Model Engine Maker

Engines => From Kits/Castings => Topic started by: maury on October 24, 2018, 06:58:07 PM

Title: Forest 1889 6 cyl Marine Engine
Post by: maury on October 24, 2018, 06:58:07 PM
Folks, there is a bit of a delay in the work on the Dickson. so I thought I'd spend a few days
working on a back burner design project I've been wanting to do for some time. I am really
fascinated by the work Fernand Forest did on pioneering internal combustion engines. As
some of you know, I scaled the 1888 4 cylinder marine engine and offered a casting kit of it
several years ago.  In "Les Bateaux Automobiles..." Fernand Forest describes a 6 cylinder
marine engine. That is my new design project.

So far, I have the basic outline for the lower part of the engine modeled. There are still many
details to be covered, but I wanted to find out how well I would be able to do with only a small
picture of the original drawings as shown in the book. Luckily, there is a front and side view with
part of the front view sectioned off. The drawing is clear enough for me to measure with a caliper
and scale the parts.Unfortunately, none of the dimensions are legible. I also have a picture of
the engine installed in a boat. Not a whole lot to work from. As best I know, there are no surviving
examples of this engine.

There are several pages of text associated with the engine in the book, but it's in french. If there
is someone out there who would be willing to translate those pages, I'd like the help.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Admiral_dk on October 24, 2018, 09:41:48 PM
If it is on the web - use Google to translate  :cheers:
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: kvom on October 25, 2018, 10:47:57 AM
Email me the text and I'll translate. 
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on October 25, 2018, 08:45:57 PM
Guys, thanks for tuning in.
KVOM. thanks for the offer. There is no electronic copy that I know of, I can scan images of the pages and email them to you. If you are still interested, let me know.

THanks,
maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: kvom on October 25, 2018, 08:53:24 PM
That's what I expected.  Send them.
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 11, 2021, 09:28:49 PM
Well I know this is an old thread, but I want to ressurect this project. I picked up an Ender 5 3D printer this past Christmas, and have been playing around with it. I have enough experience on it now to build an engine-so I believe.

 Over the years, I have also almost completed the Forest 1889 6 cylinder CAD design. Just have a few of the small parts to go. It's been a long time coming, but I have been wanting to build this engine since I completed the Forest 1888 4 cylinder. I will be doing this build on my 3D printer. We'll see how it goes.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Dave Otto on May 11, 2021, 10:07:46 PM
Hi Maury

Are you planning to use the printer for making patterns?

Dave
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 11, 2021, 10:14:49 PM
Dave, About a year or so ago I started making the base pattern on my CNC. I have decided this part is too complex to cast for the purpose of making only one part. So, I am planning to do the build on my 3D printer.

Another reason, I don't have an iron foundry any more, so there is little point in doing castings. I would prefer castings, but I regard aluminum to be no better than plastic.

If anyone is interested in doing castings for this engine, I would be happy to give them the design, and to help where ever possible.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 14, 2021, 02:50:25 PM
3D printing is new to me, so I'll have to do some background work and decision making to start with.

First off, I need to figure out what fastners would be good for this project. After thinking about some, and looking at a few other printed engines I decided to use holes and printed pins for alignment, and bolts for the big parts. I have seen a project that used embedded nuts in the plastic instead of tapped holes. I'm going to use this idea.

Also, holes and pins are a bit tricky in 3D. The printer has a line width of .4mm and a line height of .2mm or greater, using a .4mm nozzle. This isn't the best accuracy compared to what our metal working machines have.

I have done a number of test patterns with some hole sizes and printed pegs with the same diameter as the holes. I have also done a test pattern with embedded nuts of various dimensions to determine what works well. Using this information, I can then adjust the geometry of my model to get the correct hole sizes for the final printed part.

Playing around with this I have also found the holes are a bit fuzzy, so I use a pin vise with a drill to clean out the holes after printing. This gives a nice fit.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: tvoght on May 14, 2021, 04:58:04 PM
I'm watching with interest, Maury. I appreciate your methodical testing to refine techinique.  --Tim
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 14, 2021, 05:50:26 PM
Dave, and Tim, thanks for tuning in.

