Sunday, December 6, 2009

holding pattern taking hold

First, my Thanksgiving was great. I hope yours was as well. Today's post covers some highlights of that trip, a bus update and looking forward.

Thanksgiving
My family has a rare opportunity to use a friend's vacation home in Sun River, and we took some other friends with us. There was snow on the ground outside the house the whole time we were there, so the kids spent just about every waking minute outside. This left me and Mark able to watch the Lions and Dallas games as well as all that college football on Friday.
We hit Mt. Bachelor on Saturday. Although the folks back in Portland and the people we met in Sun River were saying the crowds would be unbearable, I thought it was unbelievably easy. The workers on the mountain said it was a busy day, but I don't remember waiting in a line for anything for more than a few minutes. The snow was dry and fast. I played with my younger son on the inner tube slope while my older got his first runs of the season on his snowboard. Good times.

Bus Update
On the bus front, though, there has been no progress. I was able to hit the hardware store for a bunch of washers and nuts, but I haven't had any time to focus on fabrication. Besides that, we are in the midst of a cold snap, bringing the overnight lows down into the teens and the daytime highs around freezing. Once the wind chill is added in, the temps drop down another 15 to 20 degrees. Not exactly the kind of weather I like to spend under the bus. Instead, I have spent the last 2 days clearing English Ivy and raking up the leaves in my yard. I like having the leaves gone before snow hits, and there was talk of snow for early this week. Yikes. I was able to get all of the other yard tasks completed, though, so I can move the bus once I either borrow or buy a come-along so I can pull him up the incline. I hope to do that next weekend.

Outlook
My wife leaves to visit her mom and brother on Wednesday. With her departure, our Christmas becomes very uncertain. We don't know how serious either of their respective conditions are because they haven't been terribly verbose with their descriptions. Maybe they don't know either. Regardless, my wife will probably be extending her stay, and we are planning for a just-before-Christmas return at best. The kids and I will busy ourselves with Christmas decorating and such, but it won't be the same. I don't sleep very well when she's not around, so I'll probably have nights to work on the bus if the temperatures would cooperate.

I'll post more when there's something to post about. I'd like to either get the radiator mounted or the bus moved or get the shrouding constructed or some combination of those 3 things before Christmas. In theory, there is time. It is converting that to practice that always seems to trip me.

Monday, November 23, 2009

Radiator mounting planned

I was fortunate to get a couple of hours on Sunday with limited distraction, so I rolled under the bus between showers and I believe i have a plan for mounting the radiator under the bus. I ran out to Lowes, got a bunch of hardware, and started what I believe to be the final run on the brackets before installing this beast. Most of today's post will deal with that. I have no further news about Tom or Marianne. My wife will be traveling to visit with them in a few weeks, so she'll dig up what's really going on when she's there.

Concerns
One of my lingering concerns about mounting a radidator under the bus is that it will be subjected to road debris abuse. Beyond just simple plastic bags, and gravel, there can be large obstacles in the road. I've seen mattresses, sheet rock, lumber, a ladder, etc, all in the last year on the Oregon highways. Add to that the ice and snow that we got last winter, where my Jetta was getting high-centered by the mid-road snow pack, and I think the concerns are justifiable. I have looked at many designs by different people, and they seem to fall into 2 categories: avoidance and strength.

Avoidance
The under-mount radiator designs that follow this pattern are purposely placed as flat as possible, and as close to the floor of the bus as possible. These achieve some degree of safety because the debris can't really get to them. The downside of this design is that the air can't get there naturally either so any cooling is done exclusively by fans. This puts considerable pressure on the system working correctly, leaving little margin for error for a failed fan. Some kind of fan monitoring should be used to indicate when the fans are on / off at the dashboard so the driver can know when the fan(s) has failed.

Strength
The under-mount radiator designs that follow this pattern are angled to catch the air, and have a cage of sorts around the radiator. This cage deflects debris from getting to the radiator, in theory. I would think that there is the possibility of high-centering or having the entire thing ripped off by passing debris, if the debris is something like a tree stump or some other non-movable object. These do have the benefit of naturally grabbing some air on its way by, so they can operate with some success if a fan(s) fails.

Flexibility
This is the pattern that I'm going to try. It is a take on the strength pattern, but allows for travel within the mounting so that the radiator mount can partially absorb, and partially avoid debris. This pattern should allow for natural air passage and the use of fans like the "strength" pattern, but with the ability to move up and down if a tree stump or other immovable object is traversed.

Implementation
First, I made the bracket relatively simply - it is just a simple "c" wrapping each of the 4 mount points on the radiator. These "c" wrappers then tied into one of 3 brackets - one for the front and 1 for each of the 2 rear. The front is a basic square tube the should assist in the strength of the front bracket while partially obstructing the temperature sensor from direct contact by flying debris. I covered this in previous postings.

