2STROKE STUFFING I know a guy that has a rig just like it ;) Probably also copied from NASA designs. A shout out seemed like the sensible thing to do, because otherwise I'd just be repeating all the things you already said. Your video on the subject is excellent for those wanting to know more and I felt the internet didn't need another one :)
How are they ever going to replace it! It will take decades of research to rebuild it. NASA, if you're reading this, I'm willing to part with mine for a billion dollars. Don't bother trying to steal it from me, I have hidden it at the most secure of locations: my garage. It's so secure that even tools that you held 20 seconds ago cannot be found.
Genius edit ...had to be ....? Can you drill holes near the conrod pin each side deep then shallow to balance without adding any extra weight ? Also I remember good engine and exhaust rubber mounts really changed the ride once upon a time .
Nice holes! I'm excited to hear if you can feel the difference. I wonder what the crankshaft manufacturers have in mind when they design crankshafts, the "full round and stuffed" versions. A Puch moped engine is originally around 37%. A tuning crankshaft can be as low as 19% with the stock piston, and 16% with a big bore piston :-( But somehow, i don't remember that the engines i've build with a low balance factor like this, had any bad vibrations?
Carsten Lorenzen I've checked a couple of Puch cranks too and they were also around 20-ish with the stock piston. I've never had problems with vibrations on them either, maybe the whole assembly is just too light to cause any damage. I think my vibrations are mostly caused by some kind of resonance, if you look at the test ride video where I'm lifting the back off the stand you can see the carb moving several cm up and down. And the day after things fell off because of the bad vibrations at low rpm. I got the adapter plate welded onto the case today so it's all good to be bolted back together now, we'll see this weekend if it reduced vibrations or not :)
If my crankshaft in a calm state looks not at 12:00 but at 14:00. Where to drill a hole for inserts. I plan to install an enlarged piston + 20g on the Yamaha BWS50
Russ White Thanks! I'm hoping that after this it will actually stay together for longer than half an hour so I can get some tuning done. There's plenty of work to be done on it still, but I just want to go and see how it runs now with hopefully most of the bugs worked out. I'm already planning next winters update, if it works like I hope it will it's going to need a better chassis than a 69 Oly so I'm thinking of what to do about that.
AuMechanic Mine is a ZX7045 with some upgrades (power X feed and DRO). It's awesome for drilling but I hope to get my big mill into the shop this summer, because this one is not the sturdiest machine for milling. Although I usually make things work anyway, just gotta take it easy, small cuts. I think I'm about 50/50 on the mill/drill and lathe.
Same mill as mine, sold as a different brand here in Aus I've had mine since 2005, use it in my business full time and it still going, not bad for made in China. Not engine stuff. I didn't add a DRO, handy for doing batches, but for single jobs its wasn't worth the cost for me likewise the feed, for larger batches of parts like 5 or more I used to send the file to the CNC guy to do a box while I got to other jobs. I find so long as I keep the slides and quill clamped up a bit for the cut it doesn't get too slack.
Mine is also from 2005 or 2006 I think. And other than the big seal leaking very slightly it's also still going strong. The one thing that annoys me about it is the lack of a spindle lock, have you added one on yours? I actually did all of the machine work for the stroker crank with it. But that was quite an adventure, and I had to redo it 3 times. Really got to know it a whole lot better when accuracy was more critical than any of the other stuff I've done with it. But the DRO really helped there, I use it for everything really. Locating, bolt patterns, being able to go back and forward between holes/coordinates in a hurry. I bought the machine used from a local fab shop and the auto feed and DRO were already on it.
I put the gearbox into lowest speed to undo collets and the taper centre bolt. Got mine new for about 3600 AUD. There is a slight leak on the main seal that drips on to my knuckles now and then undoing jaws or collets but the sight glass is still near the mark. My main annoyance has always been the vertical gear lash and having to keep it semi clamped to avoid it dropping down when doing a milling job.
