Project "Snow Drift"

[Oldskool 6,644]

19 minutes ago, DennisThornton said:

I mentioned this earlier.  I think both ends of the screw needs lateral support, not just the front. Both ends need to allow the shaft to change angles a bit.  The front allows this already but I think the rear should as well.  I posted a poor representation as this:

instead of a better choice like this:

Mounted in a brace to give side to side support.  I picture the drive sprocket in rigid support, then the U-joint, then this proposed bearing in another rigid support to the frame and THEN the screw with pillow at end.  I think thrust bearings are also needed.  Maybe even a splined shaft to allow for movement.

I really think in that case it would need a slip shaft of some sort 

[DennisThornton 4,769]

Gonna need thrust washers or thrust bearings at least.  Both those screws have to push against something to move the beast.  Wear points pushing against the front axle when going forward, every rotation.  Hopefully won't need the splines but we've already gotten out of my comfort zone.

 

And I still have concerns about the u-joints.

[wallfish 17,000]

38 minutes ago, DennisThornton said:

Mounted in a brace to give side to side support.  I picture the drive sprocket in rigid support, then the U-joint, then this proposed bearing in another rigid support to the frame and THEN the screw with pillow at end.  I think thrust bearings are also needed.  Maybe even a splined shaft to allow for movement.

A problem with doing that is the shaft section behind that rigid supported bearing will move out of alignment in a way in which the the U Joint can't handle or renders it useless to swivel. The swivel point of a support bearing must be in the same plane as the U joint swivel point if he wants to keep the sprocket from tilting at all.

[Oldskool 6,644]

4 minutes ago, DennisThornton said:

Gonna need thrust washers or thrust bearings at least.  Both those screws have to push against something to move the beast.  Wear points pushing against the front axle when going forward, every rotation.  Hopefully won't need the splines but we've already gotten out of my comfort zone.

 

And I still have concerns about the u-joints.

Leaving everything else aside what part of the u joint do you figure will fail? 

[Oldskool 6,644]

Dont forget. It pushes as much as it pulls. So the directional force is divided x2. Also dont forget the rear hub contains 2 tapered wheel bearings on that 1in shaft. Yes I guess that may put some pulling force on the u joint but I'm not skidding logs with this. 

[wallfish 17,000]

1 minute ago, Oldskool said:

Leaving everything else aside what part of the u joint do you figure will fail? 

I'm with @Handy Don and think it should be fine just like it is. Sorry to open the proverbial "can O worms" with my earlier post. It was just bothering me I didn't have a good solution if the side load on the U joint was a problem and how to overcome that if it was a problem.

 

The shafts of the screws are locked in the existing bearings to push pull the machine. Unless we are considering the side load on those bearings now?????

Let's just wait for Oldskool's R&D program to determine what, if anything, could use attention.

[DennisThornton 4,769]

14 minutes ago, wallfish said:

A problem with doing that is the shaft section behind that rigid supported bearing will move out of alignment in a way in which the the U Joint can't handle or renders it useless to swivel. The swivel point of a support bearing must be in the same plane as the U joint swivel point if he wants to keep the sprocket from tilting at all.

I think you are right!  Too great a swing in that very short distance.  Just changed the problem instead of eliminating it...  Earlier I mentioned CV joints.  Not sure what their range is though.

[DennisThornton 4,769]

17 minutes ago, Oldskool said:

Leaving everything else aside what part of the u joint do you figure will fail? 

Too much side pressure.  To me they just allow a little flex, a little change in direction.  And I think John is correct that my recent comment is still asking too much of them.

[Oldskool 6,644]

1 minute ago, wallfish said:

I'm with @Handy Don and think it should be fine just like it is. Sorry to open the proverbial "can O worms" with my earlier post. It was just bothering me I didn't have a good solution if the side load on the U joint was a problem and how to overcome that if it was a problem.

 

The shafts of the screws are locked in the existing bearings to push pull the machine. Unless we are considering the side load on those bearings now?????

Let's just wait for Oldskool's R&D program to determine what, if anything, could use attention.

Open all the cans of worms you want. lol I think what @DennisThorntonis getting at is something like this pic.

[Oldskool 6,644]

Just now, DennisThornton said:

Too much side pressure.  To me they just allow a little flex, a little change in direction.  And I think John is correct that my recent comment is still asking too much of them.

But what part in particular? The yoke? The clip? The needle bearings?  All this talk about them has given me ideas but I'm trying to narrow down the retrofit

[Oldskool 6,644]

Also I want to mention. I put my angle finder on the shaft in the resting position. In full tilt the shaft changes by about 5degree.

[wallfish 17,000]

9 minutes ago, Oldskool said:

Open all the cans of worms you want. lol

I'll need to know the dollar budget amount for this project to do that. LoL  

 

 

Edited January 24, 2021 by wallfish

[DennisThornton 4,769]

3 minutes ago, wallfish said:

I'll need to know the dollar budget amount for this project to do that. LoL  

 

 

Now you join in!  We needed you earlier!

[DennisThornton 4,769]

33 minutes ago, Oldskool said:

Also I want to mention. I put my angle finder on the shaft in the resting position. In full tilt the shaft changes by about 5degree.

