Strange Frame
- Thread starter olChris
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olChris said:Al-otment said:
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That's hilarious.......stay out of the sun. Some people using forums don't seem to understand the concept - they are an area for public discussion. If you don't want opinions don't ask questions. I'm surprised you fail to understand the basic geometric principles advocated in"WSC" for checking alignment. Be sure to report how your bike handles when you get it on the road. I'm curious to what degree of hardening you are hoping to achieve with your blow torch and used engine oil on the swingarm spindle? It'll also require grinding after your 'heat treatment' - we're only talking £70 for new Andover Norton spindle and bushes which isn't much for a critical frame component. Good luck.
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Al-otment said:
Your right on that. Never seen any "Sealed for Life" components that ever lasted very long. The old Ford ball joints come to mind. I was surprised to read that my MKIII even had such a thing. It will be modified straight on to allow the ability to add oil...oh, and I knew that you add oil not grease...and strangely I found that information here...on this forum...but then I knew ahead of time bronze "Oilite" bushings should be oiled not greased from my industrial background and I also try to find the answers to questions I don't know or understand.
http://en.wikipedia.org/wiki/Oilite
concours
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Al-otment said:
OK, if you insist :mrgreen:
" the procedure is based on engineering fundamentals"
Engineering fundamentals includes tolerancing. NEEDLESS tightening of tolerances is all too common in todays manufacturing world, CAD pilot's unfamiliar with processes cause unwanted cost/effort to be put into the part. Overly precise tolerances don't make a better part, just a more expensive one. The point of diminishing returns.
"You need to re-read my post regarding machining to +/-0.0005", I was referring to the accuracy of a typical vertical milling machine in the xy parameters"
I repair vertical, horizontal machining centers daily. Turning centers as well. Ball screws, thrust bearings, etc. Spindle bearings set up within 2 microns, etc. If you're positioning within .0005" on your X and Y, then you're using flopped out old junk that is worse than what (I've read the folklore) was being used to make Norton bikes 40 years ago.
Not at all "wound up", just read this thread for days, and watched olChris do a great job saving a scabby old frame using FABRICATION (not toolmaker's) skills, as it should be, I felt the need to chime in and bring a few words of reality to keep people without fabricating/machining knowledge from spending another chunk of their retirement making the frame straighter than a laser beam. As you mention, this is a forum for discussion, which may sometime include viewpoints other than what one faction may hold to be THE UNWAVERING TRUTH. I wish you all the best with your frame services, I'm sure they'll work out well. Merry Christmas! :mrgreen:
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concours said:
I don't think that is what we are discussing. I've been working in the field of micro injection molding for the past several years on medical devices and we machine mold steel to ±0.00004" (Nano Precision) in precision machining centers with optical tool positioning, but I hardly see that applies here.
concours said:
With the tolerances we are talking about here .0005" is sufficient...even if done on an old Bridgeport the result would be adequate. The adjustments are positional for the most part and relocating holes does not require precision beyond a few thousants of an inch. Some could be done on a drill press with the right fixturing.
concours said:
While what olChris is doing is resourseful for sure, some of the technique and approach is questionable in terms of long term life and safety. The forum is here to share information, there are people reading here that may believe the methods olChris is using are appropriate, you for one. There may be others out there that given resources and knowledge may apply these appoaches, and quite frankly soft steel for the swing arm spindle creates a safety issue irregarless of home method of heat treatment, not to mention wear. Honing oilite bushings is a no-no and is called out in information previously provided. Poor methods may get the bike on the road cheaply but it doesn't make sense to substitute safety when a new spindle and bushings costs very little to replace.