Mine has actually started doing that too, fairly recently. The dropping thing. It never used to do that before, or maybe I just haven't noticed. Same here with the oil, lots of drops have come out but the level never seems to go down. I put it in the lowest gear too but it kind of feels like I'm abusing the gearbox that way.
When your balancing, dont you need to simulate the piston weight on the end of the crank in order to get the correct weight that needs to be changed? I think your crank is going to be heavily piston side biased now.
The piston and pin are part of the equation too yes. But the goal with balancing a 2-stroke is not to get an equal weight on both sides, but to get a reasonable balance factor. A single cylinder is never going to be balanced at all rpms so basically you're just trying to move the bad vibrations to an rpm where they don't do any harm, eg to an rpm below idle speed. On my engine the worst vibrations were exactly in my idle range, raising the balance factor moved the vibrations down to a lower rpm range where they don't really matter. I recommend that you check out 2stroke stuffings video on the crank balancing, he explains it very well :)
@@Hollaendaren Great content. May I ask how do you shift the vibrations (or the frequency) toward a certain revs range? Has it got to do, with the radial position of the holes, nearer or farter from the crankpin or what? Thanks
@@robertomalatesta6604 I'm not sure if there is a general formula, from what I'm reading it seems it is pretty much trial and error. In my case I knew that a stock crank assembly with stock piston had a higher balance factor than my stroker crank, and it also had the vibrations at a lower rpm. So it seemed like a higher balance factor should lower the vibration rpm on my engine so that's the direction I went. As it turns out it did exactly that, vibrations are well below idle speed now :) but this "formula" most likely only works up to a certain point, maybe if the balance factor is too high the vibration rpm would go up again. I think this will be different for every engine depending on cylinder angle, engine mounts etc. I'm happy with the way it runs now so I probably won't change it any more.
Does hanging the connecting rod straight down instead of the piston end in a position inline with the crank (normal operating position) affect the counterbalance weight needed?
Devin good question! I hadn't given that any thought but I don't think it makes any difference. It's still going to weigh the same and hang off the same position. I could be wrong there though, I'm not a physicist ;) But it would be hard (if not impossible) to tell if it's balanced or not if you have to push against the top of the rod to keep it centered, the crank would start rolling because of that so that kind of defeats the whole setup.
My thinking is, for example, that at 90 degrees from tdc the rod hanging straight down would have more centrifugal force because of the entire rod weight at that distance from the center of the crank verses if the piston end was inline with the crank, the rod would be at an angle and the weight of the rod at the crank end would effectively be less. Therefore, I would think less counterbalance weight would be necessary to balance the crank.
I think you're going beyond the concept of balance factors now and getting more into dynamic balancing territory. The percentage balance factors only take mass into account afaik, not forces acting upon that mass. I once got a quote to get a 3 cylinder crank dynamically balanced, they needed to know the same kind of info as well as an rpm range. I don't remember the exact price but it was going to cost me somewhere in the order of $2-3k for that crank, I opted out ;)
jnuxca I wasn't really gone ;) I've been in the garage almost every day since the last video except when I was sick, and I've been shooting videos but no time to edit :/ I have about 250 GB of footage of the TNT build but haven't even started editing so that'll take a while if it ever gets done.
The problem is that I got a new camera and most of the TNT footage is kind of shit (flickering, some also blurry) because I used the wrong settings. Problem 2 with it is that I don't have an ending for it yet because I was so stressed on the last build day that I literally forgot to film anything that day. And on race day my Gopro didn't work because the battery died before I even turned it on, because of the cold :/ So I'm trying to figure out how I'm going to salvage all of this before I start editing all that footage :)
Especially missing the race footage sucks, kind of an anticlimax :( I actually brought my powerbank with me so I could charge the battery if needed (on top of it being fully charged the day before), but I brought the wrong charger cable... But not much I can do about it now. But the good news is that I broke some stuff at the race, so I'm going to have to work on it a bit more. I want to get it fully done and ready for racing before the end of the winter (at least a couple weeks left here, we still have about a meter of snow) so there's still hope for a better ending :)
DrBOB101 Secret! ;) I probably should have mentioned that, or better said not have cut out the bit where I mentioned it.. It's to hopefully get rid of the heavy vibrations I've been having at idle speed which were causing bits to fall off the engine.
