Project "Snow Drift"

[Oldskool 6,644]

11 minutes ago, 71_Bronco said:

Wait, wouldn't it be better to have pull points on the sides? So when you pull, the rollers will act as wheels?

 

If you pull from the front or back, won't the screws be fighting you the whole time?

 

Just a thought.

Very good point. If I'm stuck or towing something front and back make more sense.  If I break down....well..... i think it depends on what let's go.  I may have to make recovery skies that ratchet strap onto the screws to make it easier

[71_Bronco 1,072]

45 minutes ago, Oldskool said:

Very good point. If I'm stuck or towing something front and back make more sense.  If I break down....well..... i think it depends on what let's go.  I may have to make recovery skies that ratchet strap onto the screws to make it easier

 

Skis would make it easier too if the universal joint let's go too. Without that universal joint, I dont think it would roll, regardless of where you pull from.

[Oldskool 6,644]

12 hours ago, 71_Bronco said:

 

Skis would make it easier too if the universal joint let's go too. Without that universal joint, I dont think it would roll, regardless of where you pull from.

My thoughts exactly. I may devise a splint of sorts for that issue, to have on hand.

Edited January 24, 2021 by Oldskool

[rjg854 11,360]

Sounds logical prepare for the worst, and hope for the best. 

[Oldskool 6,644]

This is my least favorite part. Did I ever mention I HATE sanding.

[wallfish 16,994]

5 minutes ago, Oldskool said:

This is my least favorite part. Did I ever mention I HATE sanding.

Which is why I don't like to paint anything and go with the rat rod look

[Oldskool 6,644]

Just now, wallfish said:

Which is why I don't like to paint anything and go with the rat rod look

I like the ratrod look myself but every once in a while i end up painting something. I did one years ago and spot welded repair strips on the back of butt joints in the panels. Then drilled and stitched together using copper wire and barbed wire depending on the panel 

[ebinmaine 67,432]

24 minutes ago, Oldskool said:

spot welded repair strips on the back of butt joints in the panels. Then drilled and stitched together using copper wire and barbed wire depending on the panel

Sheer flippin brilliant. 

[SylvanLakeWH 25,535]

1 hour ago, Oldskool said:

I like the ratrod look myself but every once in a while i end up painting something. I did one years ago and spot welded repair strips on the back of butt joints in the panels. Then drilled and stitched together using copper wire and barbed wire depending on the panel 

Gonna need pics... 

[Oldskool 6,644]

10 minutes ago, SylvanLakeWH said:

Gonna need pics... 

I dont have any pics.That was about 15yrs ago. I lost alot of pics when my old desk top computer crapped out. 3 of us put it together for the guy who started it. The guy had a heart attach and had a pace maker put in. Knowing he was going to be laid up a for a while we figured we would help out. His wife gave us the key to the garage. When he was able to get out and about it was done. It was a '51 Ford F4 on an S-10 frame 350/350. Channeled 4in. Lowered 2in. It took 4 F1 rear fenders to make the rear wheel openings the same size as the fronts. He had 15x10in wheels on all 4 corners. It was a cool ride. 

[wallfish 16,994]

16 hours ago, Oldskool said:

  If I break down....well..... i think it depends on what let's go.

The conundrum of supporting the side load on the U joints is definitely an interesting problem to solve. There's certainly different ways to approach it but would something like this work to support them since you want to keep them in place? Not sure 3" pipe is the right size or if the bearing has enough angle movement to match the amount of movement for the front of the screw but just assuming the larger bearing would have more than smaller ones. Again, just another $0.02 thinking about possible solutions and trying to light the bulb while spending your time and money. (Those large bearings can get expensive. $75 or so)

 

[Handy Don 12,214]

21 minutes ago, wallfish said:

The conundrum of supporting the side load on the U joints is definitely an interesting problem to solve. 

Spoiler alert: This is a bit technical by a one-time mechanical engineer.

 

I tried setting this up as a "sum of forces" model, just to see scale and direction, with the joint at different positions in its rotation.

