Calculating top speed on ice...

[Johansson]

Ha, our goal at the speed events is plain madness. Every thing else like top speed and civilised appearance has lower priority, I intend to convert my homemade steam engine to a wanking machine and set up a tent with a fair ticket price to get gas money and a few laughs...

[Johansson]

Today I made some final adjustments to the frame and welded it, it became very steady with no flex at all so it should prove a good high speed frame. The engine mounts will make it even stiffer so I am pretty satisfied with it.

M, what do you think of mounting the engine like this? A mount welded to the engine between the ejectors where the engines point of gravity is with a long slot milled for thermal expansion and two mounting brackets holding it. They can be made with adjustable lenght so I can tilt the engine up and down to find the best thrust angle.

[Eric]

I would put some triangulation facing forward reaching up to the same level, otherwise flexing of the long handle bar section could result in quite a bit of force on the engine mount which could bend or dent the engine.

[metiz]

you'd better wear some aluminium underwear if you're going to ride like that

[Johansson]

I would put some triangulation facing forward reaching up to the same level, otherwise flexing of the long handle bar section could result in quite a bit of force on the engine mount which could bend or dent the engine.

I forgot to mention that the thrust mount on the CC top is hinged so the rear of the engine is free to move up and down (if it weren´t for the rear mount), so even if the handle bars bend a bit it won´t damage the engine. The rear mount is not feeling any thrust at all, it only holds the engine level to the ground with a slightly loose fit so the engine can expand without deforming.

[milisavljevic]

Ahoy, Anders!

It became very steady with no flex at all so it should prove a good high speed frame.
The engine mounts will make it even stiffer so I am pretty satisfied with it.

Most excellent news, matey. An extra round of grog for ye troubles!

M., what do you think of mounting the engine like this?

Listen closely matey, ye very life be depending on it:. No attachments to the engine, please!

Thunderchine already be having a most sturdy frame. Any an' all attachments to ye kick must be made
to the frame, and the frame only. Thunderchine has a thrust mount and that be the only loaded mount.

If ye need be elevating the tail of the wee beastie, ye be using that frame. That be what a frame is for.

Aaarrr!!

Cap'n M.

[Johansson]

Eric and M, that crude frame I made for the engine was just for the initial testing, I never intended to use it to mount the engine to the kick. I can see now that from the pics I´ve posted it looks like I was going to use it, I should have explained that better.

So what you are saying is that the engine must be suspended in the CC thrust mount and the two bolts welded to the exit cone and nowhere else? That can prove to be a problem since the entire engine has to be suspended from the kick frame in front of the driver, if I fit anything to the runners I won´t be able to steer any more...

[milisavljevic]

Avast!

That crude frame. [snip...]. I never intended to use it to mount the engine to the kick.

I should have explained that better.

Ye be making the understatement of the year there, matey. Me blood be boiling with the furies now!

The entire engine has to be suspended from the kick frame in front of the driver.

Hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahaha!

Matey, did ye say "The entire engine has to be suspended from the kick frame in front of the driver"?

Hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahaha!

Oh, wait...ye be serious?

Hahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahahaha!

Ye be a riot, matey. I give ye that. More fun than a feast of stale biscuits an' weevils in a rolling sea.
Let me think on it a time, matey. I have one idea, but me blood is all burning rage and needs to cool.

I will return to these shores soon enough, carrying me solution or me cutlass. I canna say which one.

Aaarrr!!

Cap'n M.

PS: Why not ye give Thunderchine runners? A wee pair, below the super cone. "Independent suspension!"

What say ye, icelubber?

[Eric]

Piracy aside, if you are worried about the midsection why not have a cradle setup underneath that supports the midsections weight, rather than having something that rigidly mounts to it?

Could have an arm welded from the front mount down underneath the engine that cradles it, but isn't attached in any way at the middle.

[Johansson]

PS: Why not ye give Thunderchine runners? A wee pair, below the super cone. "Independent suspension!"

That might prove to be a bumpy ride for the engine since the ice won´t be perfectly flat, and having a glowing hot steel tube bouncing up and down between my legs is not exactly my idea of having fun...

if you are worried about the midsection why not have a cradle setup underneath that supports the midsections weight, rather than having something that rigidly mounts to it?

Shouldn´t a rear mount fitted to the engine at the balance point (like in my drawing) produce the least amount of stress? If the engine is only suspended at the ends it feels like the weight of the engine could make it bend at the tail coupler when it is hot and is run down an uneven track.

[milisavljevic]

Ahoy, Anders!

I give ye me blessing to drop ye mounts off the kick frame on down to Thunderchine's tailpipe.

However, there be some modifications to ye proposed plan of attack. Here they be in list form:

[1] Lay ye down a steel mounting rail atop the super cone, then ye weld it fast;
[2] The rail be all of 140 mm long and reaches yon splitter on its forward edge;
[3] Ye anchor point is dead center this mounting rail, weld ye slotted eye there;
[4] Drop ye mounting arms down from ye kick frame an' capture ye slotted eye.

If ye be using angle iron ("L" or "U") for ye mounting rail, then ye whole mount is but one piece,
as ye can slot the side(s) of the rail not welded to the super cone. Cap'n M. likes this simplicity.

If Cap'n M. has to land these shores again, he's bringin' his cutlass an' will surely run ye through.

Aaarrr!!

Cap'n M.

PS: If ye be confused, make a sketch of what ye thinks [1-4] means and post it here for review.

[Johansson]

Sounds like a good plan there, cap´n. I´ll get right to it!

[milisavljevic]

Hejsan Anders!

Cap'n M. drank all my rum while watching this movie on DVD, then passed out on the fo'c'sle ( peace at last! ).

Sounds like a good plan there, cap´n. I´ll get right to it!

To the maximum extent possible, weld the 140 mm mounting rail continuously along its length to the super cone.
A longer rail is a better rail; if you use a longer rail, keep your anchor point in the same place as described before.

Cheers,
M.

[Eric]

[quote="milisavljevic"

Sounds like a good plan there, cap´n. I´ll get right to it!

To the maximum extent possible, weld the 140 mm mounting rail continuously along its length to the super cone.
A longer rail is a better rail; if you use a longer rail, keep your anchor point in the same place as described before.

Cheers,
M.[/quote]

Welding anything solid on an engine, along the solids entire length is very very bad and will destroy your engine in a few runs or less!

Longer is also most certainly not better for something like this! A 8" bar welded flat against 20 gauge stainless at two ends will result in enough expansion force to stretch the bar until it bows .6" away from the sheet once cooled.

The thermal expansion generates many many thousands of pounds of expansion force.

If a solid object is welded to the sheet, it will stay relatively cool compared to the sheet, so the net result will be a stretching of the solid object to match the sheets length.

When things cool down the rail will curve as if the sheet were a tightly pulled string on a bow, warping the sheet, causing lots of stress along the seam, and within 1-3 thermal cycles it will crack along the entire length, or shear off entirely.

Welding the rail at each end will not eliminate the bowing, but the rail will be able to warp independently of the sheet and only generate an insignificant amount of stress at the ends.

This is why its important to use a cradle type setup for many reasons, and only have one hard mounting point.

If you absolutely feel you have to weld a mount on, the best way to do it is to use a V shape bent bar, with the mounting arm connected at the point of the V. Expansion generated between the tips of the V will be easily absorbed by the V bars flexibility, and not produce any great deal of stress on the engine.

Eric

[milisavljevic]

Anders,

There was some static on the line earlier; I hope that this did not disturb your work.
Please proceed as was discussed. If you cannot do this, then ignore what I post here.

Cheers,
M.