Author Topic: 1/3rd scale V10  (Read 226299 times)

Offline keith5700

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Re: 1/3rd scale V10
« Reply #120 on: February 18, 2015, 07:54:06 AM »
Jayykt, the turbo looks interesting and its exactly the sort of thing I had in mind when I started the V10.
It has become clear however that at the size I wanted them to be, they wouldn't work very well, ie. produce any useful boost.
I can't find much else about that heli turbo, but can only assume it's just for show.
Cheers.

Offline Brendon M

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Re: 1/3rd scale V10
« Reply #121 on: February 18, 2015, 12:51:25 PM »
Your V10 will displace around 125cc, if I remember correctly. Being multi-cylinder, will that be able to drive a really small turbocharger intended for motorbikes? (as if you a mounting a big single for a full-sized engine)

http://www.cbr250.net/forum/honda-cbr250-general-discussion/8213-turbo.html

Hitachi HT06, fits in your hand
https://www.google.com.au/search?q=hitachi+ht06+turbo&source=lnms&tbm=isch&sa=X&ei=6YnkVJWnDsa2mwWkhoKQAg&ved=0CAgQ_AUoAQ&biw=1596&bih=781

Yamaha Turbo
http://www.realhomemadeturbo.com/forum/index.php?topic=1661.0
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Offline keith5700

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Re: 1/3rd scale V10
« Reply #122 on: February 18, 2015, 04:19:10 PM »
Hi, yes 125cc, I reckon I could have done something with that, but unfortunately I like things to be symmetrical, which means 2 turbos, so its only 62cc per turbo, which isn't really enough it seems.
I'm too far down the line with the supercharger now anyway, but turbos was my first choice.

Offline MrDude_1

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Re: 1/3rd scale V10
« Reply #123 on: March 25, 2015, 01:31:46 PM »
Hi, yes 125cc, I reckon I could have done something with that, but unfortunately I like things to be symmetrical, which means 2 turbos, so its only 62cc per turbo, which isn't really enough it seems.
I'm too far down the line with the supercharger now anyway, but turbos was my first choice.

Actually, we put turbos on 50cc minibikes... so you COULD use the same commercial turbos on your 62cc per side.  There is a slight amount of turbo lag, but since you're not running this around a racetrack, I dont think that would be a big issue.
I think the biggest issue is they wont look as amazing as the rest of your engine... they're ugly cast things, with the only machine work done on surfaces you cant see from outside.

Online mike mott

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Re: 1/3rd scale V10
« Reply #124 on: March 26, 2015, 04:32:24 PM »
Keith I am enjoying your engine build and since I also do all my work manually I am particularly impressed by your workmanship and finishing skills.

Mike
If you can imagine it you can build it

Offline keith5700

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Re: 1/3rd scale V10
« Reply #125 on: March 30, 2015, 12:44:46 PM »
Right, progress report:-

I decided to try some G. Britnell style profile milling, just to pretty things up. Took absolutely ages to do both sides of the crankcase.








Offline keith5700

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Re: 1/3rd scale V10
« Reply #126 on: March 30, 2015, 01:01:46 PM »
Had a go at the driveshaft for the supercharger. The drive needs to be at the rear of the engine, and up to the s/c with another belt.
The supercharger will be built in to the rear of the intake plenum.

The s/c needs a 2.6:1 speed increase over engine rpm, according to my crude calcs. I was a bit concerned about the strain on the drive system when revving the engine up fast, due to the inertia of the s/c rotors and gears, so I have put a slipping clutch into the rear timing pulley. The clutch discs are ptfe.

I wanted the preload on the clutch pack to be via a Bellville conical washer, but couldn't find anywhere to buy less than 25's worth min. order, so I decided to make one.

I used some nice spring steel strip, which are actually Almen strips we use at work to measure shot peening intensity.
These were softened, drilled, turned, pressed into a cone, hardened back up, and then tempered a bit from light straw colour.
It works fine.















