Making a Deesil Pattern.

[stevehuckss396]

Things have slowed down at work and I'm back on a normal schedule. One of the things I did while
working was shoot off my big mouth and agree to make a pattern for a crankcase. Well I am finally
getting it done after promising many months ago that I would do it when I got time.

The prez of my metal club Rick does casting demos at the engine shows and some other clubs in
the area. Someone approched Rick at one of the shows about the Deezil engine. This fellow has
one of the castings for the crankcase but is afraid to machine it. He asked Rick if he could cast
practice cases. Well we figured why not. After the cases are cast he could still use the pattern
for his demo's and give the cases away to anyone who wants to build the engine.

Because there is no way to cast the cases exactly like the original, here is the plan. The cases will
be cast with MDMC (Metro Detroit Metalworking Club) on the front of the block instead of DEESIL.
This way the blocks we cast will never be confused with the "real" Deesil cases. The case will
be machined and a new crankcase drawing will be on our website for download. All the other
original Deesil parts will fit. The plans can be purchased on CD ROM from ron over at Model
Engine News.

After reverse engineering the casting I drew up the case in Alibre. Then I assembled 4 cases
on a hub and saves it as a STL file. The STL file was opened in CamBam and all the tool paths
were created. CamBam created some 280,000ish lines of code. I took the Gcode to the computer
in the garage and opened it up with Mach3 and here is how it went.


First roughing pass. The material was provided by Rick. It is called Renboard? It's kind of like a
cross between plastic and wood. It's very dense and stable. Machines real nice.

First pass




Third pass




Fifth pass




Seventh Pass




Ninth Pass




Roughing out complete





The center section was finished using a 1/8 inch cutter. The cutter started on the left side and went down
following the contour of the part. The cutter moved to the right just a few thou and went back up. The
process was continued until the center section was finished.





Then because there were some tight spots to get into, a 1/16 inch cutter was used to finish the rest of the
pattern.





Then the entire thing was cut out to the correct thickness to complete the first of 10 pieces.




The other pieces are simple and should not take long to make.

[Jo]

Wow ,

You make it look so easy. How long did it take to design the pattern using Alibre and then to convert it into a machining program?

Jo

[ths]

Fantastic pattern, Steve, and it looks to have a superb finish. Is shrinkage allowance built in, and is there a draw taper there as well?

I'm not familiar with the engine, is there a link to find out more?

Cheers, Hugh.

[steamer]

Cool Steve!...er ah "Bubba"!   Welcome Back!

I'm watching!

Dave

[maury]

'396, You are doing exactly what I'm trying to set up to do. Very nice work! I have been making all of my patterns in the wood shop, and while it's relaxing and fun, I find my accuracy could be better sometimes, and the complex curves are difficult to match on the cope and drag. CNC solves that.
I'm just getting into Solidworks, an absolutely awesome piece of software, and will be using BobCam for Solidworks.

Been learning tool path options this week. I have a few questions, don't know whether it would be better to take it off line, or share with everyone on the board, may just add a lot of fluff. First off, I had a friend CNC a pattern for ma on my last project, and he used what looks like your Ren Board. Really nice stuff, found Freeman Supply carries it, same place I get some of my other foundry supplies. What tooling do you use to cut it, (HSS or carbide), and what feed/speed would you use to cut it. I want to set it up as a material in BobCad.

maury
www.lonestarengineworks.com

[ScroungerLee]

The finishing pass with a 1/16 bit must have taken a loooong time!  It looks great, I will have to investigate this Ren board material.

Lee

[tvoght]

Steve,
First off, it was good to talk to you in Zanesville in October. Maybe you remember.

Some time ago, I bought the casting for the Deezil form Roger Schroeder. I started the build, and somewhere in the process, I ruined the casting. Since I had already accumulated some stock, and worked out procedures, and made some fixturing, I intended to get another casting and give it another try in the future. Sadly, in the meantime Roger Schroeder passed away.

Anyway, good and interesting work on the patterns.

--Tim

[stevehuckss396]

Wow ,

You make it look so easy. How long did it take to design the pattern using Alibre and then to convert it into a machining program?

Jo

Rough guess?