It's easy to forget that maybe not everything is self explanatory when I've been thinking about it for months myself ;) Added the reason to the video description now at least.
the crank volume isnt that important in my expierience, when the exhaust system is well "sucking".... when that isnt the case the transfering pressure gets more important... but as i saw your pipe i think it would mostly fit in the first case, so you probably dont have to worry about big powerloss^^
I'm not worried about crankcase volume, the more the better! I added a 19mm spacer remember ;) But maybe the holes cause some kind of weird turbulence, although I can't really imagine there'd be a noticable power loss. But manufacturers stuff their cranks even today, probably for a reason but I don't know why.
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Love the balancing jig! Thanks for the shoutout!
2STROKE STUFFING I know a guy that has a rig just like it ;) Probably also copied from NASA designs.
A shout out seemed like the sensible thing to do, because otherwise I'd just be repeating all the things you already said. Your video on the subject is excellent for those wanting to know more and I felt the internet didn't need another one :)
Hollaendaren Thanks! Yep, well mine was actually stolen from NASA.
How are they ever going to replace it! It will take decades of research to rebuild it.
NASA, if you're reading this, I'm willing to part with mine for a billion dollars. Don't bother trying to steal it from me, I have hidden it at the most secure of locations: my garage. It's so secure that even tools that you held 20 seconds ago cannot be found.
@@2STROKESTUFFING I got a 2 stroke stuffing vibe the moment the video began playing !!!!! Strange ??!!!!
First time watching a video of yours, I noticed a Harley SX head on your bench. I am working on balancing the crankshaft of mine now.
Genius edit ...had to be ....? Can you drill holes near the conrod pin each side deep then shallow to balance without adding any extra weight ? Also I remember good engine and exhaust rubber mounts really changed the ride once upon a time .
Really good video, love the editing. The only downside is that it is getting harder to drink coffee while you watch.
Haha, thanks! :)
Nice holes! I'm excited to hear if you can feel the difference. I wonder what the crankshaft manufacturers have in mind when they design crankshafts, the "full round and stuffed" versions. A Puch moped engine is originally around 37%. A tuning crankshaft can be as low as 19% with the stock piston, and 16% with a big bore piston :-(
But somehow, i don't remember that the engines i've build with a low balance factor like this, had any bad vibrations?
Carsten Lorenzen I've checked a couple of Puch cranks too and they were also around 20-ish with the stock piston. I've never had problems with vibrations on them either, maybe the whole assembly is just too light to cause any damage. I think my vibrations are mostly caused by some kind of resonance, if you look at the test ride video where I'm lifting the back off the stand you can see the carb moving several cm up and down. And the day after things fell off because of the bad vibrations at low rpm.
I got the adapter plate welded onto the case today so it's all good to be bolted back together now, we'll see this weekend if it reduced vibrations or not :)
If my crankshaft in a calm state looks not at 12:00 but at 14:00. Where to drill a hole for inserts. I plan to install an enlarged piston + 20g on the Yamaha BWS50
Man your videos are just the best great viewing thanks much do it again i double dare you! And yes i know racers cant resist a good dare! Atb Russ
Russ White Thanks! I'm hoping that after this it will actually stay together for longer than half an hour so I can get some tuning done. There's plenty of work to be done on it still, but I just want to go and see how it runs now with hopefully most of the bugs worked out. I'm already planning next winters update, if it works like I hope it will it's going to need a better chassis than a 69 Oly so I'm thinking of what to do about that.
goob morning my friend...can you help me find the weighing of my crank and what holes will i make?? do you have an accound fb?
