Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Realmccoy on May 11, 2017, 11:36:22 am
Title: Working under Unihome
Post by: Realmccoy on May 11, 2017, 11:36:22 am
I've read the posts about safety supports and had eight pieces cut that were 11 1/2 inches tall. I've raised the coach up, put them in place. Do you then lower the coach to make contact with the support pieces?
Title: Re: Working under Unihome
Post by: Tim Fiedler on May 11, 2017, 11:42:39 am
Yes
Title: Re: Working under Unihome
Post by: John Haygarth on May 11, 2017, 11:43:07 am
yes, or if air is lost by leaks they will make contact anyway. I drop bags as that holds them tight in place so no chance of falling out (but realistically they should not fall out anyway) JohnH
Title: Re: Working under Unihome
Post by: Realmccoy on May 11, 2017, 01:03:40 pm
Thanks I thought lowering would provide greatest safety but noticed bags held up well.
Title: Re: Working under Unihome
Post by: Mark Duckworth on May 11, 2017, 04:46:08 pm
I ordered 4 pieces of tube stock today. 2 x 2 x 11-1/2 with 0.25" wall thickness. Measured under the coach first with airbags fully raised just to confirm that the 11-1/2's will fit. Pretty affordable although freight just about equaled the materials!. Will slap a quick coat of spray paint on them just to keep rust away.
Title: Re: Working under Unihome
Post by: wolfe10 on May 11, 2017, 04:58:05 pm
Mark,
With 4, unless you are working on the air suspension (in which case you will need to dump air), leave the air bags UP. Because there are 4 bags PER AXLE, you will be putting some torque on things by dumping air with just the inner safety stand location (vs one stand inboard of each air bag). Not a big deal-- nothing is going to break, but you gain nothing by dumping the air.
Title: Re: Working under Unihome
Post by: Mark Duckworth on May 11, 2017, 05:06:58 pm
With 4, unless you are working on the air suspension (in which case you will need to dump air), leave the air bags UP. Because there are 4 bags PER AXLE, you will be putting some torque on things by dumping air with just the inner safety stand location (vs one stand inboard of each air bag). Not a big deal-- nothing is going to break, but you gain nothing by dumping the air.
Ah, I see your point. I'll order 4 more. Thanks, Brett.
Title: Re: Working under Unihome
Post by: Don & Tys on May 11, 2017, 05:15:56 pm
To amplify Brett's point, here a quote from a post I made in another thread awhile back;
Quote
Which corners do you block, especially in the back? My observation is that putting blocks on only one end of the "H" frame is like a loading one end of a teeter-totter. Putting the blocks in front of the rear axle for instance will push that end (the one connected to the bulkhead joint by the trailing arms) away from the basement. That is in essence how I controlled the separation of the bulkhead joint the entire time I was rebuilding the basement structure. If your bulkhead joint is sound, it would likely be okay with that extra loading, especially if the air bags don't get dumped or leak down. But knowing what I know and seeing what I have seen, I would advise against that option for work that would have the coach sitting heavily on the stands. If it is to do a quick check under one area, then blocking one end could be a life saver. If however, working with the air bags dumped or removed, I would not set the coach down with just one stand in front of each end of the rear axle. Not only is it safer in the event of a catastrophic sir system failure to hold pressure, but it is less stressful on the structure, IMHO. When I am blocking the coach all the way up for some serious work, I always use 8 stands because it gives me the warm fuzzies to do so ;) . If the work is all focused on one end, say the rear, then I will possibly block up the rear with four and just use two in front as a just in case option. The front suspension is not tethered to the front bulkhead joint like the rear because there are no trailing arms acting as an axle locator, so using two in the front would still put stress on the suspension components in the event of an air dump, but the basement to bulkhead joint would not be unaffected. Of course everyone must do what their own assessment of the physics of the situation tells them is best. Don
Ah, I see your point. I'll order 4 more. Thanks, Brett.
Title: Re: Working under Unihome
Post by: Pierce & Gaylie Stewart on May 11, 2017, 05:26:43 pm
Don has had the experience of a lifetime with his coach. And in a poor work environment. I would listen very closely to what he says about working under the coach as things can go south in a hurry. If I ever have to do extensive work like he did, I will give him a call to make sure I don't miss anything before starting.
Pierce
Title: Re: Working under Unihome
Post by: stump on May 11, 2017, 08:29:57 pm
I am pretty sure you have a UniCoach and Not a UniHome. 8)
Title: Re: Working under Unihome
Post by: Realmccoy on May 13, 2017, 01:43:09 pm
Unicoach is correct. My bad.
Title: Re: Working under Unihome
Post by: Kemahjohn on May 14, 2017, 10:16:58 pm
Another option is to cut 11 1/2" pieces of 4x4" post. It cost almost nothing and will have very high compression load capability. I have used them several times with good success.