Draw the case took about 3 hours because I would draw and then machine it in cad. When I finally got it to where I thought it should be I went back and added material for shrinkage and a little to machine off.

CamBam was only about an hour.

Cut time was about 5 hours. It takes a long time to finish when it only steps over a few thou at a pass.

[stevehuckss396]

Fantastic pattern, Steve, and it looks to have a superb finish. Is shrinkage allowance built in, and is there a draw taper there as well?

I'm not familiar with the engine, is there a link to find out more?

Cheers, Hugh.

Shrinkage is considered as well as a 2 degree draft everywhere and all corners have a slight radius.

http://modelenginenews.org/engine_finder.html

Click this link and search for Deesil.

[stevehuckss396]

What tooling do you use to cut it, (HSS or carbide), and what feed/speed would you use to cut it. I want to set it up as a material in BobCad.

I use HSS and usually a ball nose. I run the spindle flat out which is about 3500rpm. I rough cut at 60ipm and finish at 40.

[stevehuckss396]

The finishing pass with a 1/16 bit must have taken a loooong time!  It looks great, I will have to investigate this Ren board material.

Lee

Yeah!  But I wanted to do the entire finish cut without a tool change and there are so many tiny little corners.

[stevehuckss396]

Steve,
First off, it was good to talk to you in Zanesville in October. Maybe you remember.

Some time ago, I bought the casting for the Deezil form Roger Schroeder. I started the build, and somewhere in the process, I ruined the casting. Since I had already accumulated some stock, and worked out procedures, and made some fixturing, I intended to get another casting and give it another try in the future. Sadly, in the meantime Roger Schroeder passed away.

Anyway, good and interesting work on the patterns.

--Tim

If this goes well I'll send a casting your way. Rick always casts at names so if this pattern is ready by then, I'll make sure he saves one for you.

[ths]

Thanks for that link, Steve, a thoroughly entertaining history of two terrible engines! I'm sure yours will will not carry on the weak genes of the line.

I'm assuming that the patterns are for sand casting - are cores involved? I can't see any core prints there, although the runners are very well sized.

Cheers, Hugh.

[stevehuckss396]

Thanks for that link, Steve, a thoroughly entertaining history of two terrible engines! I'm sure yours will will not carry on the weak genes of the line.

I'm assuming that the patterns are for sand casting - are cores involved? I can't see any core prints there, although the runners are very well sized.

Cheers, Hugh.

Nope, no cores. They are small and can be machined in a few hours i'm guessing.

It does have a poor history. I have heard that searches have failed to find even one person who purchased the engine from Gothem and got it to run. There were castings available to build your own so I assume there were engines running at the time.

[DavidF]

After reading the story on the deezil it makes me want to build one and see if it runs and for how long. Would make an interesting contest too lol.

[maury]

'396, another question. I ordered a sample kit of Ren Board form Freeman, looking at their site, the number of different grades made it non obvious which one to get. As material goes, it's cheaper than machinable wax, but still a sizable investment for a whole sheet.

Will you use the Ren Board you machined directly as a pattern, or make a rubber mold and use Repro castable urethane? It seems ramming sand around those small fins may cause some breakage. Also, what do you finish the Ren Board with?

Maury

[zeeprogrammer]

That was an enjoyable read in that link Steve.
Both interesting and entertaining.
Brought back some memories too.

[stevehuckss396]

'396, another question. I ordered a sample kit of Ren Board form Freeman, looking at their site, the number of different grades made it non obvious which one to get. As material goes, it's cheaper than machinable wax, but still a sizable investment for a whole sheet.

Will you use the Ren Board you machined directly as a pattern, or make a rubber mold and use Repro castable urethane? It seems ramming sand around those small fins may cause some breakage. Also, what do you finish the Ren Board with?

Maury

I'm not sure exactly what type board it is. I get scrap pieces from a friend who uses it alot at work. I could try to find out.

I use it directly as a pattern. I spray it with clear coat to seal it. I don't think there will be a problem with the motor mount ears snapping off. I guess time will tell when we put it to work. If there are problems with it I have a nice piece of maple standing by.