Another possible project issue is the gears. This model uses a 1:1 set of gears driven off the crank shaft. They drive a lee shaft setup that extends to the engine heads, where a set of 1:2 gears drive the cam shaft. There is also a set of miter gears on the pinion of this second set that spins the governor.

I played around in CAD, Gearotics, and the 3D Cura slicer software for some time to determine whether I would be able to actually print the gears in the sizes I would need. I can make the spur gears on my gear hobber in metal, but not the miter gears.

After several tries, I found I would be able to make useful gears at 28DP. These would make pairs that will work well , but the pitch circles are a bit off from what I need. In Cura, I can scale parts up and down, and scaling a few % I was able to get the dimensions I need.

Here is a Pic of some of the original results.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 16, 2021, 03:21:04 PM
Moving along, I printed the cylinder liners in anticipation of doing the water jacket parts. I wanted to start out making some parts with shorter print times, as I am using a new filament, and I wanted to try out the embedded nuts.

The water jacket parts needed support to print , and that always involves a bit of clean up after the print.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 18, 2021, 02:15:02 PM
I thought I'd try a longer print. The columns take about 8 hours to print, and thy also have embedded nuts.  bit of a bigger challenge. There is some support required for this part also, and will require a bit of cleanup after the print. The Pics show the progress.
maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Dave Otto on May 18, 2021, 02:33:34 PM
That looks good Maury!

So you put a pause in the program that allows you to place the nuts, then continue? I think our Stratasys machines here at work will do that but I have never tried it.
I have used a number of Heli-Coils in printed parts and that is also another good option for stronger threads.

Dave
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 18, 2021, 02:55:35 PM
Dave, thanks for the comment.
yes, the Cura slicer allows various macros to be included in the G-Code. The pause macro is set up to retract the print head, park it at a programmable destination, and resume with a button click.

I initially wanted to use something like heli-coils, but I was unable to find them in 2-56. I could get small metric ones, but then I was unable to find same size metric hex bolts... Thus the embedded nuts. There may be places on the heads of this model where I'll need 1-72 or even 0-80. That being the case, I may just need to use alignment pins and glue.. yuk...

I haven't tried to tap these small holes in plastic, but I suspect it will not end well.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Kim on May 18, 2021, 05:19:14 PM
Embedding the nuts like that is a neat idea!  I'm not much up on 3D printing, but will likely get into it someday.  This is all very fascinating!

Kim
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: gbritnell on May 18, 2021, 05:33:24 PM
Hi Maury,
Good to see you're back. I really enjoy the unique engines you come up with. I'm following along on this one. Looks like it will be very interesting.
gbritnell
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Roger B on May 18, 2021, 07:57:37 PM
Fascinating 3d printing  :)  :headscratch:  :wine1: but currently way beyond me  :old:
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Craig DeShong on May 18, 2021, 10:04:18 PM
Hi Maury

We talked a while back on the phone when I was inquiring on the availability of your Forest 4 cyl. engine.  Great to see you working on a 6! I'll be watching; and my interest in the forest design hasn't waned since we talked.  :popcorn: :popcorn: :popcorn:
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 18, 2021, 11:09:54 PM
Kim, Embedding the nuts is not my idea, but I'm using
it as a best alternative to making my own Press-In inserts.
I haven't tried, but I think it would be difficult to knurl a 1/8"
rod, and then drill & tap it 2-56 a bunch of times.
George, I was never gone, thanks for tuning in. Same for Roger, I hope
everyone is going to enjoy the printing way to build models. If
I still had access to good iron foundry, this engine would be in
castings.
Roger, I hope you can pony up and take my patterns and continue the
Forest 1888. I believe there are still folks out there who want to
build engines with castings. This is the most authentic way to realize
these old engines.

Next will be the base. it's a 2 day and 9 hour print.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 19, 2021, 02:58:25 PM
OK, it's time to brave a really long print. This is a first for me, 2 days 9 hours. I will be making the base for the engine. There are a lot of overhang features, so extensive support will be needed. There are many options in the slicing process, and there is a lot of variability in print time, and support given. I studied these options exhaustively and have chosen the option where the slicer generates a tree structure.  As the print progresses, you will see these wierd structures as they grow into a tree under the overhang. At the top of the tree, a grid is generated as the final support level. There is a 1 layer gap between the grid and the actual part geometry. So as the part geometry sags down to the grid, it is supported. Since there is minimal connection between the support and the part geometry, it is fairly easy to remove. However, the underside of the geometry is somewhat rough compared to the tops of the part.