Learning every day me 💯💯 awesome video
Please tell me how number of percentage of this balance factor ? because my english is not too good. Like from indonesian.. Thanks
crank w holes, what would it looked like when you place the actual piston kit on a balanced crank? would it also stops at every position?
sir how did you get the balance factor of 31.4 grams?
Your mill drill looks very similar to mine.
My most used machine.
AuMechanic Mine is a ZX7045 with some upgrades (power X feed and DRO). It's awesome for drilling but I hope to get my big mill into the shop this summer, because this one is not the sturdiest machine for milling. Although I usually make things work anyway, just gotta take it easy, small cuts. I think I'm about 50/50 on the mill/drill and lathe.
Same mill as mine, sold as a different brand here in Aus
I've had mine since 2005, use it in my business full time and it still going, not bad for made in China.
Not engine stuff.
I didn't add a DRO, handy for doing batches, but for single jobs its wasn't worth the cost for me likewise the feed, for larger batches of parts like 5 or more I used to send the file to the CNC guy to do a box while I got to other jobs.
I find so long as I keep the slides and quill clamped up a bit for the cut it doesn't get too slack.
Mine is also from 2005 or 2006 I think. And other than the big seal leaking very slightly it's also still going strong.
The one thing that annoys me about it is the lack of a spindle lock, have you added one on yours?
I actually did all of the machine work for the stroker crank with it. But that was quite an adventure, and I had to redo it 3 times. Really got to know it a whole lot better when accuracy was more critical than any of the other stuff I've done with it. But the DRO really helped there, I use it for everything really. Locating, bolt patterns, being able to go back and forward between holes/coordinates in a hurry.
I bought the machine used from a local fab shop and the auto feed and DRO were already on it.
I put the gearbox into lowest speed to undo collets and the taper centre bolt.
Got mine new for about 3600 AUD.
There is a slight leak on the main seal that drips on to my knuckles now and then undoing jaws or collets but the sight glass is still near the mark.
My main annoyance has always been the vertical gear lash and having to keep it semi clamped to avoid it dropping down when doing a milling job.
Mine has actually started doing that too, fairly recently. The dropping thing. It never used to do that before, or maybe I just haven't noticed.
Same here with the oil, lots of drops have come out but the level never seems to go down.
I put it in the lowest gear too but it kind of feels like I'm abusing the gearbox that way.
Can you tell me where I can get a new crank for a rotax 277?
When your balancing, dont you need to simulate the piston weight on the end of the crank in order to get the correct weight that needs to be changed? I think your crank is going to be heavily piston side biased now.
The piston and pin are part of the equation too yes. But the goal with balancing a 2-stroke is not to get an equal weight on both sides, but to get a reasonable balance factor. A single cylinder is never going to be balanced at all rpms so basically you're just trying to move the bad vibrations to an rpm where they don't do any harm, eg to an rpm below idle speed. On my engine the worst vibrations were exactly in my idle range, raising the balance factor moved the vibrations down to a lower rpm range where they don't really matter.
I recommend that you check out 2stroke stuffings video on the crank balancing, he explains it very well :)
@@Hollaendaren Great content. May I ask how do you shift the vibrations (or the frequency) toward a certain revs range? Has it got to do, with the radial position of the holes, nearer or farter from the crankpin or what? Thanks
@@robertomalatesta6604 I'm not sure if there is a general formula, from what I'm reading it seems it is pretty much trial and error. In my case I knew that a stock crank assembly with stock piston had a higher balance factor than my stroker crank, and it also had the vibrations at a lower rpm. So it seemed like a higher balance factor should lower the vibration rpm on my engine so that's the direction I went. As it turns out it did exactly that, vibrations are well below idle speed now :) but this "formula" most likely only works up to a certain point, maybe if the balance factor is too high the vibration rpm would go up again. I think this will be different for every engine depending on cylinder angle, engine mounts etc. I'm happy with the way it runs now so I probably won't change it any more.
Does hanging the connecting rod straight down instead of the piston end in a position inline with the crank (normal operating position) affect the counterbalance weight needed?