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concours said:
With the majority of Commando owners reporting handling problems the accuracy I'm talking about is obviously necessary - road testing on my bike has proven the theory. No weaves, no reaction to grooves in the road, steers straight hands off etc etc.
concours said:
You're contradicting yourself. You imply close tolerances in this case are needless, then state a machine tool within 0.0005" is worn out and then imply a frame can be aligned to required tolerances using plumblines, fuzzy string and a rule. Using those tools and with the best will in the world accuracy will be no better than +/- 0.020". Never mind there's no fixed horizontal or vertical datum. That's a tolerance of upto 0.040" at best, which is in the region of the gaps I was measuring between the vertical datum and checking bar through the iso brackets. This tolerance was causing typical Commando handling problems which are normally associated with worn swingarm bushes. I fail to see your logic when you've mentioned previously that your bike's "feel" is compromised and is "scary at some speeds/conditions" and "blueprinting of the frame will not make those inherent design traits go away" yet you have not ridden a Commando with a blueprinted frame. The traits are not designed in, they are caused by the manufacturing process. Blueprinting i.e squaring axes, does cure the problems.
Thanks for your good wishes, but whilst the handling issues are believed to be design, rather than manufacturing problems, the un-enlightened will prefer the non-productive practice of bolting (expensive) bits on instead of accurate frame alignment.
concours
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" and quite frankly soft steel for the swing arm spindle creates a safety issue irregarless of home method of heat treatment, not to mention wear. Honing oilite bushings is a no-no and is called out in information previously provided. Poor methods may get the bike on the road cheaply but it doesn't make sense to substitute safety when a new spindle and bushings costs very little to replace."
olChris's choice to make his own spindle, oversize, from unknown (to us) material may not have been my choice to repair either, but, aside from accelerated wear and the need to refresh sooner, what is the safety issue you mention? Are you implying that it will bend/break catastrophically, disconnecting the swing arm and pitching the rider on his face? :?:
olChris's choice to make his own spindle, oversize, from unknown (to us) material may not have been my choice to repair either, but, aside from accelerated wear and the need to refresh sooner, what is the safety issue you mention? Are you implying that it will bend/break catastrophically, disconnecting the swing arm and pitching the rider on his face? :?:
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concours said:
It's a distinct possibility given the forces exerted on the components...particularly given the unknown material. A less severe result is more likely but could cause some other very dangerous results such as binding on one side and not the other. I wouldn't take a chance riding it and I pity the next owner if the bike makes it to the road. Sorry, that's my opinion. Concours, I get your position on his resoursefulness, and I applaud that but even if you don't believe in the blueprinting of frames, you have to agree that erring on the side of safety is more important than saving a couple of dollars. These parts are readily available and not that expensive. It would be much different and my opinion would be different if the only way to do it was to fab your own.
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Al-otment said:
Majority ? Do you have the survey results to hand ? The 'majority' of Commando owners based on my scientific research in pubs and bars will swear that their bikes out-handle anything apart from a Featherbed.
This talked about accuracy is all very well, but bearing in mind that engine plates and frame lugs are all bored with pretty generous clearance holes, I'm struggling to understand, unless the whole thing is re-engineered, just how the accuracy is maintained upon assembly....and even then, what happens when the chain line is loaded up and the swing arm line is pulled over, or the forks begin to twist under braking ? The things don't become unrideable.
I'm sure that it's worth doing if owners have a problem which has not responded to simpler checks but for normal road use, my impression is that only a small minority require this sort of work.
concours
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"You're contradicting yourself"
Nope, an out of context compilation.
" You imply close tolerances in this case are needless,"
Stand by it.
"then state a machine tool within 0.0005" is worn out"
Stand by it.
Garden variety mills hold repeatability better than .0001" http://www.teximp.com/view/userfiles/files/MAM72-63V(2).pdf
The mold machines hold sustained 1 micron positioning. http://www.matsuura.co.jp/english/conte ... -plus.html
"and then imply a frame can be aligned to required tolerances using plumblines, fuzzy string and a rule. "
Yup, see above.
" you've mentioned previously that your bike's "feel" is compromised and is "scary at some speeds/conditions" "
Nope, I never said MY bike is scary to me, but rather, "some speeds/conditions/riders".
"blueprinting of the frame will not make those inherent design traits go away"
Yup, stand by it.