As with all 3D prints, the first layer is critical. If it doesn't adhere to the build plate and stay flat, the print will fail. I have found that different brands of filament behave differently, and different colors within the same brand behave a bit differently. The particular filament I'm using extrudes quite nicely, but it's build plate adhesion is a bit of a problem. I have to use a layer of glue on the build plate for this particular filament.

Day 1 progress:

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 20, 2021, 05:20:48 PM
Day 2 Progress:

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 21, 2021, 02:55:50 PM
Day 3 Progress -or not-

I woke up on day 3 and checked my printer only to find out the nozzle had clogged. The printer was still running, but no plastic was being extruded. What to do? I didn't have enough filament left on the spool to start it over, and more immediate, the dead would have to be cleaned out.

I cleaned the hot end and replaced the nozzle, but the filament had melted up into the Bowden tube, and I had to replace that too. not that bad, but a big interruption.

What to do about the engine base? it turns out the top surface last printed was clean and smooth, so I decided to take a temporary short cut. I will lightly sand the top and measure it. Then go back into Solidworks and cut the part at the last printed plane. Si I will make a new part starting at this plane and glue it on the lower part. I don't know if this will work well, and I will probably go back and make another base at some time. I think it will be almost impossible to make an invisible glue line.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Kim on May 21, 2021, 05:55:21 PM
That's frustrating!   Two full days into the print and something happens!  :wallbang:
I'm not a 3D printer guy (yet) so I don't have any words of wisdom to offer.  Just some commiseration.

But this sounds like a reasonable way forward, and as you said, you can always try again if you choose to.

Kim

Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 22, 2021, 03:42:36 PM
Kim, thanks for the comments.

The base has been cleaned up a bit, and I glued it together with epoxy.The match is close, but not quite right on. For now it's good enough to proceed... there is no telling what I will run into with the small parts on the heads.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 24, 2021, 02:42:12 PM
With the base printed, I thought I'd start making parts for the crank shaft and it's bearings.
I am able to print the main bearings in the engine color, change filament, and print the oilers all in one part.

i will print the con rod bearings all in one color, as the oilers begin at a lower level from the top of the bearing block.
There are small alignment tabs on the top of the rod bearings to align the con rods. The con rod bearings were a little rough inside, and a bit undersized. A while back I bought a set of adjustable reamers, so this seems to be the perfect use for them.
the bearing cleaned up nicely and gave a good fit to the dim I needed.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: mnay on May 25, 2021, 04:35:52 PM
Maury,
I have not had the courage to make that large of a 3 d print.  What do you use on your build plate to get it to stick?
I use hair spray on a glass plate and it does ok.
thanks,
Mike
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 25, 2021, 04:50:04 PM
Mnay, thanks for the response. I use gorilla glue stick. It may be a bit overkill, but it was the only glue stick I could find on the shopping outing when I needed it. The burgandy filament I'm using is matter hackers professional filament. It makes decent parts, but it is the only filament I've has problems sticking to the bed plate. With the thin support I need, sticking on the initial layers is obviously critical. I've had do do a few restarts with this filament, but I like the color.

A little progress, the crank parts and the crank assembly with the rod bearings is shown below.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: ddmckee54 on May 25, 2021, 08:18:04 PM
Maury:

For embedded fasteners in a 3D print, try something like these.
https://www.amazon.com/initeq-2-56-Threaded-Inserts-Printing/dp/B07BB22SQS (https://www.amazon.com/initeq-2-56-Threaded-Inserts-Printing/dp/B07BB22SQS)
I believe that you mentioned you were using 2-56 fasteners at some point.

You just print the proper size hole and then embed the fastener using a soldering iron, or similar heat source.  They work like a charm and are much easier than trying to design an internal pocket, pausing the print at the right time, and inserting a nut.

I've found that splitting large parts into several smaller parts works best for me.  Losing a 12 hour print 9 hours into the print hurts a lot less than losing a 57 hour print 40 hours into it.  It also gives you the option of flipping the smaller part over on the print bed, eliminating the overhang and the need for support.  It might also make it possible to bolt, and glue, the parts together.  Personally I don't have any problems with a belt AND suspenders.

