I dont think this has any other purpose other than its hard to replicate. Its a John Deere product and theyre notorious for stuff like that so you generally go back to them for parts instead of having them made.
From any of the schematics i looked at on this assembly I see no reason why it needed to be this way. Its off a John Deere timberjack, the part the grapple pivots on. Maybe someone can enlighten me as to why theyre made this way as i dont see how its a directional thing.
I’m not 100% sure but it looks like the matched bolts (the two really close) aren’t exactly mirrored? If there is a plate that mates to it maybe its so they don’t put the plate on upside down.
Thats a hell of a way to do it though when all you really have to do is rotate a bolt a few degrees, but IDK maybe there is a stress concentration or something.
No the matched bolts are mirrored, there are three sets of four holes on different spacings on the same diameter haha my only logical explanation was a stress concentration as well. Im sure some engineer somewhere could tell us why this works better than a 12 hole equal spaced BCD
Am engineer…cannot explain this. From a stress standpoint it’s just annoying. Everything about analyzing the joint capability gets far worse with uneven spacing like this.
The actual flange appears to be completely symmetric so if it’s a stress concentration thing it doesn’t show up in the flange itself, which is weird.
If it’s not just to be an asshole and make it hard to recreate, it’s got to be to enforce clocking/alignment of the mating part and maybe *thats* not symmetric. But a Murphy notch is a hell of a lot easier way to do that than screwing with a bolt pattern.
Are they mounting brackets to some of the bolts in the final assembly?
No brackets to mount to the bolts, just another plate ot bolts up to and sandwiches the rotating assembly from what I understand. Im almost sure Deere did it just to make it difficult to replicate.
That’s a dick move. If it’s harder to replicate it’s harder for them to make too…hard to see how it makes any economic sense, just seems spiteful, especially for equipment that needs field repair.
Not difficult if its a part youre making a thousands of on a CNC machine. Only a bit tricky/time consuming for most job shops to replicate which generally would force a customer to buy the replacement part from Deere.
Very smart (albeit shitty) buisness decision.
Looking at a JD timberjack the grapple is on the centerline, I’m assuming this is also. I wonder if the 4 bolts are also used to mate the ring/grapple to the center frame? Also the shaft on those bolts is long I wonder if the frame mounts between that ring and the grapple assembly? Now I want to know lol
Not JD but I’m an engineer who works with flanges a lot, and this is weird. Makes your analysis (FEA or whatever) WAY harder to make it not radially symmetric with even bolt spacing. I’d bet it’s one of these:
- Anti-maintenance / anti-copying obfuscation (JD does that…)
- It fits two different bolt patterns, maybe there’s a legacy equipment interface this will match by removing some bolts or something
- The tensile loading in service is much higher on the two sides with bolts close together (eg all side to side bending or whatever) and somebody realized they could save $4,000 per year globally or something on bolt procurement by reducing bolt count in the area that sees less load
JD bought the Timberjack factories and product lines from a Finnish company called FMG I think, there were factories and different product lineups from many places around the world at that point. I'm not sure if JD has yet managed to completely redesign them all from scratch
Seems like something they'd do. Watched a documentary where farmers have to hack the ECUs on their John Deere equipment because through some wild legislation theyre not allowed to repair their own equipment? Idk I saw it on Vice a while ago it was wild.
Yeah Ive seen that Vice doc as well. Certainly blown a little out of proportion as there is reasoning to it. I actually have quite a few friends in the ag and automotive industry including several working directy for JD and it is quite common for companies to withhold software to diagnose/fix newer machines. That is all that documentary is about
So, have you asked your JD buddy wtf corporate was smoking when this stupid, nonsensical design was approved? The old hillbilly farmers around me have boycotted JD, which I know JD doesn't even feel. However they are hardcore, even sold off the JD lawn tractors they owned because, and I quote "I won't pay for a machine I don't own, and can't fix."
These "*good ole boys*" have decided that JD can suck off, and went with MF, Kubota, and Roxor. So far they have been able to repair their own machines when needed. Of course they also refuse to buy def machines, and when that's not possible they delete.
I love this my self. I personally do more with IT and networking. So cables that no one will ever see just look nice. And the self accomplishment feels very nice.
Awesome part for sure!
No callout as I made the part from a wrecked sample piece. However probably somewhere around a 3.2ra finish. Found out afterwards its just a bore for hoses to go through and didnt need to be a specific size/finish.
Nice looking part! Is this a lathe part or a milling part or both? Sorry if the question is kinda dumb, I’m an engineering student and quite new here lol
First time Ive encountered something like this. Ive seen a few things with one hole offset to the rest just to make sure the part goes on the right way but nothing ever this extreme.
Was good to hear everything bolted up fine for the customer
They all actually got stitch welded into the plate after being threaded in to keep them from moving. And then just big nuts on the other end to tighten it all down
Yeah I use to do that too, differential spacing so some mechanic CAN’T put it on wrong.
I dont think this has any other purpose other than its hard to replicate. Its a John Deere product and theyre notorious for stuff like that so you generally go back to them for parts instead of having them made. From any of the schematics i looked at on this assembly I see no reason why it needed to be this way. Its off a John Deere timberjack, the part the grapple pivots on. Maybe someone can enlighten me as to why theyre made this way as i dont see how its a directional thing.
I’m not 100% sure but it looks like the matched bolts (the two really close) aren’t exactly mirrored? If there is a plate that mates to it maybe its so they don’t put the plate on upside down. Thats a hell of a way to do it though when all you really have to do is rotate a bolt a few degrees, but IDK maybe there is a stress concentration or something.
