfer on it.

I measured them, and all have the stud holes at 62mm centres.
The range of diameters for the recess where the collets go is between @52.8mm and @53.7mm.
Interestingly the pair in a separate bag that came off the M900 had smaller Chamfers, and recesses closer to 53mm than 54mm.
As a pair they also appear to be a slightly different outer profile and made from a different steel.

Oh, and I'm really liking the finned ones fitted by Dukedesmo.

Nasher.

[slob]

http://www.thelasturl.net/img/M900_Exhaust_Flange_Fin.png

think it might push the cost up quite a bit

[Mr Gazza]

Those finned flanges would suit my 750 project down to the ground. Can you remember where you got them Tim?
I had also thought about fitting Pantah valve inspection covers, but don't know for sure that they would fit.. Those Kaemna ones would fit the bill though when they are available again.

[slob]

Who’s got a loose valve cover they can measure up?

[Nasher]

Slob

I might have several of those too:biggrin:

I'm happy to post you one to measure up yourself, but can't get to one until the weekend.

Nasher.

[slob]

it occurs to me i have a 620 buried at the back of the garage, i just need to measure the crown and order a gasket i guess.
I can 3d print the parts in plastic to confirm fit before machining metal

[Mr Gazza]

The thread seems to have bifurcated into valve covers and exhaust rings?

Pondering the valve covers I remembered that Nick "The Clockie" had Pantah valve covers on his M750, or at least look-alike ones, maybe the Kaemna ones. He also still has an Alazzura with a Pantah engine so the possibility of some measuring exists.
It also appears that the finned exhaust rings might originate from Pantah, they look superficially simillar.

Dacs has just pointed out that there is no oil cooler mount on the Pantah, but I had intended to try and reduce the size of that and tuck it out of the way somewhere, so not a massive issue for me.

[slob]

easy enough workaround
http://www.thelasturl.net/m1000/bracket.jpg

[Dukedesmo]

Those finned flanges would suit my 750 project down to the ground. Can you remember where you got them Tim?


Yes, I've found the invoice. I got them from Ricambi-Weiss in Germany; https://www.ricambiweiss.com/en/ however I've just looked on their website and can't see them so maybe they don't do them any more?

Might be worth emailing them though? the description on the invoice is 'Krummerflansche CNC Ducati 600 750 900 Monster' cost me €25 back in 2010, unfortunately I sold them to someone on a forum after I changed my exhaust so don't have them any more.

[Mr Gazza]

Thank you Tim. :thumbsup:
I might drop them a line, although I saw some Pantah ones somewhere for about 113Euros, so they might have gone up a tad?
Germany is difficult to deal with right now, my brother lost some car parts that he ordered in December... They never made it across the border!

[slob]

http://www.thelasturl.net/img/M900_Exhaust_Flange_Fin.png

The finned version is just over double the cost of the plain one due to increased processing time on CNC although I haven't refined the model to make it as simple as possible yet.

[Darren69]

The MH900e had the finned version: Part no 57510041A

https://www.ebay.co.uk/itm/Ghiera-di-Scarico-Originale-Ducati-per-MHe-01-Cod-57510041A/262093065411?epid=1444223035&hash=item3d05f6ccc3:g:hnEAAOSwI-BWHgh9

[slob]

Then you just need to track down a Japanese sport 1000 cup bellypan and slot it for a sidestand for the full effect

http://www.motorcyclespecs.co.za/Gallery/Ducati%20MHe%20900e.jpg

[Mr Gazza]

Good call Darren.

Rob, the MHR one only has 6 fins either side, which would be simpler. Could you get the nice petal shaped fins?
What sort of ball park are we looking at for these?

[Mr Gazza]

[QUOTE=slob;582815]Then you just need to track down a Japanese sport 1000 cup bellypan and slot it for a sidestand for the full effect[QUOTE]

What a ghastly bike! So you insulate the sump and filter and put a bigger oil cooler on??

Typically I'm always beaten to my ideas. I had thought about a little finned fairing for the starter motor to empathise with the bevel's forward sump protuberance, but that one goes too far!

[slob]

Good call Darren.

Rob, the MHR one only has 6 fins either side, which would be simpler. Could you get the nice petal shaped fins?
What sort of ball park are we looking at for these?

Up to a point, more machining 'soft' radii = more time = more cost

I used a German website that spits out automatic CNC quotes, just to get a rough idea.
Finding a UK supplier would be key to making it more economical now I guess.
The copies of Luddite's ones where ~€44/pair + VAT, duty and p&p based on 5 pairs.
The finned ones were ~€90/pair + ...

I'd call MR and see if the cast OEM ones are available and how spare parts prices may have changed this year.

