how to build NICE model a door hinges for cheap

so you picked up an old jalopy thats been beat or your slammin together some old whooped body with the cowl you found on ebay and you realize you aint got a good nice set of factory door hinges. so what do you do? you can call up MACS and charge a set of bronze casted hinges that will prolly cost more than you got invested into your entire sheetmetal pile (not to mention still need all the drilling), or you can jump back on ebay and pay like $50 a piece for a set that are clapped out as bad as the ones you got or try wrestling everybody in the classifieds section for the first shot at whatever ones show up...

or... you can make them.

thats if you got some scrap 3/16 plate a few handtools, some bolts a few factory hinge pieces to copy and a buddy with a lathe

these are the hinges i started with. they have holes rotted THROUGH them.




this post could get a bit long so chill out while i post the pics and info please

 

first thing i did was take apart what was left of the stock hinge pieces and drill the pin holes out to 1/4"

i did this because 1/4" is much more common than the stock pin size and will make assembly and setup of the "jig" alot quicker and easyer

 

then i grabbed some scrap 3/16" plate (i used cold rolled but hot rolled would work)

and traced JUST the ends of the stock hinge roughly and transfer punched the hole center and drilled those holes to 1/4"




you can see how the look traced out on the steel, all you need here is the end "tab" as i call it

 

myself, i used a vertical bandsaw to cut these out after they were drilled, the same could be acomplished with a sawzall, airsaw or cuttin wheel with a lil time and patience

dont be afraid to cut them a bit large ot rough cause they will need to be sanded and fit later




then to make things nice i took a step drill and used it to put a slight chamfer on the 1/4" hole, then used a 1/4" bolt and nut with a few washers to bolt the two pieces together and lined them up nice to them outer edges could be sanded together and both would recieve the same exact outer profile.

 

the washers were used for two reasons, it keeps the hole of the tab onto the shoulder of the bolt to help ensure that both pieces stay lined up in relation to the center of the hole, and it gives you room to clamp onto





a belt sander really helps in this pricess but a disk grinder works just as good





now they are all smooth. set em aside and your ready to start the next step

 

I'm chillin'.....

 

Dont stop now, where is the rest of it???

 

grab the stock hinge piece that you copied the tabs from and make a quick cardboard template of the outer edge, use the outer side because then the steel you cut when your pattern is transfered will definately be too long and will allow you to trim later. myself, i traced the holes and everything. stock model a hinges have plates that are roughtly 1 5/8" wide i believe, so tracing isnt necessary for that dimension if your stock hinges are really rough.

mark on the cardboard roughly where the tabs start and subtract 3/16" from each side and project that to the edge that wraps.


you can see in the pic that i have a few extra holes marked, thats because i used the same pattern for my upper and lower door hinges, i just added hole marks as need be.



your pattern should look like this, trace it onto some steel and centerpunch the holes





once again i drilled the holes first, you dont have to if youd rather save that step for when they are together and your ready to mount them to the doors or cowl, but i went ahead anyways.

just make sure you drill them to whatever size you want so that you can tap them if need be.



i cut them out on a bandsaw, but a sawzall, chopsaw, cuttin wheel, etc would work fine.

 

Excellent tech so far---Brian

 

now heres the part that might tweek some people out. we gotta make a "jig"

grab that same stock hinge piece and dig up some DOM, dowel rod, or whever is steel and cylindrical that has the same outer diameter as the inner diameter as the factory hinge, myself, i just ran around the shop trying different scrap pieces till i found something that worked, i think it was 7/8"

cut it so it fits inside like this



and weld it to a decent piece of steel tubing so it looks like this...



i used 1"x1" tubing, seemed to be real nice. make sure you weld it good.

now take your stock hinge and set this contraption inside it so you can trace where the end of the plate lands on the square tubing and i also marked the front most hinge hole for reference


so i looks like this


if you really wanna get crafty grab some dowel that fits inside the mounting holes you drilled on your new piece of steel and drill your box tubing and press that into the tubing so you can set up new hingeplate perfect,

myself i wanted to keep the tool universal so i did some fandangling here.

the next step is to align your new hing plate with the marks you put into your "jig" and carefully (if you opted not to dowel it) clamp it in a vise with the DOM exposed

 

to make this easyer on myself i used a rosebud on the torch, heat the end up and bang it with a hammer to bend the steel around the DOM



i hit it alot, but thats cool, youll grind it up later

this is where i stop


like i said, you may have to get out the grinder and clean up the edges a bit, but no big deal

 

now its time to find your buddy with the lathe, if you real skilled you can prolly get this done without a lathe, but its just alot easyer with a lathe,

we gotta start on the other hinge half now. myself, i used some 5/8" drill rod i found laying around the shop on the last set of hinges i made, it was really nice to work with, easy to machine and smooth, but i know some of you might not have that available,

so this time i used an old 1/2" bolt, grade 5 to keep the cost down. cut the head off and chuck the rest in the lathe.





i faced it real quick, then center drilled it and then drilled as deep as i dared with a 1/4" bit



take it back out and myself, i was in a hurry so i just lined it up with the factory hinge half and made a quick mark



sawzalled it off a bit long



grabbed the veirniers (sp) and measured the stock piece and used that measurement to machine the rest off in the lathe so the new piece was the right size.

