Topic: Handmade steam engines.... on a budget (Read 49421 times)

Mad_Mike · « **Reply #75 on:** November 01, 2012, 03:40:03 pm »

I then filed up the crank to clean it up a bit with a file and took a bad photo

Mad_Mike · « **Reply #76 on:** November 01, 2012, 03:43:47 pm »

I drilled a tapped the piston, this where the small end of the conrod will connect, itl take an m3 bolt which will screw inside. I also made the conrod, its simply to peices of 3mm brass tube with a 2mm dogleg connecting them, the dogleg is to alow for the offset postions of the crank and piston.

Mad_Mike · « **Reply #77 on:** November 01, 2012, 03:47:37 pm »

a bit of an issue i had was working out what i could use as a fly wheel. I remembered i found something at a freinds house that i thought would come in handy one day. A coffee mug tree. I bust the circualr base off it marked out the centre and drill an 8mm hole. I used the same tube which the crank case is made out of and drill a 3mm hole in it. I then tapped and drilled a hole in the crankshaft.

Mad_Mike · « **Reply #78 on:** November 01, 2012, 03:50:23 pm »

I then cut down the tube and soldered on a keyway type lug to it, The tube was pushed inside the hole with the key way lug inside the wheel. I then filled the gap and fixed the fly wheel to the tube:

Mad_Mike · « **Reply #79 on:** November 01, 2012, 03:55:18 pm »

I used a disguarded peice of chair leg from a sofa and made a mounting block for the engine to sit on so the fly wheel has enough clearanc. The fly wheel is excessive but i needed something heavy and round plus it was free. The engine was assembled and the excess base that i left on earlier was cut off. The block and engine was then glued to a plywood board.

Mad_Mike · « **Reply #80 on:** November 01, 2012, 03:59:55 pm »

I suppose now your all wondering if it goes

Mad_Mike · « **Reply #81 on:** November 01, 2012, 04:25:45 pm »

heres some youtube to watch:
http://www.youtube.com/watch?v=tw1XjAss1n4&feature=plcp

Mad_Mike · « **Reply #82 on:** November 03, 2012, 02:53:05 pm »

Im about to start building the 4 stroke is anyone interested in a build blog or should i just show the results when ive finished?

boatmadman · « **Reply #83 on:** November 03, 2012, 03:38:58 pm »

I think its fair to say we would like to see a build blog!

You seem to have 'the knack' with these things, most of us struggle even when machines are available for metalworking!

Ian

hammer · « **Reply #84 on:** November 03, 2012, 07:35:13 pm »

YES PLEASE!! I will look forward to it.

Mad_Mike · « **Reply #85 on:** November 03, 2012, 07:52:19 pm »

Ah good, i wasnt sure i thought people would have said more when i did my last one.
I must admit im having issues and possibly bitten off more than i can chew

There are some hurdles to over come which a re bit higher than i expected, Ill write something up later.

Mad_Mike · « **Reply #86 on:** November 04, 2012, 01:04:38 am »

Unlike my plastic card engines which were the first succesful attempt this engine is the first ever attempt at building an IC engine there fore dont get too excited

. Now ive got that bit out the way to save you all from possible disapointment ill show you what ive been doing. First up the valves and ports. Initially i made my mind up to use 2 elbows, one for the inlet and one for the exhaust, peiced togeather from 3 seperate thickness of ks tubing. Heres my first one:

Mad_Mike · « **Reply #87 on:** November 04, 2012, 01:18:14 am »

It went togeather quite nicely it worked and sealed properly too seamed like i was at a good start. It was my intention to make 2 then solder these into a cylinder end cap, but im using 12mm bore cylinder and both of them would have not a) fitted and b) held togeather while soldering them in. I quickly scrapped this approach and started again. That idea was simple and managable with hand tools, but i would have struggled around them at later stages of the build. There was nothing else for it I had to go all out and make a complete cylinder head from one peice, which for simplicity i was trying to avoid. First i needed to drill the ports i took a 12mm peice of round bar which fits inside my 1/2 inch tube. I started by marking out with a ruler and dot punch the holes i would drill, it didnt work, the position of the holes werent where i had marked them. To get the holes exactly where i needed them i glued 2 6mm ks tubes onto each other then glued them to the end of the bar.

Mad_Mike · « **Reply #88 on:** November 04, 2012, 01:23:25 am »

I then flooded the area with ca glue and splashed a smal handful of bicarbonate of soda on it. For those of you who dont know, bicarb makes ca glue set instantly and rock hard. Hard enough to warrantly being ground off! Once it had set i used the tubes to steady a 5mm drill bit, which i used to mark out where i wanted the holes to be for the ports, i then dont punched them and piloted them with 1.5mm drill bit.