You've got me thinking and in between playing with a CAD model of a finned valve cover, I'm looking at home sand casting videos on youtube now...

[Darkness]

Up to a point, more machining 'soft' radii = more time = more cost

I used a German website that spits out automatic CNC quotes, just to get a rough idea.
Finding a UK supplier would be key to making it more economical now I guess.
The copies of Luddite's ones where ~€44/pair + VAT, duty and p&p based on 5 pairs.
The finned ones were ~€90/pair + ...

I'd call MR and see if the cast OEM ones are available and how spare parts prices may have changed this year.

You've got me thinking and in between playing with a CAD model of a finned valve cover, I'm looking at home sand casting videos on youtube now...

Low pressure sand-casting of magnesium alloys throws up some interesting papers.

[Mr Gazza]

Mmm? The prices for CNC are always going to be up there for one offs or small batches. The thing is it might even be a bit too "sharp" for the desired effect? The originals were cast or forged, so thinking that a square finned CNC ring could be hand fettled and then say blasted for a cast look, it does lead on to casting our own.
I have a stash of scrap ally accumulated as I was heading towards casting some bits a year or so ago. I did some sand casting at school and it's not hard at all, all you need to buy is the sand which is easily available and can be used many times, as can the metal if it doesn't go well the first time.
A box of two indexed halves is not rocket science and then all that's needed is a couple of wooden "carrots". Patterns can be anything, obviously I would go straight to MDF. One pattern will make multiple casts. It would only remain to find someone to machine the critical areas, most critical being a nice flat gasket face for the valve cover. The exhaust rings have only got to push on the collets, so not a precision part.

Thinking as I type, the easiest way to make a valve cover pattern would be to stick some MDF fins on an old one... A bit of filler here and there, an hours work. :mand:

[slob]

I was thinking 3D printing for the plugs.

I liked myfordboy’s stuff on youtube (https://youtube.com/playlist?list=PLD2A7F5FD2D3C3088)

lost PLA is a clever technique, a natural development from
lost wax I guess, but a bit over-complex with lots of extra kit required

but my absolute favourite was https://youtu.be/ZbNim7ix4Rc

[crust]

This has escalated nicely, rapidly becoming a favourite thread.

Rob, now I want bat shaped pancake things :( great video, really entertaining

:thumbsup:

[Mr Gazza]

This has escalated nicely, rapidly becoming a favourite thread

I couldn't agree more Crust.. Some nice brain food here.. :D

Rob you video links were a timely refresher as I'd overlooked the slight matter of a forge. I was still dwelling on how easy it was to melt some lead early last year, for some special little cast parts for a very expensive coldframe commission I built.

A forge doesn't look like rocket science though and I do happen to have a hoover that can blow. I can't work out the best thing for a crucible yet?

I can't wait to get cracking on this, but sadly it looks a long way off yet, what with everything and all that!! :dizzy:

[slob]

As previously mentioned as an indicative pricing and for interest’s sake, I don’t think services in Germany is feasible anymore once postage, VAT, duty and courier processing fees have been added
The first finned flange I posted a pic of (post #48 above) was quoted at €447 for 10 units

I simplified the design to the 6 fins you mentioned with a more ‘petal-like’ look, the price dropped to €357
http://www.thelasturl.net/img/M900_Exhaust_Flange_Fin2.png

I then smoothed all the edges that were feasible (without completely breaking the CAD model) and the price goes up again to €451
http://www.thelasturl.net/img/M900_Exhaust_Flange_Fin2smooth.png

I also altered the flattened one after seeing your pics but didn't bother pricing, it'll be similar to the original 'Nasher design'
http://www.thelasturl.net/img/M900_Exhaust_Flange_Flat2.png

They quote €9 - €12 to 3D print a plastic 1-off, which could be used to test fit or as a plug for a mould, although I imagine casting four at a time would be the way to go… if my mate ever gets his 3D printer operational again, they’d be free though. I'd love to have a go at casting, when we can safely mingle and it's a little warmer outside.

On the plus side this is improving my CAD skills no end, playing with these and complex rocker cover designs,the Mag. finned ones look much taller than OEM, maybe to allow ridiculously lumpy cams? I haven't go one I'm ready to price for CNC yet, I just started with a square on photo of a gasket and superimposed the model over it.
I agree the easiest way to go, for casting, would be to start with an OEM one and stick MDF fins on/filler to make a plug, I'd also add 0.25-0.5mm to the gasket face so there's enough excess to mill off on the finished part.

[Darkness]

I’m sure I saw some of the finned covers in Stafford’s workshop some time ago.