Came away realizing that it all comes down to:

- strength of the castings holding the pivot bearings -- probably adequate since they are already supporting similar or greater loads to transmit power

- strength of the bearings and races -- longitudinal -- again, seem to already be strong enough to transmit power, the longitudinal forces are new but are in the same planes as the rotational forces and seem to be well within the symmetric bearings' capabilities, 

- strength of the bearings and races

   -- lateral with inner "T" at horizontal/vertical -- the added "supporting" forces for the horizontal shaft of the joint's inner "T" resolve into the same directions on the bearings and races as do the rotational forces in the "standard" use; depending on the amount of "play" in the bearings, there may be some force pushing "sideways" on the vertical shaft's bearings

  -- lateral with inner "T" at 45º angle -- the added supporting forces are shared by all four arms of the "T" and at each bearing the force is split between being in the plane of the bearing (all good) and at 45º to that plane (i.e. tending to push the bearing's inner race sideways, kinda like a WH PTO on an engine crankshaft).

 

So that incremental load of each joint's share of the machine weight + operator + "bumps" varies from being borne by fully and "in plane" by the two bearings at the horizontal "T" to being 50-50 and angularly on all four bearings when the "T" is at 45º

 

So, to me, it is the strength and capacity of the bearings to handle the 45º loading over time that is the key to the machine's durability. I'm going with it working fine for what @Oldskool has in mind.

 

 

[Oldskool 6,644]

@Handy Don that was quite a mouth full. Thank you for doing the equations. Well I'm no engineer, but knowing the forces that a U joint can be subjected to I'm not sure but I would be more concerned with the force applied to the retaining clips. I think they will give it up before the yoke portion. Especially on a hard hit in the downward direction. As with any prototype there will be failures. @wallfishmay have a good point with support but also there are also u joint upgrades with less restructuring. Until I do break something I wont know what to upgrade. As far as u joint upgrades go I could go up a size or two. Maybe from a 3/4 ton truck? Maybe a gravel truck or school bus? The later would use something more like this.

[Ted Gardner 36]

how about some type of a slip clutch on the power side of the u joints? if you don't over extend the allowable angle of the u joint  whats the worry? you could also put stops on the front and rear axles 

Edited January 24, 2021 by Ted Gardner

[wallfish 16,994]

1 hour ago, Handy Don said:

Spoiler alert: This is a bit technical by a one-time mechanical engineer.

 

I tried setting this up as a "sum of forces" model, just to see scale and direction, with the joint at different positions in its rotation.

Came away realizing that it all comes down to:

- strength of the castings holding the pivot bearings -- probably adequate since they are already supporting similar or greater loads to transmit power

- strength of the bearings and races -- longitudinal -- again, seem to already be strong enough to transmit power, the longitudinal forces are new but are in the same planes as the rotational forces and seem to be well within the symmetric bearings' capabilities, 

- strength of the bearings and races

   -- lateral with inner "T" at horizontal/vertical -- the added "supporting" forces for the horizontal shaft of the joint's inner "T" resolve into the same directions on the bearings and races as do the rotational forces in the "standard" use; depending on the amount of "play" in the bearings, there may be some force pushing "sideways" on the vertical shaft's bearings

  -- lateral with inner "T" at 45º angle -- the added supporting forces are shared by all four arms of the "T" and at each bearing the force is split between being in the plane of the bearing (all good) and at 45º to that plane (i.e. tending to push the bearing's inner race sideways, kinda like a WH PTO on an engine crankshaft).

 

So that incremental load of each joint's share of the machine weight + operator + "bumps" varies from being borne by fully and "in plane" by the two bearings at the horizontal "T" to being 50-50 and angularly on all four bearings when the "T" is at 45º

 

So, to me, it is the strength and capacity of the bearings to handle the 45º loading over time that is the key to the machine's durability. I'm going with it working fine for what @Oldskool has in mind.

 

 

That's awesome. 

I can only guess on things like that and just go by "feel". Backyard hammer mechanic style which typically includes lots of trial and error after some half ass engineering. I don't know how to come up with the bounce type of forces involved other than it's going to be "a lot". LoL  Like pushing on it with a hammer vs hitting it with a hammer.