 

That's actually a dial caliper, not a vernier, but good work so far on the hinges! I'm sitting at the office waiting to see the end of this before going home.

 

Keep it coming! Awesome!!!

 

Where is the rest of the story??

 

take that piece and chamfer the edges a bit,

 

sorry guys this ones taking a while, long posts and lotsa pics keeps kickin me off the hamb

but anyways, go back to the piece you bent, and now we gotta trim it because like i mentioned earlyer the cardboard pattern you made was on the outside and made you new piece extra long

compare it to a stock piece and make a mark on each side, then i just cut it off with a sawzall and grind it up a bit to make it nice.

 

your gonna want a nice smooth flat benchtop, piece of steel, or table of some sort for this next step. myself, i used the jumpshear at work, no big deal,

your gonna want to take your stock hinge you traced and measure from the edge to the center hole



then transfer those measurements from the edge of your table, bench, etc... outwards in two spots about 12" from eachother and connect those marks with a straight line.





this is where its best to have at least two factory hinge halfs to make it easy on yourself, if you dont you can make a piece with a 1/4" hole that was drilled at the correct dimension away from the edge as a stock hinge, but myself i used what i had, and mine are far from nice, but the new one still came out plenty nice enough to make me happy.

take the piece you made and the stock hingeplate and set them on the table so that the edge lines up with the tables edge and the center hole should fall on the line you drew



dont worry if its a bit off, the tolerances here are pretty forgiving

take another hinge and set it on the other side of your new piece,

 

now your gonna wanna grab some 1/4" rod, or something nice and straight with a 1/4" diameter, myself i used the transfer punch i had earlyer and it worked fine cause luckily no gorrilla came along and bent the shit outa it with mad hammering

grab your "tabs" and the piece you just machined up on the lathe and set them up like this



then carefully slide the two factory hinge pieces onto the end of the 1/4" rod so they look like this


its damn near impossible to do this step without bumping the pieces around a bit so dont worry, just keep checking your edges and center holes on the line you drew, make sure they are close. when you get this all lined up you can clamp them down if your worried about them moving.



then i took the tig welder and tacked the tabs to the bent piece quick, you can weld them with whatever you like, i just had the tig handy, and using it i had less of a chance of bumping stuff when tacking.

 

looking good so far

 

so now you can real carefully take apart this setup and you should have this


i took a quick 1/4" bolt and bolted the lathed piece in to keep it from moving. tacks are weak. especially when you get pissed and launch it across the shop. (no one here would ever do that)


i then went to the mig welder and just welded the hell outa them, fill the corner in good to give you some steel to grind and shape.



grind em down and keep the disk moving good to get a nice smooth shape.

 

Love it, great job

 

were getting closer now. the last piece to make. remember that template you made earlyer?

grab the stock half of the hinge that bolts to the cowl and lay that template on it



mark where the "shoulders" are and where the plates bend is


and mark the holes if you would like, not necesarry just yet though as stated before.

now your gonna trace that onto some 3/16" plate



make sure to mark where the bend goes and the holes if you would like

i marked the holes bu using the stock piece as a template



this is what i got



bandsaw again, you know...

 

now heres how i put the bend in it, i used the shops brake, which stressed the hell outa it cause im bending 3/16" and its only supposed to bend 16 gauge, it worked but dont tell the boss.

i have bent 3/16" plate in a vice and a hammer and some heat before, so that also a possiblitly

 

now it just so happens on a model a closed car hinge (30-31) when both halfs are parallel they are aprox 3/16" away from eachother, or so i measured,

so i grabbed a scrap piece of 3/16" plate small enough to not get in the way



layed it ontop of my welded door half with the lathed piece bolted in



and then set my newly cut cowl half piece ontop of the pile and held it up to the lathe piece



and i noticed i had to trim a bit off the shoulders, but no big deal, then i tacked thr lathed piece and the cowl half together. you wanna make sure you keep the edges lined up nicely, because the holes arent drilled its not real crucial on the length, cause you can cut later when fitting them to the car, but i always try to keep it close on side to side, a clamp can be used to hold everything nice



tacked, then i took it to the mig and went nuts.

 

after everythings cooled off you can put it together with a 1/4" bolt, myself ive used them for hinge pins and had good luck, i run a really long stainless bolt so that the shoulder is what the hinge rides on and just cut the thread length down so it looks clean, grab a short nylock jamb style nut cause they are skinny and everything should be safe. you can sand the bolts head to a nice dome and polish it on a buffer quick and everyone usually thinks they are just hinge pins, but its nice when you dont have to hammer them out anymore

heres some pics before grinding




now i usually do some grinding on everything, smooth them up with like 80 then 120 paper and have a nice finished hinge.





what is, and what used to be...

 

nice work

 

now when you go to mount these new hinges to the car, you may have to tweak them a little bit to get the doors to shut perfect, its no big deal because on most model a hinges the cowl halfs have a really sharp jog in them right where they bolt on. it doesnt have to be this sharp and you can adjust the angle of your bends to compensate for door jap if need be.

the trick to mounting these and making it work nice is to grab a really long piece of 1/4" rod so that it sticks through all hinges on a side to keep the imaginary line of pivot perfectly straight between the two so they wont bind when you open the door.

thanks for checkin the topic everyone, thats all i have for now, good luck and let me know what you think.

Tech Week is rad.

 

Wow!! those look great!

 

Very Nice.