Mad_Mike · « **Reply #89 on:** November 04, 2012, 01:29:32 am »

Starting with a 2mm bit i expanded the holes and drilled roughly 20mm deep, i then went to a 3mm bit and drilled another 20mm deep. I then changed to a 4mm but on drilled 10mm deep and continued to go up by 1mm increments till i had bored out the ports and the valve seats. At the bottom of the port is the 3mm hole, this is where the valve stem goes threw. My marking out had moved again, and warrantied one port to be bigger than the other, it worked out in a way because rather than having 2 ports of the same size i got 1 large inlet port and 1 smaller exhaust one. Every cloud an all that.

Mad_Mike · « **Reply #90 on:** November 04, 2012, 01:44:44 am »

The next thing i needed to work out was how or even if the ignition would work inside the combustion chamber. I bought from the pound shop a cheap candle lighter. I took it to bits and sure enough inside was the electric igniter, the butane tank and a very handy nozzle on a tube, which is conviniently made of brass and will go nicely into my engine. I drilled a simple hole from the side of head into the combustion chamber. This is where the wire for the ignighter will go, it will earth on the engine itself.
Now theres a bit of a jump because i kind of got carried away here. After i drilled the holes into the combustion chamber for the valve seats i needed to drill into the head side ways so that the ports went threw an curve to get outside. To do this i filed 2 flats on the side of the round bar, dot punched, piloted and then bored them out till they made the contact with the other holes. If you understand what i mean. I cant think of any simpler way of putting that

I used 2 m3 countersunk screws as the valves and solderd 2 vertical 4mm ks tubes to the top of the head as valve guides. The valves are held in with pen springs and nuts.

Mad_Mike · « **Reply #91 on:** November 04, 2012, 01:50:32 am »

Th exhaust valve fitted perfectly instantly, the inlet not quite so well, it need more drilling and fiddling with, its now slightly higher in the head than the exhaust, I dont think it will make any difference, or at least a noticeable one. It doesnt look tidy now, which it did before, On the plus side the head is about finished and the valves work. The tube is going to be the cylinder, the 20p is just for scale. I can see now this is going to be quite a long build. Ive got to do the valve train next, that will be difficult.

Mad_Mike · « **Reply #92 on:** November 04, 2012, 11:37:53 pm »

Today ive made some massive headway and now its time to write up what that was.
Before all the fiddly bits could be done I had to work out how the basic structure of the engine would be done. I had some ideas but turning them into practice was harder than i thought. Anywa i made start. Firstly I started cutting up some lengths of 1/2 inch brass and started soldering bits on.

Mad_Mike · « **Reply #93 on:** November 04, 2012, 11:42:27 pm »

I wanted the engine to be partable down the centre so that the crank and cam shaft can be taken out, I decided that the cylinder would be the best point to join the 2 halves. I drilled and tapped the end of one of the 1/2 inch bars. Then soldered the cylinder to it and the head to the cylinder.

Mad_Mike · « **Reply #94 on:** November 04, 2012, 11:46:05 pm »

I cut the end i soldered the cylinder to and mounted the hole part further up the 1/2 incha bar. I had allready pre marked and drilled the holes, i screwed the cylinder to the bar with some counter sunk bolts. After one half was screwed on, the other half of the engine was then soldered to the cylnder.

Mad_Mike · « **Reply #95 on:** November 04, 2012, 11:50:18 pm »

The 2 bits that jut out at the top will hold the axle for the rocker bar. I was intending on the cam acting directly upon the valves, but the valves do not slide up and down in a well fitted hole and they would have moved all over when a cam lobe passes. It seemed logical to then go with rockers,

Mad_Mike · « **Reply #96 on:** November 04, 2012, 11:51:50 pm »

The rockers and bar were then fixed into place

Mad_Mike · « **Reply #97 on:** November 04, 2012, 11:55:10 pm »

next up was a cam. To do this i took a peice of 3mm diameter brass rode and soldered a peice of scrap brass roughly 2 inches of the way down the end. I then cut of the cam profile for the exhaust with a haxsaw and shaped with a file. Once i was happy with the exhaust i soldered another peice of scrap on and did the same for the inlet.

Mad_Mike · « **Reply #98 on:** November 05, 2012, 12:00:09 am »

I i tested fitted the cam and adjust the valves so that the cam flat spots did lift the valves off there seats till they started to peak. The lobes are as close to 90 deg to each other as i could manage, there is some slight over lap between the closing of the exhaust valve and the opening on the inlet. Im hoping the overlap is not too much and beneficial to the running of the engine. I think the hard bit is done now. All it needs is the timing gears putting on but ill do that later.

Mad_Mike · « **Reply #99 on:** November 05, 2012, 12:02:25 am »

Ive started working on the bottom end, ive completed the piston so far. Theres still a long way to go though. thats all for now.

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Author Topic: Handmade steam engines.... on a budget (Read 49421 times)