# Silver Bullet in progress



## Mosey (Feb 27, 2010)

;D ??? I am posting some pictures of my Silver Bullet that I have been working on for many years, off and on. I am now motivated to finish this little guy, and see it run. This is more a voyage of discovery and learning. Oh, did I mention that there have been mistakes along the way for this beginner. Take a look and please let me have your comments, critical or otherwise.


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## Mosey (Feb 27, 2010)

Mosey  said:
			
		

> ;D ??? I am posting some pictures of my Silver Bullet that I have been working on for many years, off and on. I am now motivated to finish this little guy, and see it run. This is more a voyage of discovery and learning. Oh, did I mention that there have been mistakes along the way for this beginner. Take a look and please let me have your comments, critical or otherwise.


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## chuck foster (Feb 27, 2010)

looking good !!!!

can't wait to see it run

chuck


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## stevehuckss396 (Feb 27, 2010)

Finally got you to post it up. Looks very cool!

Steve


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## Mosey (Feb 27, 2010)

?Steve, I want to discuss the next steps in making this engine with you. Should I email you, or put it on this post?


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## bearcar1 (Feb 27, 2010)

Post up here, we all want to tag along on this ride, at least I do. ;D

BC1
Jim


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## stevehuckss396 (Feb 27, 2010)

Mosey  said:
			
		

> ?Steve, I want to discuss the next steps in making this engine with you. Should I email you, or put it on this post?




Both would be fine. I will help all I can but don't limit your self to just me. There are some extremely talented people here that will be glad to help you also.


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## Mosey (Feb 27, 2010)

Here goes.
The method Bob suggested for the water pump was to make it out of a large rod (1-1/2") turning and boring in the 4-jaw. I suspect he may not have used or liked a mill.
Here's my proposed method.
Do all the boring and layout on the mill table, rod vertical in the vise, using the DRO's for layout, after centering it of course. Start with a near finish diameter rod, 7/8" diameter. Make the backing plate from just that, 1/8" thick plate, separately. You still have to make the backing plate and the rear of the housing really flat and mate together. A little water-pump gasket cement, or other sealant might be needed. You could easily make the backing plate, mate it to the housing, bolt it to the back of the housing and bore the shaft holes. Take off the plate, then bore the 2 gear holes. Make sense??
Then you can turn that eccentric nose for the output shaft on the lathe in the 4 jaw of course.
By the way, I make my gears from scratch because I am too dumb to buy stock. Already made the timing gears, so what's a few more. They are fun. I make hobs, heat treat them, and cut away. After about 3 or 4 times around the dial in the rotary table you have them at full depth of the tooth cut.
By the way, I already see that this really helps me learn, because I have to think out what I am going to do before posting it. Eureka!!


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## Speedy (Feb 27, 2010)

keep us updated 

also, both pistons go up and down together? but one just fires on each revolution?


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## Mosey (Feb 27, 2010)

Speedy  said:
			
		

> keep us updated
> 
> also, both pistons go up and down together? but one just fires on each revolution?



According to the plans, the crankshaft is designed with both mains in line on a common axis. Now I don't know how we are going to get them to fire correctly??


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## stevehuckss396 (Feb 27, 2010)

They fire as follows.

0 degrees 1 fires, 2 starts intake stroke
180 degrees 1 starts exhaust stroke, 2 starts compression stroke
360 degrees 1 starts intake stroke, 2 fires
540 degrees 1 starts compression stroke, 2 starts exhaust stroke.
720 degrees 1 fires, 2 starts intake stroke

You get a power stroke every 360 degrees.


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## Mosey (Feb 27, 2010)

Does that mean I have to distribute the sparks to the plugs separately, cause the ignition is by breaker off the camshaft, once per revolution. Or do you waste a spark and let the opening and closing of the valves control combustion? I am very unsure here.


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## kf2qd (Feb 27, 2010)

Classic wasted spark setup. Fewer parts, fewer failures.


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## Mosey (Mar 13, 2010)

I am working on building the water pump, and have been sidetracked by some confusion in the plans.
The body of the pump is .780"
The 2 gears are supposed to be .250" OD, running in .251" bores.
Face .220
10 tooth
Bore .125" shaft
PD .315"
 and 
the gear centers are supposed to be .315" so that the gears mesh with each other their full tooth depth. This obviously doesn't work.

So, I need to enlarge the gears so that they actually overlap their tooth depth. When I figure out what size gears to use I will further post this info.

I have been test boring the gear bores to learn how to handle these HSS boring bars, and find cuts of about 5-10 thousands at a time at the slowest spindle speed works well (brass).

