Technical Why do armrest screws angle up?

I have no door pulls or armrests on my ‘54 dodge pickup. I just finished making luaon cards that are getting covered in black diamond pleated marine vinyl and I’m also making armrests/door pulls. It’ll be nice to have someplace to set my elbow but even better to have someplace to grab the door. Despite a couple afternoons spent improving the door fit it still needs a gentle lift and a snappy pull in order to latch.

I have the armrests mostly made. I just have to figure out the angle of the screws. I’m using the stock stamping in the door that has holes to use 1/4”-24 clip in nuts.

All the armrests I’ve taken off old cars had screws that angle up. Anybody know why? It seems like that would help them stay tight against elbow weight pulling down but I anticipate more force pulling in and up?

All I gotta do to finish these is figure out how to make the angled screw heads hit flush- maybe a drilled wedge of ironwood to match the pad? Or a metal solution welded in? Or a piece of tubing cut at angles and tigged on?

My fine thread wide panhead screws should be coming from McMaster today and I have some time tomorrow to work on them- any suggestions are welcome!

Here’s my sketches and what I got done so far. Changed a little. The ipe/ironwood matches my parking brake handle and bed wood. I’m going for a hotrod look but might be veering into ‘70s RV cup/map holder territory with the woodwork

 

Being angled up, makes it so you won't be as likely to see the unsightly screw heads.

 

Also less likely to drill a hole in your window glass.

.bjb

 

Also puts the screw in tension rather than a bending moment when pressure is applied from verticle.

 

Not really. They are only a coupla/few degrees, not enough to miss any glass if you drill too deep.

Again, not really..! A screw at about a 5° or 6° angle is NOT really in tension..! It's still in shear (or bending as you call it).

Mike

 

As to support weight.....

 

My thoughts exactly.

Think about it, if the screws were attached straight in it would be logical if using the arm rest to pull the door shut the non angled screws would eventually loosen up and pull out, the angle just gives the screws a better chance of staying tight.

When I was removing the arm rest on the Ranch Wagon they were very tight and after almost 5 decades the screws put up a fight taking them out, verses some of the straight screws holding trim which had no resistance at all. HRP

 

That was far too easy...………………..Lord I am good.

 

If a screw is tight, no matter the angle, isn't it in tension?

 

More contact area or thread engagement so to speak, the same reason for using fine threads on thinner sections of stock.

 

Because that is the way factory design engineers came up with . Mike should not be able to say , "Again, not really..!".

 

They're screwed up

 

Ha!

 

So why are turds always tapered?? So your butt hole don't slam shut....

 

Good spot for nutserts.

 

Welp I guess the angle is helpful for keeping the screws tight under constant elbow pressure. My truck has clip on nuts so it’s not a thread engagement in sheetmetal issue.

I am thinking little angled chunks of tube tigged to the base will be the best easiest and wood wedges with countersunk holes would be the cleanest.

I like the hamb because lots of responses always come fast- part of that is all the smart-assery which ia fun too. I guess since it went straight to potty jokes instead of making fun of my armrests they must not be too ugly or wierd looking!

Thanks all for the input

 

Hey, those engineers get payed Big bucks to get this shit Right! Well.............most of the time.

 

Having worked on my daughters VW van last night, there is an overpaid German out there somewhere.

 

Don't over think it. Just copy what the factory did.

Sent from my SM-T350 using The H.A.M.B. mobile app

 

Farfegnugen!

 

Billy, they just worry about the design aspect (on paper). The Techs (or us) are the ones that have to deal with the result (in real life)!

 

Yep, the angle causes your elbow weight to create additional tension, instead of a bending force.

All ones I recall working on are at a near 30 or 40 degree angle, not the 5 or 6 I saw in another post.

 

Think VW is bad....ever work on a Renault? Cheapest crap I ever saw.

 

LeCar is LeCrap Nes pa?

 

The angle of the head of the screw is set so the head is flat with the curved bottom of the arm rest.

 

Just to make it harder to get the screws started. Some engineer got a good laugh out of it I bet.

 

Here in Oz the guys at T J Richards who were the Oz mopar body builderswelded a piece of 3/16th plate onto the door shell where the armrest lives, drilled and tapped 2 1/4" UNC holes and the brackets that hold the armrest against the door are slotted so the armrest can be adjusted forward and back about 1&1/2 inches then you just tighten the screws against the door card...........the screws have a large molded on plastic head so they can easily be turned & tightened by hand...........this is the only pic I can find that you can just make out the plastic headed screws......andyd

 

I got the armrests done- ended up making 30° angled washers/spacers out of 3/4” round stock.