First build, an EZ Build

[chucketn]

I'm getting ready to start my first engine build. After lurking here for a bit, I've decided on the EZ Build.
I have downloaded the documentation, and drawings, and have been searching out other builders threads on this project.
I hope I can build something half as nice as I've seen here!
I had my first shock today. Went to the shop to see what I had available in materials. I haven't had to buy much. My Dad was a scrounger and a tinkerer, and I inherited lots of materials from him. He was a maintenance electrician and had a surprising collection of bits, mills, and tools. My youngest brother also works in the same factory my Dad did, and gets me cutoffs occasionally. I have 1/4 aluminum bar and plate for the base and fly wheel. I looked up the price of brass round and aluminum square for the other parts and was all set to order when I saw the shipping! $14 shipping for $18 worth of metal from Online Metals! Not this boy! Anyone know of a more reasonable source in E. TN?
So, I will whack up a piece of brass hex that has been used (and abused) for a drift. It is seriously bent and mushroomed on both ends. As this piece of brass has obviously been stressed, will that affect the machining? Will it distort when machined?
I have a MicroMark 7x14 lathe and a HF X2 mill with a Shumatec DRO-550, a grinder, and a big box store cheap drill press.
I have made a rudimentary rotary table, and a very simple indexer for the lathe. I’ve had the lathe for 3 years, the mill since last Dec.
Can’t wait to get going.
Some of my metal work is here: http://s571.photobucket.com/albums/ss157/chucketn/Machining/
Chuck in E. TN

 

[Deanofid]

Hi Chuck;
That piece of brass will be fine.
With the machines you have there, you're all set to make an engine, and by the looks of the tool
posts you made, you'll have no trouble with the process. Those look good!

What gearing did you decide on for your rotary table? Have you got much more done on it?

Put your engine build pics up here for us. We'll be happy to see them!

Dean

 

[chucketn]

Dean, I settled on a 60 tooth change gear for the rotary table.
I kinda got side tracked on the RT because I didn't have a good dividing set up for making the dial scale. Still working on the dividing setup for the lathe. Need to make a spindle lock to finish that.
Decided I needed another distraction, thus the EZ build. When I have problems to work out, another project helps while I wait for the light to come on.

Chuck in E. TN

 

[chucketn]

Gathering materials for the EZ Build. Here’s what I have on hand:

3”x1/4” steel disk for flywheel
¼” x 2” aluminum for frame, may use a piece of oak for base to conserve metal.
¾”+ aluminum bar for cylinders
¼ brass rod for valve body
1” brass hex bar for piston, bush
¼” bras square for connecting rods.

I do not have ¾” aluminum square stock, and was wondering if I could mill it from the aluminum round, or if the cylinder and valve body even had to be square? What if I milled one flat side and left the rest round?
The brass hex in the picture is the piece I asked about being stressed as it was obviously used as a drift. Both ends were mushroomed. I cut one end off this morning. The whole piece is bent like a banana. ???

Chuck in E. TN

 

[chucketn]

By the way, all of the materials in the previous post are from my late Dad's collection, that alone will make this build special. The only materials to be purchased will be the screws and a tap if I use the listed 4-40. I have not found a 4-40 tap in Dad's stuff... Plenty of 6-32, and 8-32, but no 4-40.

Chuck in E.TN

 

[black85vette]

I always love it when parts are scrounged and adapted. Certainly makes it more personal when they were your dad's. Looking forward to seeing it built.

 

[chucketn]

Got the base cut out, squared up in the mill and all holes drilled with the help of the DRO.

Next, I think I'll work on the piston and valve.

Chuck in E. TN

 

[chucketn]

I decided on a different approach to the cylinders. I made them out of the 5/8" aluminum bar stock I had on hand.
I also spent a couple hours sawing, and trueing up the banged up brass hex stock to make the piston and bush. The investment I made in the Shumatec DRO-550 was redeemed in the work on the cylinders. I don't think I could have made them without it. Only problem, the heat today, and the batteries in my camera died. Pics tomorrow.

Chuck in E. TN

 

[Troutsqueezer]

Chuck,

Nice to see you're taking that big first step although you should know you're setting yourself up for an addiction.

If it were me, I'd steer towards an aluminum flywheel for my first engine. I don't think you need the weight for this design (others can correct me if I am wrong on this) and the steel may be a challenge for your X2. Depending on how much you plan to machine the flywheel, if at all, there will be some wear and tear on your end mills and on the machine at 1/4" thickness. The machine can certainly handle steel but it does take longer to machine and can be somewhat frustrating at times. Same goes for the lathe but that's not to say it can't be done. I guess what I'm trying to say is that for the first run, machining steel isn't as satisfying as machining aluminum or brass.

There are some folks on eBay who sell brass at reasonable prices and will ship for free. I use the term "reasonable" loosely.

-Trout

 

[Deanofid]

Hi Chuck;
Certainly you can make the cylinders out of any shape you like, as long as they will take the needed
surfaces that make the 'running features' of the engine. Put all the holes in the right place, and the
engine won't care at all what the shape is.

Trout has a good point about the flywheel piece, but give it a try anyway. If it turns out to be a pain
to machine you can always use something else. If you get it done, you'll know more about what you
are able to do.