Also, what do you think about mounting the gears on the shafts with tiny Woodruff keys instead of the Loctite? I know that the Loctite will work, but are we not building these tiny engines to have fun? and wouldn't making little keys be fun? and show off to our friends? Actually, MSC has them 1/16" x 1/4". Hmm.

By the way, why does that guy on the MIT videos raise the knee to bore and drill, when the quill is much better IMHO. My knee doesn't have stops. My quill does and it can be set to bore to a fixed depth, and it's easier to control and move up and down? Please enlighten this newbie about drilling and boring on the mill.


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## kuhncw (Mar 13, 2010)

I pulled my Silver Bullet drawing for the water pump and see different numbers. The drawing says REV 2 and the date is 15 April 2000.

The body dia checks at 0.780. The gear pockets say bore 0.343 dia by 0.220 deep. Gear centers are shown as 0.281. 

The gears are shown as Berg part number PW32B-9, OD 0.343, and PD0.2812

I have not checked the numbers to see if things mesh, I'm just letting you know what is on my print.

Regards,

Chuck Kuhn


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## Mosey (Mar 13, 2010)

kuhncw  said:
			
		

> I pulled my Silver Bullet drawing for the water pump and see different numbers. The drawing says REV 2 and the date is 15 April 2000.
> 
> The body dia checks at 0.780. The gear pockets say bore 0.343 dia by 0.220 deep. Gear centers are shown as 0.281.
> 
> ...


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## kuhncw (Mar 13, 2010)

It sounds like you have the correct information on your plans. My drawing shows 4/15/2000. I'd just written the date in a different way in my post. That must be the date of the original drawing and my drawing shows no date for the revision. What revision number is on your two water pump drawings?

Regards,

Chuck


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## Mosey (Mar 13, 2010)

The drawings both have REV 0 on them. One of the them is the sheet #SB-18, 4/15/00, and the other is WP-1 12/12/00. I keep one set in the shop and one in the office. Obviously Bob gave me the later WP-1 and I forgot I had it years ago. He also gave me several other explanatory sheets, such as ones for the radiator.
If you have the plans for the Silver Bullet, did you build it? and would you share your model with us?


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## kuhncw (Mar 13, 2010)

The Silver Bullet is next on my build list. Currently I am finishing up a single cylinder hit & miss and I'll post some photos of it in a few weeks. I have taken a few squaring up cuts on the Silver Bullet block. Unfortunately I like to modify engine designs and that complilcates things. I want to build the Silver Bullet with the pistons traveling 180 degrees out of phase which will change the cam and the igniton. I plan to make the cylinder block about 0.25 taller than print. Why cut off all that good aluminum? That means longer rods. So anyway, I've got some design work to do and then I have to remember what I've changed. Once I get going, I'll post some progress notes. It will be a couple months though.

Good luck with your build, and please keep us posted.

Regards,

Chuck


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## Mosey (Apr 27, 2010)

I have the water pump almost done and will put up some pics shortly. Does anyone remember how to find the nice article on making hobs and cutting gears that I think was in Model Engine Builder magazine about 5 years ago? Nope, it is Strictly IC magazine, Vo. 7, No. 40, August/September 1994.
I will make the 2 water pump gears when I find it. I know there are gear wires available from Berg, but I enjoy making those little guys.
Then onward and upward for the fan assembly. 
I apologize for the sloth, but work and life intrudes you know. Anyhow, this is really learning how every step of the way for me. Do you think that making a multi-cylinder engine from billet is such a great idea for a beginner? My second engine, after an Upshur single. He was a great gentleman I had the privilege to know.


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## stevehuckss396 (Apr 27, 2010)

Mosey  said:
			
		

> I have the water pump almost done and will put up some pics shortly.
> 
> Do you think that making a multi-cylinder engine from billet is such a great idea for a beginner?



I look forward to seeing the pics. Nothing wrong with making a billet engine. No castings to screw up.


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## Mosey (Apr 27, 2010)

Sorry, I only meant that the parts outside the block are from billet, as it is a casting kit of course.


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## el gringo (Feb 20, 2011)

Chuck,
My silver bullet is coming together nicely. I am going to make the cam next.
My question is what holds the cam in place axially and why the split front brg? Bob says it is for easy removal? This is my fourth Bob Shores engine and the beat goes on.......

