High torque clutch?

[smooth90]

I posted a while back about what clutch I should get for an Onon p220g engine.

I went with a Noram 1600 series #40 chain centrifugal clutch rated for 15hp. My engine is 20hp but I figured that with the large amount of prior use its probably putting out a bit less 18 maybe. It is "overpowered" for the clutch but not by much so I assumed just a shorter lifespan.

Anyway.......

I got a large 2 seater SunL go kart frame with no engine for a hundred bucks. It was in good shape and all the tires were still good the front tires are like 14 - 16in and the back tires are 22x10 tires which are pretty big. I heavily modified it and welded in a frame to support the engine as well as all supporting hardware (chain, jackshafts, sprockets).

Today me and my friend assembled the whole go kart for its first test drive. It started off a bit slow but as soon as it hit about 10mph it was like I was in a rocket ship that thing took off!

Here's where it gets bad.....

I wanted to see some off road performance so I drove it around my small lawn (with a fairly small hill). When I tried to go back up the hill (at about 3 - 5 mph starting) the cart started heavily smoking out of the clutch.

The clutch pads look like that got about 20 percent burned up so the clutch is far from dead. It was very hot and discolored (in a perfect ring) around where the pads engage.


______________________________________________

SPECS

ENGINE 20hp

Max rated RPM 3600

(Estimated max rpm 5000 - 6000)

Idle speed 1000rpm

Clutch

2000 rpm engagement

GEARING

Engine input -----30T Sprocket (Drives Jackshaft 1)

Jackshaft 1

25T Sprocket -------Clutch 14T (Drives Jackshaft 2)

Jackshaft 2

30T Sprocket--------12T Sprocket (drives sprocket on axle)

Axle

36T Sprocket


This ratio is setup to do about 45 mph at 4000rpm or so. I don't remember the specifics when I calculated the ratios but that is really the top speed I wanted.

So I'm really looking for some sort of clutch system (does not matter what) that can handle this massive torque load.

Picture

 

[jrmints1415]

torque converter or cvt will not burn out and give you more torque to take it off road. They cost like 200 bucks but there worth every penny!!

 

[Doc Sprocket]

Shop for a Comet 40 or equivalent. That'll put up with the abuse. As a matter of curiosity, why did you choose to put the clutch on a jackshaft, thereby altering the engagement speed, rather than mounting it to the engine directly?

 

[smooth90]

I had to put the clutch on a jackshaft because it will not fit on the engine shaft.

I don't know why but the engine has a 1 7/16 in shaft with a 3/8 (or 5/16) keyway. The clutch has a 1in bore so its almost half an inch too small.

I will have to look into the torque converters....bit expensive but I may need it.

 

[anderkart]

Sounds like a torque converter would be your best option to achieve good climbing ability and a 45mph top speed. But swapping out one of your jackshaft gears to achieve a 25mph top speed would give you much better climbing ability and help keep your current clutch from overheating.

The Noram Enforcer clutch I recommended in your other thread would handle more HP and abuse than the 1600 series you have now, but if your going to spend that much you should probably just go with a 40-series converter.

 

[vpd66]

The reason why that engine has that size output shaft is because it was designed for a garden tractor that mounts an electric clutch on it. Thats an expensive engine when looking for one used and parts are very high priced for that engine. If it were me I'd sell that engine to someone that needs one for a garden tractor. They will pay good money for it if it runs good. I'd then take your profit and look for a used motorcycle or atv and use that motor with the built in transmission.

 

[porsche930dude]

wow thats the craziest jackshaft setup iv ever seen! I would lower the gearing some if yor ok with loosing some top speed. you must have spent alot on that setup already. Youll have to redesign the whole thing to get a torque converter on there. like everyone else suggests maby find an old 3 wheeler with an auto tranny they can be had pretty cheap usually less than a 40 series

 

[smooth90]

Thanks for the replies!

The jackshaft system has to stay regardless because of the wheel size. Most of the karts I've seen are 16in wheels or less, much less for fast street driving.

Geometry 101, the circumference of a circle is 2*3.14*radius so as the tire gets bigger the travel per revolution gets longer. These tires have an 11in radius or 22in diameter, that means that per revolution it travels about 70 linear inches or 5.8ft.

So 45mph tops would equate to 3960ft per minute.....at 5.8ft per revolution that is an rpm of about 685 rpm on the axle.

I assumed the engine would hit 4000rpm during good usage (not a red line but still powerful) so that's the rpm I wanted the 45mph speed at. With that I needed a reduction ratio of right around 6:1. Right now its around 5:1 as I couldn't get a bigger reduction with the current clutch engagement so top speed of about 52mph.


___________________________________


Anyway I think I've found a solution to the clutch problem that will cost about $20 (I've got most of the stuff on hand).

See this post

http://www.diygokarts.com/vb/showthread.php?t=4956

I think that the concept there is solid it just needs some muscle and precision to make it work. The muscle will be in the form of a short - large bore pneumatic piston putting out a crap ton of force 500 - 2000lbs rather than a foot pedal. The precision will come from my CNC router cutting out thick aluminum parts and my TIG welder.

You can see my router cutting mdf at the bottom of the post.

It is no bridgeport but with lots of shallow passes (.01 - .02in) I have cut 5/8in thick aluminum plate on this.

So I can make all of the pivoting parts, the linkages, and the part that spins with the clutch precisely out of 1/4in to 5/8in aluminum. The only parts I need are the large bore piston (ebay) and the thrust bearing.

I've got a tremendous amount of pneumatic parts including a 5 way solenoid valve on hand so engaging this thing will be as simple as pushing a button.