Offline ozzie46

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Re: 1/3rd scale V10
« Reply #127 on: March 30, 2015, 01:12:10 PM »
No words,just  :pinkelephant: :pinkelephant: :pinkelephant:

 Ron

Offline DavidF

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Re: 1/3rd scale V10
« Reply #128 on: March 30, 2015, 03:02:43 PM »
Keith, Thats looking great!!  How long until you give the plans away to the chineese??  :lolb:
<---Mr sarcasm

Online Art K

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Re: 1/3rd scale V10
« Reply #129 on: March 30, 2015, 05:50:27 PM »
Keith,
I must say like everyone else that I am amazed by your creativity and craftsmanship, wow.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Tennessee Whiskey

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Re: 1/3rd scale V10
« Reply #130 on: March 30, 2015, 06:51:27 PM »
First of all,  great work.  Secondly,  you mentioned shot peening,  is that the way you are reproducing the cast effects?  IMHO guys like you and Britnell are just in a totally different world,  one that I admire greatly  :ThumbsUp: :ThumbsUp:

Cletus

Offline keith5700

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Re: 1/3rd scale V10
« Reply #131 on: March 30, 2015, 10:37:58 PM »
Thanks for positive replies, it urges me on to get better all the time.

Cletus, we have all sorts of surface treatments available at work, but most could also be done at home.
The lugs on the crankcase have been shot peened with 110 size steel shot. This will be the final finish for the large components as they are too big to get in my anodising bucket.

The supercharger bearing brackets have been peened with ceramic beads and then anodised and dunked into the black dye tank for about 10 seconds, and then heat sealed. This gives a nice blue tint.
The danger with anodising is its too easy to get carried away with all the colours and end up with a Xmas tree decoration. I'm trying to stick with shades of black and gold only on this engine.

David, i think I'll pass on that one, but it would be interesting to see how much they could make it for?
Cheers.


Offline billmac

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Re: 1/3rd scale V10
« Reply #132 on: March 31, 2015, 04:45:11 PM »
I think your concern about the supercharger drive is well justified. The slipping clutch is a good precaution, but there may be a limited window between slipping and delivering the normal running torque required at higher revs. There are other methods of easing problems with supercharger drives that you have probably already considered; one is to use a long drive shaft with a small diameter, but well supported. This allows for a small degree of torsional wind-up which reduces snatch loading on fast rev changes. Another is to use a sprag clutch so that the supercharger is free to rotate in the reverse direction. This insulates it from snatch loads in the throttle snap shut situation.

The other concern with the drive is what happens in the event of a backfire of course.

There was quite a lot of research on supercharger drives for (full sized!) aircraft engine development.


Offline billmac

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Re: 1/3rd scale V10
« Reply #133 on: March 31, 2015, 04:53:09 PM »
Another random thought on the supercharger drive which I forgot in my last message. Some engines suffer from torsional vibration problems because of their overall layout and the crankshaft length (long straight sixes for example). Firing order has an influence here of course. The torsional vibration can be started because the rotation of the crankshaft is not really uniform and torque is applied at points a long way down the crankshaft. This effect can be magnified through a shaft supercharger drive and become an added nuisance. Some carefully designed compliance in the drive can help. Some work on the layout of your V10 might predict whether this will be the case, but the fact that it is a small engine should limit the risk.

Offline keith5700

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Re: 1/3rd scale V10
« Reply #134 on: April 14, 2015, 01:06:07 PM »
Billmac, I think the clutch should be fine for this purpose. In my head I can see the difference in high speed running torque and acceleration torque to be a factor of 2 or 3 different, so hopefully there won't be any clutch slip during steady running.

I got bored with making sparkplugs, using my recently aquired Macor, (thanks again Ramon), so I decided to make a test rotor for the supercharger. The proper rotors will be 90mm long, but I just did a trial piece and cut it in half to try the mesh.
The centre distance is dictated by the already existing helical gears.













« Last Edit: April 14, 2015, 01:25:32 PM by keith5700 »