Don

P.S. I wonder what a bead blasted 3D print would look like?  Kind of like vapor smoothing in reverse.
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 25, 2021, 09:47:23 PM
Don, thank you so much for the link. I searched everywhere for just this kind of insert, but it didn't pop up in my searches. Just what I need. I'm going to order the short and long ones. Maybe with a bit more poking around, I can find 1-72 and 3-48 as well.

Thanks again,
maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: ddmckee54 on May 26, 2021, 03:30:26 PM
Maury:

If you want Imperial fasteners, 2-56 is about the smallest I've found, I just Googled "3D threaded inserts".  (When I tried "1-72 3D threaded inserts" I didn't get any complete matches.)

I've got a butt-load of M3 button-head SS cap screws so I just use M3 inserts.  I did find a link to M1.6 inserts on Ebay, but I don't think that's much smaller than 2-56 is it?

I suppose you could try "rolling your own" by knurling, drilling, tapping, and parting off brass rod - but is that really worth the effort?
Don

P.S. - I just checked McMaster-Carr, and they've got threaded inserts in various sizes down to 0-80 for less than $14USD per 100. (Sometimes they actually DO have decent prices.)
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 26, 2021, 04:31:38 PM
Don, thanks for your continued help. I may want the 1's and 3's for future projects, but for now the 2's will be good. As much as I dislike metric, I would be willing to use them. I build scale model antique engines, and i want to use the tall head scale hex bolts. So if I could find the inserts and bolts in the same size I'd be ok with either metric or Imperial. There are also cases where I could use a through stud with a nut on both ends.

Progress on the engine is slowing a bit, but I have managed to assemble the crank to the pistons.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 27, 2021, 07:52:49 PM
Well, now we have all the major parts for the lower engine. Can't wait to see what the assembly looks like.
maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Dave Otto on May 27, 2021, 09:47:53 PM
That's coming along nicely Maury!

Dave
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 29, 2021, 03:39:37 PM
Dave, thanks for the compliment.

The next part of the engine I want to work on is the Lee Shaft and the gearing for it. This feature is unique to the all of the old engines I'm aware, making it a good modeling candidate. I played with the balance of making gears with teeth large enough to print, but small enough to look authentic. 28DP seems to be a good balance. So far I have printed the crank pinion, and the Lee Shaft driver gear and it's shaft.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: crueby on May 29, 2021, 04:30:41 PM
What is a Lee shaft?
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 29, 2021, 07:55:17 PM
Crueby, thanks for tuning in, and the question.

As with most things, there are probably other names for a Lee Shaft.
A Lee Shaft is made up of two rods tied to two cranks ofset by 90 deg. The shafts are tied to cranks of the same dimensions on both ends. The hafts c/c is equal to the of c/c between the shafts attached to the cranks. The purpose is to transfer motion from the driving shaft to the driven shaft. When one of the rods is pulling, the other is pushing, the 90 deg prevents lockup. I think it works best at low RPM, so it never really caught on in modern engine design, remember, this is 1889, and is designed by a pioneer in engine design. It might be noted, Forrests engines had spark plug ignition, something that had not caught on in mainstream engine design for another 30-50 years or so.

Hope this helps, Soon I'll be posting some pics of the mechanism.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Dave Otto on May 29, 2021, 08:08:28 PM
Here is one in motion if interested.

Dave

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Title: Re: Forest 1889 6 cyl Marine Engine
Post by: crueby on May 29, 2021, 09:24:28 PM
Crueby, thanks for tuning in, and the question.

As with most things, there are probably other names for a Lee Shaft.
A Lee Shaft is made up of two rods tied to two cranks ofset by 90 deg. The shafts are tied to cranks of the same dimensions on both ends. The hafts c/c is equal to the of c/c between the shafts attached to the cranks. The purpose is to transfer motion from the driving shaft to the driven shaft. When one of the rods is pulling, the other is pushing, the 90 deg prevents lockup. I think it works best at low RPM, so it never really caught on in modern engine design, remember, this is 1889, and is designed by a pioneer in engine design. It might be noted, Forrests engines had spark plug ignition, something that had not caught on in mainstream engine design for another 30-50 years or so.