Devin good question! I hadn't given that any thought but I don't think it makes any difference. It's still going to weigh the same and hang off the same position. I could be wrong there though, I'm not a physicist ;)
But it would be hard (if not impossible) to tell if it's balanced or not if you have to push against the top of the rod to keep it centered, the crank would start rolling because of that so that kind of defeats the whole setup.
My thinking is, for example, that at 90 degrees from tdc the rod hanging straight down would have more centrifugal force because of the entire rod weight at that distance from the center of the crank verses if the piston end was inline with the crank, the rod would be at an angle and the weight of the rod at the crank end would effectively be less. Therefore, I would think less counterbalance weight would be necessary to balance the crank.
I think you're going beyond the concept of balance factors now and getting more into dynamic balancing territory. The percentage balance factors only take mass into account afaik, not forces acting upon that mass.
I once got a quote to get a 3 cylinder crank dynamically balanced, they needed to know the same kind of info as well as an rpm range. I don't remember the exact price but it was going to cost me somewhere in the order of $2-3k for that crank, I opted out ;)
Hello there mate, can we true a 4 stroke crank? If yes then how? Any links, please
I have no idea to be honest.
welcome back : D
jnuxca I wasn't really gone ;) I've been in the garage almost every day since the last video except when I was sick, and I've been shooting videos but no time to edit :/ I have about 250 GB of footage of the TNT build but haven't even started editing so that'll take a while if it ever gets done.
250gb hell yeah, we'll be waiting ahahah
The problem is that I got a new camera and most of the TNT footage is kind of shit (flickering, some also blurry) because I used the wrong settings. Problem 2 with it is that I don't have an ending for it yet because I was so stressed on the last build day that I literally forgot to film anything that day. And on race day my Gopro didn't work because the battery died before I even turned it on, because of the cold :/ So I'm trying to figure out how I'm going to salvage all of this before I start editing all that footage :)
that's a bummer :/
Especially missing the race footage sucks, kind of an anticlimax :( I actually brought my powerbank with me so I could charge the battery if needed (on top of it being fully charged the day before), but I brought the wrong charger cable... But not much I can do about it now.
But the good news is that I broke some stuff at the race, so I'm going to have to work on it a bit more. I want to get it fully done and ready for racing before the end of the winter (at least a couple weeks left here, we still have about a meter of snow) so there's still hope for a better ending :)
And what exactly is the use balancing everything out by drilling the holes?
DrBOB101 Secret! ;) I probably should have mentioned that, or better said not have cut out the bit where I mentioned it.. It's to hopefully get rid of the heavy vibrations I've been having at idle speed which were causing bits to fall off the engine.
That clarifies for the engine noobs under us
It's easy to forget that maybe not everything is self explanatory when I've been thinking about it for months myself ;) Added the reason to the video description now at least.
Make it like that without the cost ... ??
How about keep the vacuum going while drilling ? :)
I should probably fabricate some kind of holder for the vacuum nozzle :)
coat hanger :)
Very billion.
the crank volume isnt that important in my expierience, when the exhaust system is well "sucking".... when that isnt the case the transfering pressure gets more important... but as i saw your pipe i think it would mostly fit in the first case, so you probably dont have to worry about big powerloss^^
I'm not worried about crankcase volume, the more the better! I added a 19mm spacer remember ;) But maybe the holes cause some kind of weird turbulence, although I can't really imagine there'd be a noticable power loss. But manufacturers stuff their cranks even today, probably for a reason but I don't know why.
yea! ..you could be right ..think i ve seen something like this in a NASA facility before
I knew it! I must have seen it on some space documentary. ;)
what's a mangold ?
www.urbandictionary.com/define.php?term=man+cold
Interested ur content
du får börja hyra ut balansmaskinen (plankorna)😂
Ja jag kommer ju bli rik! ;)
You sir have not a clue at figuring the weight of a bob weight. You most likely don't even know what a bob weight is.