"you have not ridden a Commando with a blueprinted frame."
You got me there. I've never ridden ANY bike with a blueprinted frame.
"The traits are not designed in, they are caused by the manufacturing process."
Your view on this topic. I happen to disagree. Your view suggests the engineers were capable of designing a masterpiece of a rubber mounting system, yet were not talented enough in the discipline of manufacturing engineering to reliably produce what they had designed. I think otherwise.
"Blueprinting i.e squaring axes, does cure the problems."
You say this because you believe it to be true. The precise work you did on your frame gave you great results. The whole package , using an improved design head steady, proper iso set-up, tires, etc. contributed.
Nope, an out of context compilation.
" You imply close tolerances in this case are needless,"
Stand by it.
"then state a machine tool within 0.0005" is worn out"
Stand by it.
Garden variety mills hold repeatability better than .0001" http://www.teximp.com/view/userfiles/files/MAM72-63V(2).pdf
The mold machines hold sustained 1 micron positioning. http://www.matsuura.co.jp/english/conte ... -plus.html
"and then imply a frame can be aligned to required tolerances using plumblines, fuzzy string and a rule. "
Yup, see above.
" you've mentioned previously that your bike's "feel" is compromised and is "scary at some speeds/conditions" "
Nope, I never said MY bike is scary to me, but rather, "some speeds/conditions/riders".
"blueprinting of the frame will not make those inherent design traits go away"
Yup, stand by it.
"you have not ridden a Commando with a blueprinted frame."
You got me there. I've never ridden ANY bike with a blueprinted frame.
"The traits are not designed in, they are caused by the manufacturing process."
Your view on this topic. I happen to disagree. Your view suggests the engineers were capable of designing a masterpiece of a rubber mounting system, yet were not talented enough in the discipline of manufacturing engineering to reliably produce what they had designed. I think otherwise.
"Blueprinting i.e squaring axes, does cure the problems."
You say this because you believe it to be true. The precise work you did on your frame gave you great results. The whole package , using an improved design head steady, proper iso set-up, tires, etc. contributed.
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concours said:
Oh boy could I have fun with this one. Claimed accuracy compared to actual accuracy, not to mention material temperature, type of material and a whole list of other variables. The real question is "how do you prove it?" Can you measure the finished piece to 1 micron and verify the acuracy...doubtful.
But honestly it really doesn't have much to do with what we are talking about. How accurate is accurate for a frame. The idea is to measure and verify positions and correct them. Take a variable out of the equation...if it exists. It can be better than it is. That's all. Does it need to be? For some yes, for other's no. I think we have verified that and we didn't need a caliper or a mill to do it
concours
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dennisgb said:concours said:
Oh boy could I have fun with this one. Claimed accuracy compared to actual accuracy, not to mention material temperature, type of material and a whole list of other variables. The real question is "how do you prove it?" Can you measure the finished piece to 1 micron and verify the acuracy...doubtful.
But honestly it really doesn't have much to do with what we are talking about. How accurate is accurate for a frame. The idea is to measure and verify positions and correct them. Take a variable out of the equation...if it exists. It can be better than it is. That's all. Does it need to be? For some yes, for other's no. I think we have verified that and we didn't need a caliper or a mill to do it
Remember, I didn't make the claims. The numbers quoted were stated in the document you linked us to. I merely challenged it based on the fact that it was marketing hype, doesn't pass muster, and continues to be. Run of the mill mills (NON mold) hold .0001". Japanese, American, even the low-cost Taiwanese stuff does.
"The real question is "how do you prove it?""
Ball bar test.
"Can you measure the finished piece to 1 micron and verify the acuracy...doubtful. "
The machine tool builder doesn't claim that, but rather positioning repeats to that level. The process of machining contains some variables.
"But honestly it really doesn't have much to do with what we are talking about. "
Only because the claims made, and then remade.
" You need to re-read my post regarding machining to +/-0.0005", I was referring to the accuracy of a typical vertical milling machine in the xy parameters."