Your tilt was fine.  Mine too much!  Problem is every U-joint I've seen had lateral support at each end.  Like a flex-joint between an engine or motor and whatever it is driving.  But both the motor and whatever has supported STATIONARY shaft.  

Edited January 24, 2021 by DennisThornton
supported STATIONARY shaft.

[DennisThornton 4,769]

Supported STATIONARY shaft at each end. U-joint in the middle.

[Handy Don 12,232]

12 minutes ago, DennisThornton said:

Your tilt was fine.  Mine too much!  Problem is every U-joint I've seen had lateral support at each end.  Like a flex-joint between an engine or motor and whatever it is driving.  But both the motor and whatever has supported shaft.  

Exactly! This is an "out of the box" approach that doesn't align with our preconceived notions of how u-joints should be used! If the joint's parts can handle the side loading it'll work. 

 

One other thought, I wondered about what failure would look like, should it occur.

My guesses:

If one of the cast/forged arms of an end piece breaks, then the joint comes completely apart within a couple of revolutions but there are few loose pieces.

If a bearing fails, the joint will stay together but each revolution will start to damage other parts quickly and, again, few loose pieces.

If a bearing comes off the end of a yoke arm and is ejected (i.e. retaining ring failure) it could get thrown but since the screws are not turning very fast it'll not be with much force--again, the joint stays together but becomes increasingly damaged quickly.

[DennisThornton 4,769]

If there was a simple way to beef it up now I would.  Other approach is to use it at low speed at first and see what wears before it fails.  But it would be rather aggravating if the screws or frame needed altering.

 

I want to see some snow fly!  But I'd like it to turn out well too.

[Oldskool 6,644]

So for now I have a couple of ideas .

 

1: drill and tap for 5/16 at the yellow tape and make some thick washers to help support the ujoint caps.

 

2: use the caps off the tanks. Cut the top off where it starts to round. It wont help in support but it actually would if the ujoint fails. It also has a hole big enough the service the joint.

[DennisThornton 4,769]

2 minutes ago, Oldskool said:

So for now I have a couple of ideas .

 

1: drill and tap for 5/16 at the yellow tape and make some thick washers to help support the ujoint caps.

 

2: use the caps off the tanks. Cut the top off where it starts to round. It wont help in support but it actually would if the ujoint fails. It also has a hole big enough the service the joint.

Explosion proof bellhousing! 

If the U-joint was on the other end where the screw would flop around at failure I'd be more than just concerned but if this joint fails you will just make a very quick turn.

 

I think it will turn and move along as is but I also think it is the weak link and fail.  When?  I surely don't know.

[Oldskool 6,644]

Just now, DennisThornton said:

Explosion proof bellhousing! 

If the U-joint was on the other end where the screw would flop around at failure I'd be more than just concerned but if this joint fails you will just make a very quick turn.

 

I think it will turn and move along as is but I also think it is the weak link and fail.  When?  I surely don't know.

The cap also will keep the screw from coming out of alignment at ujoint failure making it easier for retrieval and loading. Instead of the rear strut just hitting the ground

[DennisThornton 4,769]

1 minute ago, Oldskool said:

The cap also will keep the screw from coming out of alignment at ujoint failure making it easier for retrieval and loading. Instead of the rear strut just hitting the ground

Wasn't thinking that far ahead but that is something to consider.  That turn could be much quicker than I thought! 

 

OK, I'm rather concerned again!  We need you for other projects AFTER you finish this one.  Don't want you out on disability!  Maybe you should have some more bacon snacks and give others a chance to chime in.  I Googled trying to find how augers pushing in one direction used bearings and thrust bearings but even that doesn't quite cover this situation.  I've not research CV joints yet but they may be a more durable approach.  I've made things but invented little, rather coping ideas...

[Pullstart 62,889]

If there’s room, if there’s that much concern, if you have time... Driveshaft carrier bearing from a heavy duty truck?  

[DennisThornton 4,769]

2 minutes ago, pullstart said:

If there’s room, if there’s that much concern, if you have time... Driveshaft carrier bearing from a heavy duty truck?  

Room? Where?  Not even a drive shaft...  

However, could try to utilize that idea as a safety catch, if not some support, even if it's no more than a no contact ring with brace back to the frame.  It could catch a wayward screw and keep it pretty much in place.

[Oldskool 6,644]

7 minutes ago, pullstart said:

If there’s room, if there’s that much concern, if you have time... Driveshaft carrier bearing from a heavy duty truck?  

I dont have the room. There is about 6in 

[DennisThornton 4,769]

I've been using a wrong term, this might help us with those.

I'm concerned with axial and transverse loads.  I think these u-joints are more than adequate for the twisting torsional load including some change in angle.  I see a need for thrust washers for the axial loads and u-joints weren't meant for the transverse loads.  Not saying they won't work for a while but they weren't made for transverse loads.

 

U-joints can do this just fine:

commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, connected by a cross shaft.  

 

Flexible couplings are designed to transmit torque, whilst permitting some axial, radial and angular misalignment.

 

I think U-joints need support at both ends.