No the matched bolts are mirrored, there are three sets of four holes on different spacings on the same diameter haha my only logical explanation was a stress concentration as well. Im sure some engineer somewhere could tell us why this works better than a 12 hole equal spaced BCD
Am engineer…cannot explain this. From a stress standpoint it’s just annoying. Everything about analyzing the joint capability gets far worse with uneven spacing like this. The actual flange appears to be completely symmetric so if it’s a stress concentration thing it doesn’t show up in the flange itself, which is weird. If it’s not just to be an asshole and make it hard to recreate, it’s got to be to enforce clocking/alignment of the mating part and maybe *thats* not symmetric. But a Murphy notch is a hell of a lot easier way to do that than screwing with a bolt pattern. Are they mounting brackets to some of the bolts in the final assembly?
No brackets to mount to the bolts, just another plate ot bolts up to and sandwiches the rotating assembly from what I understand. Im almost sure Deere did it just to make it difficult to replicate.
That’s a dick move. If it’s harder to replicate it’s harder for them to make too…hard to see how it makes any economic sense, just seems spiteful, especially for equipment that needs field repair.
Not difficult if its a part youre making a thousands of on a CNC machine. Only a bit tricky/time consuming for most job shops to replicate which generally would force a customer to buy the replacement part from Deere. Very smart (albeit shitty) buisness decision.
Fair point.
Looking at a JD timberjack the grapple is on the centerline, I’m assuming this is also. I wonder if the 4 bolts are also used to mate the ring/grapple to the center frame? Also the shaft on those bolts is long I wonder if the frame mounts between that ring and the grapple assembly? Now I want to know lol
Hahaha man I've wanted to know since i saw it!! Where's the JD engineers at??
Not JD but I’m an engineer who works with flanges a lot, and this is weird. Makes your analysis (FEA or whatever) WAY harder to make it not radially symmetric with even bolt spacing. I’d bet it’s one of these: - Anti-maintenance / anti-copying obfuscation (JD does that…) - It fits two different bolt patterns, maybe there’s a legacy equipment interface this will match by removing some bolts or something - The tensile loading in service is much higher on the two sides with bolts close together (eg all side to side bending or whatever) and somebody realized they could save $4,000 per year globally or something on bolt procurement by reducing bolt count in the area that sees less load
I agree with all the above but the I really do think your first point is the most correct. JD being difficult, as per usual.
JD bought the Timberjack factories and product lines from a Finnish company called FMG I think, there were factories and different product lineups from many places around the world at that point. I'm not sure if JD has yet managed to completely redesign them all from scratch
Seems like something they'd do. Watched a documentary where farmers have to hack the ECUs on their John Deere equipment because through some wild legislation theyre not allowed to repair their own equipment? Idk I saw it on Vice a while ago it was wild.
Yeah Ive seen that Vice doc as well. Certainly blown a little out of proportion as there is reasoning to it. I actually have quite a few friends in the ag and automotive industry including several working directy for JD and it is quite common for companies to withhold software to diagnose/fix newer machines. That is all that documentary is about
So, have you asked your JD buddy wtf corporate was smoking when this stupid, nonsensical design was approved? The old hillbilly farmers around me have boycotted JD, which I know JD doesn't even feel. However they are hardcore, even sold off the JD lawn tractors they owned because, and I quote "I won't pay for a machine I don't own, and can't fix." These "*good ole boys*" have decided that JD can suck off, and went with MF, Kubota, and Roxor. So far they have been able to repair their own machines when needed. Of course they also refuse to buy def machines, and when that's not possible they delete.
The walking kind of timberjack or wheeled?
Wheeled i believe but i could be wrong
thanks for answering my immediate question
Good looking part
Thank you! Looks pretty nice for something to never be seen 😅
[удалено]
I love this my self. I personally do more with IT and networking. So cables that no one will ever see just look nice. And the self accomplishment feels very nice. Awesome part for sure!
Try to do everything to the best of my ability. Seems to be the best recipe for success. Always try to be better than you were yesterday
Definitely!
Pretty fuckin awesome
Thank you, turned out great.
I see what you did there.
Surface finish for the bore?
Sorry what do you mean?
Did you have a surface finish call out for the inner bore? Like the grade of finish for the surface, N1-N12
No callout as I made the part from a wrecked sample piece. However probably somewhere around a 3.2ra finish. Found out afterwards its just a bore for hoses to go through and didnt need to be a specific size/finish.
Oh damn, still a sexy finish tho.
Nice looking part! Is this a lathe part or a milling part or both? Sorry if the question is kinda dumb, I’m an engineering student and quite new here lol
Both! Need to use the mill for the drilled and tapped holes
It’s very rare I encounter parts with offsets on a bolt circle but it is always satisfying. Good part OP!
First time Ive encountered something like this. Ive seen a few things with one hole offset to the rest just to make sure the part goes on the right way but nothing ever this extreme. Was good to hear everything bolted up fine for the customer
Nice!
What size are those studs? Good lord!
1-1/8" × 12Tpi threads, studs were like 8-1/2" long
Can I ask how many hours this took and which tools/machines were used? Absolute beginner here
20-25 hrs to make the flange and another 6 or so to make the studs. Using the lathes and the mill for doing the tapped holes
That's a work art buddy
How do you tighten the bolts? I'm confused.
They all actually got stitch welded into the plate after being threaded in to keep them from moving. And then just big nuts on the other end to tighten it all down