It simply doesn't hold water.
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Just to put some things into perspective for those readers who would not normally work with close tolerances on a daily basis or have vocations in non mechanical areas.
The Norton Commando has a engine mounted via rubber donuts,the cradle that retains the engine and gearbox housing also holds the swing arm so obviously there is no rigid relationship between the rear wheel and both the steering head/front wheel.
Everyone knew that though.
+/- 0.001 inch has been mentioned,good luck with determining that with a device little more accurate than a vernier caliper and a bodgy old table with a few vee bocks. :lol:
Just to put 0.001 inch into laymens terms.
That is one thousandth of one inch.
A piece of paper is around four one thousandths of an inch thick,getting any part of the Commando frame or any other part associated with the frame within that range is pure fantasy let alone a quarter of it .
Don't tell me the trans case is checked and all machining and faced surfaces are somehow clocked to both shafts.
The same is done with the engine case to the PTO point of the crankshaft then that is somehow plotted to the output shaft of the transmission. :roll:
Given the wobble in the clutch even when new that might be deemed wishful thinking.
Lets not even go near the head steady. :lol:
Norton owners. :lol:
Just set it up to the best of your ability,replace any consumables as needed and ride the thing.
Two more added to the C U list.
The Norton Commando has a engine mounted via rubber donuts,the cradle that retains the engine and gearbox housing also holds the swing arm so obviously there is no rigid relationship between the rear wheel and both the steering head/front wheel.
Everyone knew that though.
+/- 0.001 inch has been mentioned,good luck with determining that with a device little more accurate than a vernier caliper and a bodgy old table with a few vee bocks. :lol:
Just to put 0.001 inch into laymens terms.
That is one thousandth of one inch.
A piece of paper is around four one thousandths of an inch thick,getting any part of the Commando frame or any other part associated with the frame within that range is pure fantasy let alone a quarter of it .
Don't tell me the trans case is checked and all machining and faced surfaces are somehow clocked to both shafts.
The same is done with the engine case to the PTO point of the crankshaft then that is somehow plotted to the output shaft of the transmission. :roll:
Given the wobble in the clutch even when new that might be deemed wishful thinking.
Lets not even go near the head steady. :lol:
Norton owners. :lol:
Just set it up to the best of your ability,replace any consumables as needed and ride the thing.
Two more added to the C U list.
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concours said:
Machine positional...sorry I was thinking finished part.
concours said:
Yes...the slippery slope of sales pitch...our machine is accurate but we can't help what "you" do with it. :shock: But in the end the finish product is still the result that the user needs accurate...sorry, I think you know why I don't want to go there given your experience in the field I'm sure you know where this is heading.
concours said:
I understood what you meant, and I agree positional tolerance of +/-0.0005" would be considered sloppy and even if it were machining tolerance for most precision apllications would be considered sloppy. We used to consider +/-0.0002" in finished part tolerance to be good...today that is just ok. Again, it doesn't have much to do with the discussion tho. The level of accuracy needed to "square" the frame is not that tight. But if a position is off by .040-.050 and you could bring it to +/-0.002" it would be better right? If there are mutiple variables if you eliminate one it is an improvement...eliminating the discussion of whether it is valuable or not. If you assume there is a way to assemble the components accurately then it is an improvement. Yours and others argument seems to be "What difference does it make I don't think I could tell the difference." That may or may not be true, and is purely judgemental, so not sure there is an answer to that...I am in the camp that thinks there can be an improvement...you and others are not. Like we said before it's okay to have different opinions.
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Time Warp said:
If the cradle that holds the engine, gearbox housing, swingarm and rear wheel are mounted in holes in the frame that are off position relative to the steering head, then the rear wheel is not in line with the front wheel. This is the "relationship" you are saying doesn't exist. The distance from the front tire contact surface to the rear tire contact surface multiples the error. This error can be corrected. Whether it improves handling is judgemental, but the error has been measured and does exist.
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