Just from reading the prior posts about it and considering they aren't necessarily designed for side load, I took that as a challenge to try and come up with something off the top of my head to support them without changing the original design. From an engineering stand point, would my half ass engineering drawing even work to support the U joint? The other point of it was if the U joint fails the machine wouldn't drop to the ground.

Retaining clips are certainly and easy point of failure like @Oldskool posted. I've had them pop off of stuff too. Again, I have absolutely no idea how much force those things can hold.

 

Edited January 24, 2021 by wallfish

[Oldskool 6,644]

3 minutes ago, Ted Gardner said:

how about some type of a slip clutch on the power side of the u joints? if you don't over extend the allowable angle of the u joint  whats the worry?

An over extension of the angle will never happen with the articulation I have. As far as being worried. I'm not worried till something breaks

[Oldskool 6,644]

1 minute ago, wallfish said:

That's awesome. 

I can only guess on things like that and just go by "feel". Backyard hammer mechanic style which typically includes lots of trial and error after some half ass engineering. I don't know how to come up with the bounce type of forces involved other than it's going to be "a lot". LoL  Like pushing on it with a hammer instead of hitting it with a hammer.

Just from reading the prior posts about it and considering they aren't necessarily designed for side load, I took that as a challenge to try and come up with something off the top of my head to support them without changing the original design. From an engineering stand point, would my half ass engineering drawing even work to support the U joint?

Retaining clips are certainly and easy point of failure like @Oldskool posted. I've had them pop off of stuff too. Again, I have absolutely no idea how much force those things can hold.

 

I say run the crap outta it till something flies apart. Being a hammer mechanic myself all I can do is build, break,replace with bigger parts. " insert toolman grunt" 😄😄

[wallfish 16,994]

2 minutes ago, Oldskool said:

I say run the crap outta it till something flies apart.

I'm the same way. It's called R&D

[Ted Gardner 36]

well sir I didn't mean to insult you i'll just back out of here and shut my mouth.

[Oldskool 6,644]

Just now, Ted Gardner said:

well sir I didn't mean to insult you i'll just back out of here and shut my mouth.

I'm not insulted at all. Input is the key here.  Sorry if I insulted you with my response. I didnt mean to at all. My u joints at full tilt are just barely beyond being straight. I plan on running the crap out of it just to see what does break. I would rather have something dependable then a dust collector in the garage

[wallfish 16,994]

 @Ted Gardner

Some of the earlier posts made were considering the side load on the U joints by having the weight and bounce forces applied to them vertically from the way they are being used. Not so much the turning forces to drive them. Don't run away! We are glad to have everyone's input as that's how we all learn here. This place is better than a university's Zoom meeting!

[Oldskool 6,644]

Just now, wallfish said:

 @Ted Gardner

Some of the earlier posts made were considering the side load on the U joints by having the weight and bounce forces applied to them vertically from the way they are being used. Not so much the turning forces to drive them. Don't run away! We are glad to have everyone's input as that's how we all learn here. This place is better than a university's Zoom meeting!

X2

[DennisThornton 4,769]

On 1/21/2021 at 4:04 PM, Oldskool said:

I put 4 dips on the handles. Now that they are dry I kinda like it. I also used some to fix a torn dampener boot. I put a couple wraps of electrical tape on it. Then brushed some tool dip over it. I like the results for that as well.

I like to try to slip tubing, heat shrink or something over first and then build up the dip coating.

 

 

[DennisThornton 4,769]

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.

[Handy Don 12,214]

 

1 hour ago, Oldskool said:

I would be more concerned with the force applied to the retaining clips. I think they will give

 

Agree on this. I guess with enough force, one should shear off and the bearing come out or, more likely, the forces could wear the groove that holds it and it could slip out. In the normal use case for a U-joint, there is little or no force on these clips unless the joint is misaligned. Your point is valid that switching to a joint with a "captive" yoke not dependent on spring clips would be the next level up. Once you take that away, you are back to side load on bearings--wonder it any of these use tapered?