[slob]

just thinking about it , using an OEM part to make a plug is problematic, myfordboy mentions oversizing the model by 4% to allow for shrinkage, easily done with CAD ... select part, then menu > scale

[Mr Gazza]

I'd thought about the shrinkage, but I thought he said 2%? Either way it's about a mil all round on a valve cover.
I thought about gluing a 1.5mm ply "gasket" on the gasket face and leaving that about a mil or whatever, oversized on the outline, then either adding filler carefully round the periphery or gluing a strip of thin plastic of some sort round the edge.. Maybe even roll some plasticine out to a thickness and add that? It's only the overall of the gasket face that would matter I think.
The inside could be carved out with a burr if required for clearance or at least to save some weight.

Your models are looking better and hats off to your CAD skills. Hand filing the rounds on the fins would save a lot of both cadding and machining. Agreed there are plenty of UK based CNC outfits.

Equally as easy to add mdf fins to an exhaust ring for a pattern? Shrinkage probably not an issue on those?

Yet another way to do this is to make a physical model with oem parts with bits stuck on, then get it "cloud plotted". Some of the CNC outfits have that capability.

[slob]

Yup, you're right, 2%

[crust]

You'll be needing one of these then. :)

https://www.artisanfoundry.co.uk/product_info.php?products_id=206

One of my mates has a showmans steam engine, getting parts made usually involves a lot of discussions about shrink rates and how its not always as simple as adding a percentage.

We have the same issues with plastic part design and mould tools.

The material does not shrink universally in the same direction, so in the case of the fins on the exhaust flange it will shrink to the center of the fin causing sinks around the internal face.

[slob]

Something like this maybe?

http://www.thelasturl.net/img/M900_ValveCover_Fin.png

[Mr Gazza]

Good innit. :thumbsup:
Fins are spot on. There seems to be at least two versions of the finning on the bevels. Some have the centre three fins raised quite tall at the crankcase end, others are just like your model.
I'd so love to get stuck into this project, but business is booming at the moment and spare time has evaporated! I'm not complaining about that as it will suddenly dry up one day, but all work and no play makes Gazza a frustrated boy!

[Luddite]

I'm really impressed by your CAD skills, Rob. I used to enjoy technical drawing at school but it would take me about three weeks to draw one bolt!

Seeing your creations, I'm almost tempted to get a computer just to have a play around myself...

[pooh]

Slob
Could the valve covers not be plastic printed using high temp material?

Pooh

[Mr Gazza]

Pooh. I think you can have just about whatever you want.
When UKMOC had a VIP tour of the BBMF at RAF Coningsby, we also had an extremely privileged tour of the BAE hanger where the Typhoons are serviced and commissioned.
We were told by the head honcho that the canards (fore planes) are 3D printed in Titanium with a honeycomb interior.

[slob]

SLS printing in exotic materials is seriously expensive! In theory ABS would be OK, FDM printer head runs at 240-290 deg c for ABS, your outer cylinder head shouldn't get that warm... I wouldn't risk it in practice!!!

[Luddite]

SLS printing in exotic materials is seriously expensive! In theory ABS would be OK, FDM printer head runs at 240-290 deg c for ABS, your outer cylinder head shouldn't get that warm... I wouldn't risk it in practice!!!

The valve covers on my Evo are plastic (I replaced one with an MVS aluminium version). I just looked inside the old one hoping to see a resin identification code but, apart from the Ducati logo and the date code, there was no clue as to what they're made from. So I'm none the wiser! :confused:

[slob]

I'd guess ABS but they'll be injection moulded, the other potential problem with FDM is strength varies depending on the direction they're printed in, this can be compensated for my including a kevlar strand in the material but that involves a much more expensive printer. For production parts from a major manufacturer they do all sorts of FEA which is way beyond my current knowledge and skills.

[Albie]

We used to use glass fibre reinforced nylon in some very hard products when I was in plastic moulding 25 years ago. Hard as nails. Delrin also.

[Mr Gazza]

Ain't modern technology a wonderful thing?
I think that since I'm not building a Eurofighter, the home casting method appeals to the Neanderthal in me.. :mand:

[crust]

I wouldn't recommend ABS for engine components, it's softening temp can be as low as 85C depending on grade.

For higher temps we use glass filled nylon.

[slob]

I’m with Gazza, I want to have a go at Ally casting (he says with a sigh, looking at it p!ss!ng down outside my window)

[slob]

The valve covers on my Evo are plastic (I replaced one with an MVS aluminium version). I just looked inside the old one hoping to see a resin identification code but, apart from the Ducati logo and the date code, there was no clue as to what they're made from. So I'm none the wiser! :confused:

Aluminium, so heavy!

http://jcpakbikes.com/ncrvalvecover/preview/img_0644.jpg

http://jcpakbikes.com/ncrvalvecover/preview/img_0648.jpg

http://jcpakbikes.com/ncrvalvecover/preview/img_0647.jpg