Ray M


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## Mosey (Jul 30, 2011)

Well, I finally am back to work on the Sllver Bullet.
I am working on the fan, which has been duly reported on another topic. Here are some pics of my first attempt to mill a 9 blader. Critiques and comments are welcome. This is how rank amateurs do it.
I am using the universal table tilted to 30 degress, Sherline RT, and 2 mini-clamps. I think I need the elves to come in as this is tiny stuff. I had to align the center of the RT with the center of the mill spindle at the height of the top of the work piece. I have to move the clamps as I rotate the table to clear them.


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## stevehuckss396 (Jul 30, 2011)

Looking good so far!!


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## metalmad (Jul 30, 2011)

go Mosey :bow:
Pete


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## Mosey (Jul 30, 2011)

Well, nobody rose to the question implicit in my setup. When the table is tilted, then the axial center of the RT and the work is only aligned with the spindle axis at 1 point where the 2 axis cross. I set it up to cross at the top surface of the workpiece.
Now I plan to drill a small center hole in the fan hub, flip it over and realign with the spindle axis at the new top surface of the hub. Then mill the other side of the blades. Also, have to align the fan blades so that they are milled to match the other sides. Piece of cake right?

Comments are invited.


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## stevehuckss396 (Jul 30, 2011)

Mosey  said:
			
		

> When the table is tilted, then the axial center of the RT and the work is only aligned with the spindle axis at 1 point where the 2 axis cross. I set it up to cross at the top surface of the workpiece.



What?

I trust you have it under control.


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## Mosey (Jul 30, 2011)

Trust me! The check is in the mail.


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## gbritnell (Jul 30, 2011)

Hi Mosey,
 I have been following the conversation between you and Steve about fans and would just like to interject my thoughts. While I certainly applaud the effort that you are putting into your fan I think that you are making more work for yourself than necessary. 
 You could cut the fan out of a piece of flat stock and then as was mentioned, make a curved buck from a piece of wood and press the curve into the blades. Drill the center hub area for mounting holes and screw it to a machined pulley. 
 That's the way the full sized ones are made,(before plastic). Attached is a picture of my Holt fan. It was made as I describe.
 As far as your setup, it looks fine to me although instead of moving the big clamps around I think I would have made some small ones that could be moved more easily. 
gbritnell


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## Mosey (Jul 30, 2011)

You're right, of course. I did want to see if I could mill it, but I think I will follow you're suggestion.
Thanks.


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## Mosey (Jul 31, 2011)

gbritnell  said:
			
		

> Hi Mosey,
> I have been following the conversation between you and Steve about fans and would just like to interject my thoughts. While I certainly applaud the effort that you are putting into your fan I think that you are making more work for yourself than necessary.
> You could cut the fan out of a piece of flat stock and then as was mentioned, make a curved buck from a piece of wood and press the curve into the blades. Drill the center hub area for mounting holes and screw it to a machined pulley.
> That's the way the full sized ones are made,(before plastic). Attached is a picture of my Holt fan. It was made as I describe.
> ...


Stainless, or Alum? Gauge?
By the way, those clamps are only 1-1/2" x 3/16" thick. I got them from an auction and they are hardened. Very nice. Smaller??


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## Dave G (Jul 31, 2011)

Hi Mosey, I built the Silver Bullet about 10 yrs ago and it has been a good runner. I built the radiator to Bob's design and it has a 4 blade fan for cooling which it doesn't do very well. Mine will get quite hot (200 degrees) fairly quickly. I think the radiator is of sufficient size but the fan doesn't pull much air. A good multi blade fan that is shrouded would help a great deal.
The water pump is built to Bob's specs also using pinion stock with an o-ring between the pulley and housing for sealing which works alright. It seems to move plenty of coolant as my coolant lines are clear and you can see the coolant flow. I don't normally run my engine long, maybe for 5-8 mins before shutting off. The Silver Bullet was my first IC engine build and remains one of my favorites. I hope you will enjoy yours as much as I have mine. Dave


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## Mosey (Jul 31, 2011)

Dave G.,
How nice of you to tell me about your SB! Encouraging.
I am feeling my way through slowly and having a great time. I had to get my machines and my skills up to snuff, so that has slowed me down as well, but I'm chugging now.
I will take pictures so the other newbies can go along with me.
I will definitely make a good multiblade fan, and think about shrouding it.
I have the pump made and am making the gears from scratch, which I enjoy.  :



Mosey


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## gbritnell (Jul 31, 2011)

Hi Mosey,
I would stay with aluminum. Less rotating mass. As far as gauge, I would say around .032 should be more than sufficient for anything up to 2.00 diameter. Once the curve has been pressed into it, it will become much stiffer.
gbritnell