Thanks for the updates!

Dean

 

[njl]

Hi Chuck,

Your frames looking good, you're bringing back memories of my EZ build I did a few weeks back. I went for an ali fly wheel on mine as I had the round stock and it worked just fine but I reckon a bit more weight would be useful if you want it to make it able to run very slowly.

Nick

 

[chucketn]

O.K., I have a 3" or so (it's out in the shop, so I can't measure it) dia. piece of Ally barstock about 4" long. How do I slice a say 1/2' slice of that accurately? I could just clamp it in the bench vise and whack at it with the hack saw, but what is the best way to do it? I don't have a metal band saw yet...
Should I chuck it in the lathe, start the cut with a parting tool and finish with the hack saw?
What I'm trying to say is, I can't cut straight with a hack saw off hand, and don't want to waste hard to come by material with an angled offhand cut that needs so much metal removed to true it up.

Chuck in E. TN

 

[black85vette]

You don't need round stock to make a flywheel. 1/4 inch flat aluminum will do. Punch the center, scribe the circle then cut with a hacksaw to get as much of the corners off as possible. Mount on the face of the chuck jaws (not in them) and use a live center to hold it in place. Double sided tape between the jaws and material can help. Then make light cuts until it is round. A 3" x 1/4" flywheel is plenty for this engine and aluminum works fine. This is a good method until you have a band saw to cut round stock.

 

[Troutsqueezer]

Chuck, I went through these same conniptions a short time ago. There were varying opinions on the best way to go. Caveat: Mine was perhaps the most dangerous.

http://www.homemodelenginemachinist.com/index.php?topic=9084.0

-Trout

 

[chucketn]

Trout, that's what I love about this list. All the advise and suggestions, you have to find the way... Gets me thinking.
Too darned hot to work out in my un-airconditioned garage today. While in town grocery shopping, stopped at the local hardware store for some 4-40 screws per the design. They didn't carry any! Could have bought a tap and die and made some brass studs and nits... Naw, not this time. I want a runner to impress friends and family. Maybe a little bling, but a runner first. So, I got a new 6-32 plug tap, and pan head socket screws in 6-32 and some 6-32 x 3/16 set screws. Now I have to re-drill the tap holes to #36. Thinking of doing that inside so I can get something done to show. I have the cylinders milled and one drilled for mounting, but only just got started roughing out the piston.
As for the flywheel., guess I will go with ally, though I thought the weight of 1/4" x 3" steel would make a smooth runner.
I hope to get this thing running in 2 or 3 weeks, as I'm going to NY and would like to show it off to my brothers...

Chuck in E. TN

 

[chucketn]

Update for today. Finally got the design of the cylinders worked out. Re-made the piston cylinder today. Also finished the bushing for the shaft, and worked over the flywheel.
I decided to go ahead with the steel flywheel for now, still may change to ally. I burned an hour or so cleaning it up, and making the axil. It's sitting on the lathe with the axil chucked and the tailstock pressed up against the flywheel while the epoxy securing it to the axil cures.
I counter bored the screw holes to be able to use the screws I did buy, that is why I had to re-make the piston cylinder.
Now for an engineering question for those much more knowledable than me. I made the cylinders out of 6061-
T6 aluminum round stock, .816 in dia. I milled a flat .145 from the circumferance to make the flat for mounting to the base upright. You can see from the dia of the round stock it was not big enough to mill into 3/4" square stock. I wanted to save as much material as I could.
Now it is obvious it will be very difficult to utilize a full 1/2" diameter piston, so I will be making the piston smaller.
Now the engineering question. Will the engine run reliably with the piston reduced in diameter? Are the diameter of the piston and valve inter related? If I reduce the diameter of the piston to allow a 1/8" cylinder wall, should I reduce the valve diameter proportionately?
Getting ready to storm, hope this post goes through. Pics to date at http://s571.photobucket.com/albums/ss157/chucketn/Machining/EZ Build/


Chuck in E. TN

 

[Deanofid]

I haven't made this one, Chuck, but from practical experience I'd say if you can make the
piston 7/16" or even 3/8" the engine should run fine, and the valve size called out on the
prints should work just as it is in the print.

I'm betting you're good to go, as long as you don't make the piston too small.

How large can you make it? I mean, what is the maximum diameter that will fit into
the cylinder piece you have there.

Looking good, BTW!

Dean

 

[bearcar1]

Chuck, a good and reasonably accurate method of cutting round stock straight can be had by the simple use of two bands of cardboard wrapped around the piece, secured with tape and with about a 1/16" gap between them spaced just outside your intended cut line. These pieces of cardboard will act as a visual guide and assist you in staying on your line. The part being just slightly oversized and having a rough sawn edge can then be more easily trued up in the lathe. Practicing the art of using a hacksaw properly is always a good character builder as well. ;D


BC1
Jim

 

[Deanofid]

Practicing the art of using a hacksaw properly is always a good character builder as well. ;D
Jim

Oh good. Then I should have a boat load of character! I sure don't have a band saw...



Dean

 

[bearcar1]

You're a character alright Dean, a good one at that Thm:
:bow:

BC1
Jim