[stevehuckss396]

Well I have the pattern completed.You can see on the back side where I screwed it up a little bit. It is
only the runner so I didnt worry about it. The Cases got a little also but that will be machined away.
All that is left is figuring out how to remove it from the sand. I'm not sure what to do. I'll figure out
something. Then 2 coats of clear and done.




The nose pieces are pressed in. I have to ask rick if he wants a radius at the base and if so, what does
he use for a job like that.





These are the rest of the parts. The large piece will form the infeed and the brass pieces will form the boss
on the rear of the case where the fuel system goes.

[DavidF]

Any updates??  I would like a look at the castings...

[stevehuckss396]

It has not been cast yet. The person who will do the casting has had alot going on and has no time to do it. Massive home repairs. I would imagine when the temps here get above freezing he will get the itch. When it happens I will get some pictures posted.

[steamer]

Hey Steve,

Why not mount that to a match plate?  It will support the pattern and runner and make the whole thing a very strong

All a match plate is , is a piece of heavy plywood.   Pattern and runners on one side.....filler spout on the other.......makes it easier to take from the mold too....

 

[stevehuckss396]

Hey Steve,

Why not mount that to a match plate?  It will support the pattern and runner and make the whole thing a very strong

All a match plate is , is a piece of heavy plywood.   Pattern and runners on one side.....filler spout on the other.......makes it easier to take from the mold too....

 

That may very well happen. We were supposed to make some test pours today. We will see if Rick can do it. He has the pattern.

[stevehuckss396]

Well the mold was finally used today. Things could have been better. The pattern worked as expected. The shrinkage was exactly what was expected.

The bad part is I machined the thickness of the pattern what the finished casting should be so everything is too thin. I am a moron! Other than that the sand was not bonding very well and there were problems. I am going to make a new pattern and then I have to figure out why the petrobond is a little loose. More to come.

[steamer]

2 steps forward 1 back....its an old song Steve....You'll get it! 

Don't sweat it bud...

Dave

[swilliams]

This is really interesting Steve and nicely done. Hope the slight hiccup doesn't throw you back too far

Steve

[ths]

That's bad luck, Steve. The curse of Gotham? Any point in making it at 90-95% full size?

Hugh.

[stevehuckss396]

That's bad luck, Steve. The curse of Gotham? Any point in making it at 90-95% full size?

Hugh.

I guess I could but the whole idea was to make the crankcase and have all the original parts fit. I will make another pattern and it will most likely be a match plate this time.

I also have to fix the sand. It doesn't seem to stick together very well. It is brand new sand so maybe it needs to be used some more. I have no idea. Just seems to flake apart easier than it should.

[stevehuckss396]

After reading the story on the deezil it makes me want to build one and see if it runs and for how long. Would make an interesting contest too lol.

Should have enough casting soon. She does have a terrible history.

[stevehuckss396]

Well I went out to make a new pattern but I just don't feel well. It will have to wait until I feel better.

Here is some very poor video of the first pattern of the day that went bad. I'll get it!

<a href="https://www.youtube.com/watch?v=xwVK9QAObNs" target="_blank">http://www.youtube.com/watch?v=xwVK9QAObNs</a>

[vcutajar]

Get well soon Steve.

I am always mesmerised when I see a CNC video.

Vince

[steamer]

Get better bud!   It will still be there when you are!

Dave

[stevehuckss396]

Thanks Men!

It's just sinus trouble and sore throat. I'm losing my voice so the wife and work mates will be happy.

[Ramon Wilson]

Hang on in there Steve - on all counts - health and pattern

I have an interest here - for far too long I have an original Deezil stripped down for measurement awaiting the '5cc treatment'. I look forward to seeing your results.

Get better soon,
Regards - Ramon

[Tjark]

Steve I hope your health is going the positive way.
You made a great pattern on those little engines.
A friend of me has made for an new Zenoah engine an exhaust core mold by CNC in delrin.
This one is in three parts and has to be glued together.
The problem with the petrobond forming sand looks the same I have sometimes.
I use two types off pertrobond sand (there are five type’s available).
One is quite hard when the mold is ready, the other one seems all the time a little flexible when the mold is ready.
With the first type I had never trouble but with the second the errors you have I get a lot off times.
Maybe a little more mulling will work in your case.
I will order the firs type off sand the next time.