I'm going to draw up plans later tonight I have to open the clutch up and measure some stuff.

https://www.youtube.com/watch?v=vCKq6dWgWRQ

 

[Bluethunder3320]

5:1 gearing is waaay too much for that.. with a centrifugal clutch the most youre going to get away with on that is probably 10:1.

a torque converter would help because you can gear it to (probably) 10:1 or 9:1, and the TC starts off in an even lower ratio than that. once you accelerate and the load eases off the engine, the TC keeps the load on the engine by shifting into higher ratios automatically getting the most out of the engine.

in better words,
instead of being stuck in "first gear" the torque converter keeps using the engines power to torque when you need it, and speed when you dont.

 

[smooth90]

I fully understand how a torque converter works but my opinion is that its a waste of money when you start looking at the 40 series. Your basic torque converter that's good for up to 8hp isn't bad for $200 and can be a big performance upgrade but the 40 series is $400 all said and done.

The torque/speed benefit is good but I still hate the idea that its not manual and is not selectable.

If I was going to dump the money for a 40 series I might as well spend another hundred and get a manual motorcycle transmission.

I have some new machine tools (thanks Santa).

 

[r_chez_08]

40 series = 2 or 3 norams in $

The durability of the 4 series would probably make it cheaper in the long run, and you also get a higher top speed and torque.

WIN!

 

[66 Shorty]

Thanks for the replies!

The jackshaft system has to stay regardless because of the wheel size. Most of the karts I've seen are 16in wheels or less, much less for fast street driving.

Geometry 101, the circumference of a circle is 2*3.14*radius so as the tire gets bigger the travel per revolution gets longer. These tires have an 11in radius or 22in diameter, that means that per revolution it travels about 70 linear inches or 5.8ft.

So 45mph tops would equate to 3960ft per minute.....at 5.8ft per revolution that is an rpm of about 685 rpm on the axle.

I assumed the engine would hit 4000rpm during good usage (not a red line but still powerful) so that's the rpm I wanted the 45mph speed at. With that I needed a reduction ratio of right around 6:1. Right now its around 5:1 as I couldn't get a bigger reduction with the current clutch engagement so top speed of about 52mph.


___________________________________


Anyway I think I've found a solution to the clutch problem that will cost about $20 (I've got most of the stuff on hand).

See this post

http://www.diygokarts.com/vb/showthread.php?t=4956

I think that the concept there is solid it just needs some muscle and precision to make it work. The muscle will be in the form of a short - large bore pneumatic piston putting out a crap ton of force 500 - 2000lbs rather than a foot pedal. The precision will come from my CNC router cutting out thick aluminum parts and my TIG welder.

You can see my router cutting mdf at the bottom of the post.

It is no bridgeport but with lots of shallow passes (.01 - .02in) I have cut 5/8in thick aluminum plate on this.

So I can make all of the pivoting parts, the linkages, and the part that spins with the clutch precisely out of 1/4in to 5/8in aluminum. The only parts I need are the large bore piston (ebay) and the thrust bearing.

I've got a tremendous amount of pneumatic parts including a 5 way solenoid valve on hand so engaging this thing will be as simple as pushing a button.

I'm going to draw up plans later tonight I have to open the clutch up and measure some stuff.

https://www.youtube.com/watch?v=vCKq6dWgWRQ

Nice Youtube Video series of the CNC Router! Did you build it yourself out of plans, or did you buy it that way? I've always been interested in having a CNC (seeing I program them everyday... LOL!) I have SO MANY ideas of things to make, but, I can use the ones here at the shop... Someone smashed a machine pretty badly & ruined it for anyone else that wants to use them now. :-(

 

[smooth90]

Its a Fireball V90 CNC router made by Probotix.

http://www.probotix.com/FireBall_v90_cnc_router_kit/

Watch the other videos and you will see the specs for my specific router. It is completely decked out and now it even has digitally variable speed....way too much time, effort, and money but well worth it in the long run.

Though that's not the only CNC I have as Santa was kind enough to bring me a Taig CNC mill this year! Can't wait to make some parts out of steel.

 

[66 Shorty]

I checked it out after I asked you the question... Cool Router table! I'd like something larger for a plasma torch & to be able to cut steel as a CNC Mill does. Can you do 3D surfaces on your router, or just 2D stuff? & it seems you can't do any metal on the router table, or have you done any aluminum?

There's NO WAY I'd be able to afford even the machine you have... LOL! I've seen some really nice ones people have made out of parts. Still lots of money & time invested to get them up & running, & I would only be doing it to make my own stuff. I don't see a large profit from making parts to sell...

 

[smooth90]

I'm only 17 at the moment so I've got minimalistic expenses and that's where I am able to buy these machines. So far I've added a Miller AC/DC Tig welder, CNC router, CNC mill, and a vast number of smaller tools like a compressor, drill press etc... Its taken me over 4 years to collect all of this stuff working at $8 an hour.

The way I see it is that in the future expenses will increase exponentially and I won't have money to buy tools. Right now I do have money so I'm buying quality American made tools. My goal is to have the fully equipped man cave capable (tool wise) of building anything I may come up with.



*******

As for the cnc router cutting aluminum it is possible to do this. The problem is that you have to take very light passes and things like chip clearance become a problem. For cutting out 2d aluminum plates (3/8" or less) it would work fine. I haven't tried 3d work but I would imagine you would have to take very light cuts.

Cutting steel is not impossible but is extremely risky because of the high rpm of the router. You will most likely eat through expensive bits like candy. I guess if you could run the router at 5000 rpm (like my router speed controller) and have constant coolant you could cut out some 2d plates with .005in passes.

The router simply does not have the gigantic bearing and heavy rigid column behind it that a milling machine has. The bit must take very light cuts and will have issue with surface finishes and precision. The thing I love about the router is the large build area 12x18in which is great for panels and large projects. The mill is fantastic for precision mechanical components.