To these brackets, I have attached eye-hooks. These eye hooks will connect, through chain, to eye-hooks that are connected to the cross-members under the belly of the bus (the point at the cross-member will be re-enforced with some extra steel). This chain will add the flexibility to move. To prevent the radiator from bouncing up into the floor of the bus, I will add a rubber travel-stop (think snubber from the front end). I will be able to vary the depth of the angle of the front end by adding or removing chain links. I have selected chain and single-links that can handle up to 450 pounds. Anything less seemed too thin and anything more seemed excessive.

Protection
Across the front bracket, I will attach a larger round pipe (like a 16" stretch of fencepost). This will serve as a bumper that will absorb the initial contact with the immovable object and cause the front lip to bounce up - at least that's the theory. Behind the post, I'll put in a security screen style grid to prevent larger rocks from getting past and into the radiator area.

Shrouding
Last, surrounding the floating radiator, I will put a small cowling / shroud. This will help guide the air to the radiator and keep the rad-heated air from recirculating when at a dead stop. This shroud won't be more than a half-dozen inches tall. If it were much taller, it would prevent the movement that the chain is allowing. If I can figure out a clever way, I'll curve the shroud so it rounds off at the top. This would allow the shroud to be taller. Regardless, it needs to be removable so I can get to the chain for maintenance.

That's it for today. I was able to get started on the eye-hooks, but I ran out of bolt-nuts, and daylight. I need to stop at the hardward store for lock washers and nuts. I doubt I'll have much more time before Thanksgiving to work on Hapy. I may not get any time on him for another week, actually, so, I won't post until after the holiday. Happy Thanksgiving, and thanks for reading.

Pictures:
top - the rear brackets with the eye-hooks attached. The long eye-hooks will go into the thick cross member in front of the transaxle
bottom - the front bracket with the long eye-hooks attached. These will be connected via a chain to one of the shorter cross members (which will be re-enforced / backed with some steel at the mount point)

Thursday, November 19, 2009

rad brackets continue

There's not much to add this time. I didn't get much time on the project these last few days, but I was able ot get a little bit further on the radiator bracket. I also have an update on my son's H1N1.

Radiator Bracket I finished the last of the 4 separate brackets. It went together like its twin on the front. After that, I put a bit of square-tubing across the front. After taking some measurements, and messing around with Google Sketchup, I have a working model of the underside of the bus. From this, I can conclude that I will have about 5-1/2" above the frame rail to play with. If I don't want more than 5 inches of drop on the front end, that gives less than 9 inches (after removing the thickness of the radiator) of possible exposure to air flow. I'll be getting under the bus this weekend, time and weather permitting. I hope to first figure out what to mount the front end to. Then, I'll start considering how I'll do that. I have a few ideas....

Front End Tie-In Ideas
First, there's the obvious bar across the beams and a couple of vertical-ish bars coming from the front of the radiator up to that cross-bar. Figure I tie-in some kind of rubber bit to absorb the vibration and torque-action on the body.
Second, I could put shorter vertical-ish bars up from the rad and connect to a cross bar (or eye-loops) with a short stretch of cable. This would make the pitch variable, so I could experiment a little.

Where Go Fans?
I could put fans under the radiator in a pull configuration. This seems to be the common thinking for best cooling, but wouldn't any water that passes through the radiator potentially get into the motor? I'm thinking that any time the fans would be in that condition, they would probably be turning on with some regularity, but its still something to think about.
Maybe the fans go on top in a push configuration. Then, any road debris could bounce up and damage a fan. Of course, if the fans weren't there, that debris would have damaged the radiator, so there will have to be some kind of security screening to protect the top of the radiator anyway.

Shroud Cowl
The picture that I linked in an earlier posting didn't have any shrouding at all. I don't know where his bus lives, so maybe it doesn't get very hot. I think I want at least some cowling on the sides and rear to prevent rad-heated air to re-flow through. In both of the design options above there would be a vertical-ish riser at the front on both corners. I'd need something at the rear to tie into. I'll have to give that some thought. Maybe it would just be a matter of careful cutting and I could re-use the shroud mount point that I'm using for the brackets.

Cedar's H1N1
Well, Cedar finished his battle with the flu and was back at school today. He came bounding downstairs all dressed and ready to roll after over-sleeping for a school day. He made it to school only 30 minutes after the late bell. Thanks for your words of concern. We have no updates on Marianne or Tom. I'll post as we learn what's going on.

pictures:
top - front rad bracket before attaching to radiator. That's a 12" ruler for perspective.
top middle - view along bracket from water sensor end of radiator.
bottom middle - bracket at water temp sensor. Note the sensor maintenance is not affected.
bottom - full view of radiator with front and rear brackets attached.