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## Mosey (Aug 1, 2011)

Dave G  said:
			
		

> Hi Mosey, I built the Silver Bullet about 10 yrs ago and it has been a good runner. I built the radiator to Bob's design and it has a 4 blade fan for cooling which it doesn't do very well. Mine will get quite hot (200 degrees) fairly quickly. I think the radiator is of sufficient size but the fan doesn't pull much air. A good multi blade fan that is shrouded would help a great deal.
> The water pump is built to Bob's specs also using pinion stock with an o-ring between the pulley and housing for sealing which works alright. It seems to move plenty of coolant as my coolant lines are clear and you can see the coolant flow. I don't normally run my engine long, maybe for 5-8 mins before shutting off. The Silver Bullet was my first IC engine build and remains one of my favorites. I hope you will enjoy yours as much as I have mine. Dave
> 
> Dave,
> ...


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## Mosey (Aug 6, 2011)

gbritnell  said:
			
		

> Hi Mosey,
> I would stay with aluminum. Less rotating mass. As far as gauge, I would say around .032 should be more than sufficient for anything up to 2.00 diameter. Once the curve has been pressed into it, it will become much stiffer.
> gbritnell


I am giving it a go. What do you think of this blank?


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## Mosey (Aug 6, 2011)

And now I have formed the fan blades in a die, using a form I turned. I next have to straighten the blades and clean up and polish. Then I will turn a little hub cap, and bolt it to the fan hub with 3 _1-72_ bolts. Hopefully I can make it look less crude, just like the big guys.
Critique is welcome.


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## stevehuckss396 (Aug 6, 2011)

I like it!! Post up a pik when you get it mounted.


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## Mosey (Aug 12, 2011)

Here are some progress pics of the fan and water pump mounted.


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## Groomengineering (Aug 13, 2011)

Looking good Mosey! Thm:

Cheers

Jeff


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## steamer (Aug 14, 2011)

Mosey  said:
			
		

> Well, I finally am back to work on the Sllver Bullet.
> I am working on the fan, which has been duly reported on another topic. Here are some pics of my first attempt to mill a 9 blader. Critiques and comments are welcome. This is how rank amateurs do it.
> I am using the universal table tilted to 30 degress, Sherline RT, and 2 mini-clamps. I think I need the elves to come in as this is tiny stuff. I had to align the center of the RT with the center of the mill spindle at the height of the top of the work piece. I have to move the clamps as I rotate the table to clear them.




Hey Mosey,
Something to consider in the future.  How about doing the rotarty table job like this. Mount a sacraficial aluminum plate to the top of the RT.  In this plate turn or mill concentric grooves over the whole face. Once done face it off clean.  Now, super glue your work piece to the plate.  NO clamps

To take it off, take the plate off and take it out side and gently wave a torch at it until you can wring the part off with a rag. It will clean up with Acetone once it's cool.

Or you can go old school, and mount the part with Shellac....I'll let Tonybird tell us about that.

Buy the way...+1 for doing the jfan blade job like George describes

Dave


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## gbritnell (Aug 14, 2011)

Hi Mosey,
Very nice job on the fan. On all of my water cooled engines the specifications are different, bore size, number of cylinders, radiator size, shrouded fan, non shrouded, so I don't have a good set of specs to work to. I do know that these little things get hotter than one would think and it takes a combination of all the elements to keep them somewhat cool.
gbritnell


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## Mosey (Aug 14, 2011)

The nice thing about this forum, is that when a person like me with limited expertise produces something obviously not perfect, he gets cheers for trying (see below), and encouragement to keep at it. Thanks.
The fan was a challenge, in that it kept moving on the table until I discovered that I should mill out the spaces between he blades first, and then go back to milling the deep gullets down to the hub. I finally ditched the cover plate, not needed. With 9 blades, the neck where the blades connect to the hub are a little too narrow, weakening the blades. I may try again with a few less blades, but it looks great with 9. Perhaps Stainless would be better, even though it is a ***** to machine in such thin sheet.
I am still not satisfied with the die I made for forming the curved blades, as it allows the blades to shift when in the press, ending up not symmetrical. I'll come back to that later. I also think that the conical form that I press into the blades has to be mounted on a hinge-pin so it meets the blades exactly on their central axis. By the time I'm done, I guess I could make a real-scale engine. Next will be the radiator from the Bob Shores kit.
Nice suggestion below about the gluing it down to a sacrificial plate.
By the way, if I get lots of heat, I will be in heaven, because that means it is running.


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