Hope this helps, Soon I'll be posting some pics of the mechanism.

maury
Ah - think I have a mental picture of that. Sounds like an interesting way to avoid needing sets of bevel gears to offset the shaft, simpler parts giving the same result. Thanks!
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 30, 2021, 03:54:30 PM
Dave, thanks for the video. It shows how the Lee Shaft works well.
Is that your engine? I remember you getting castings from me many moons ago.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Dave Otto on May 30, 2021, 05:17:19 PM
Hi Maury
That is Max's engine, I haven't started on mine yet.

Dave
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on May 30, 2021, 06:36:11 PM
Dave, tell Max he did an excellent job on it. It's good to see a working one out there.
maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: crueby on June 05, 2021, 12:12:37 AM
Crueby, thanks for tuning in, and the question.

As with most things, there are probably other names for a Lee Shaft.
A Lee Shaft is made up of two rods tied to two cranks ofset by 90 deg. The shafts are tied to cranks of the same dimensions on both ends. The hafts c/c is equal to the of c/c between the shafts attached to the cranks. The purpose is to transfer motion from the driving shaft to the driven shaft. When one of the rods is pulling, the other is pushing, the 90 deg prevents lockup. I think it works best at low RPM, so it never really caught on in modern engine design, remember, this is 1889, and is designed by a pioneer in engine design. It might be noted, Forrests engines had spark plug ignition, something that had not caught on in mainstream engine design for another 30-50 years or so.

Hope this helps, Soon I'll be posting some pics of the mechanism.

maury
Ah - think I have a mental picture of that. Sounds like an interesting way to avoid needing sets of bevel gears to offset the shaft, simpler parts giving the same result. Thanks!
It was perfect timing to learn about the Lee Shaft linkage, just saw one on an Allis pump engine in the Boston waterworks museum, has the two cranks, 90 degrees offset, one at either end of the engine to drive the shaft with the valve eccentrics. Without your description I wouldn't have noticed what it was or how it works.   :ThumbsUp:
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: kvom on June 05, 2021, 11:59:12 AM
So today you'd just have a belt or chain between the two?
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: Dave Otto on June 05, 2021, 05:52:11 PM
Hi Maury
I'm curious where you came up with the name Lee shaft, Google seems to return nothing?

Dave
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on June 05, 2021, 06:53:30 PM
Guys, thanks for the responses, it looks like i'm mixing a little too much domestic stuff with my shop time.
Crueby, glad I could help.
Kvom, yes. today they probably would use a timing belt. That would be able to operate at a higher speed, and transfer more power to the driven shaft. A vertical side shaft would work also, guess the design could involve the same number of gears as is currently being used.
Dave, I first encountered the "Lee Shaft" in the C.H.Wendel books. It was shown on the Forest & Gallice 5 cylinder engine. I have seen it on pictures of several of Forests early marine engines.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on June 10, 2021, 07:50:39 PM
Ok, getting back in the grove a bit here. The heads are printed now, and so begins the task of making the Lee Shaft, gears,  and a whole raft of small parts. I haven't figured out how to print really small valve springs, so I may make them on the lathe with my spring winder.

These heads would make really nice investment castings, too bad I don't have an iron foundry any more.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: gbritnell on June 10, 2021, 08:22:43 PM
Nice work Maury! It's going to be neat when finished.
gbritnell
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on June 12, 2021, 01:21:22 PM
George, thanks for the compliment. I have my hopes up to have a nice model when finished, but I think I'll miss the rumbeling of a real 6 cyl.

maury
Title: Re: Forest 1889 6 cyl Marine Engine
Post by: maury on June 16, 2021, 09:00:53 PM
OK, Folks, This part went ok, but there was a bit of tweaking the geometry to get the miter gears to fit nice. The vertical shaft will later hold the governor. Having the timing gears, shafts, and cranks in place, I can work on getting the Lee Shaft built and in place. I will be using steel rods with 3D printed rod ends. The rods are way too thin to get a good print, and even if I was able, the plastic would be just too weak. This is getting into the more tricky part of the engine where some really small parts have to fit and work. We'll see how it goes.
maury