Possible to straighten out bowed aluminum extrusion?

[festal]

So it seems that the fence that came with my kity 637 jointer/planer has a bow in it. Is it possible to straighten it out?

Bow starts at the green mark

Sent from my iPhone using Tapatalk

 

[Bob D.]

How long is that piece about 24 inches maybe a tad longer.

 

[festal]

How long is that piece about 24 inches maybe a tad longer.

Spot on. Little over 23.5” by 6”

Sent from my iPhone using Tapatalk

 

[Crazyraceguy]

It is possible, but there is some level of risk involved. If you over bend it, trying to straighten it out, it is likely destroyed. It will not bend back without damage/breaking.

 

[Lincoln]

Try attaching a sub-fence/face to it - ply or MDF. Might be enough to straighten it, if not you can use packers between the fence/sub fence.
My cast jointer fence had a slight bow to it, so drilled some clearance holes through it and attached a piece of 25mm Birch ply. Few pieces of blue tape here and there for packing and it's now dead straight/flat.

 

[rvieceli]

I'm going to suggest either just ignore it and remember to reference of the bottom 2/3 of the fence OR attach another face to the current fence and shim it flat. I used a piece of UHMW plastic for my table saw and the folks I bought my band saw from used a piece of hard maple.

On the subject of shims, grab a couple of those cheap import feeler gauge sets from your favorite vendor. They are usually around $5 or less and use them with CA glue or tape.
https://www.harborfreight.com/feeler-gauge-32-pc-63665.html

Ron

 

[Bob D.]

Are the two t-slots what is used to secure it to the machine.
Is the bow consistent for the whole length.
Can you show in some photos where this mounts on the machine.

 

[festal]

Are the two t-slots what is used to secure it to the machine.
Is the bow consistent for the whole length.
Can you show in some photos where this mounts on the machine.

Yep now spans entire length. There are 4 t-slot bolts on the back. Picture only shows 2

Sent from my iPhone using Tapatalk

 

[festal]

I'm going to suggest either just ignore it and remember to reference of the bottom 2/3 of the fence OR attach another face to the current fence and shim it flat. I used a piece of UHMW plastic for my table saw and the folks I bought my band saw from used a piece of hard maple.

On the subject of shims, grab a couple of those cheap import feeler gauge sets from your favorite vendor. They are usually around $5 or less and use them with CA glue or tape.
https://www.harborfreight.com/feeler-gauge-32-pc-63665.html

Ron

That might be a way to go. I did order uhmw tape from Amazon and was going to tape it on top and wood would glide over it. 5mil tape so hopefully that would be enough

Sent from my iPhone using Tapatalk

 

[Bob D.]

Is there a gap at this point between the t-slots?

With the fence off are the faces of those mounting brackets that meet up with the fence flat.

 

[festal]

Is there a gap at this point between the t-slots?

With the fence off are the faces of those mounting brackets that meet up with the fence flat.

There is a gap where you have an arrow.  0.80mm feeler gauge fits in there.  I'll check the faces of the mounting brackets a bit later today. need to remove the fence

 

[jeh]

Not to hijack, but how does that safety arm work?

 

[festal]

Not to hijack, but how does that safety arm work?

Blade guard?  it does.  Its European style vs porkchop style

 

[chrisrosenb]

I straightened the aluminum fence on my 16" jointer by screwing a piece of hard maple to it. I then ran the face of the fence over the jointer to straighten it. It has worked great for the past 11+ years.

 

[FestitaMakool]

If you have a heat gun..
Have you tried to clamp it down (with all steel clamps…) face down on a flat surface, heating it slowly in the area where the bend is - while slowly tightening the clamps until it’s laying flat and give it the most heat then? Then leave it until cooled.

 

[mino]

That whole assembly looks wonky. Starting with the fence connection and ending with the fence not looking very sturdy to begin even if was straight.

As a (cheap) bet I would go with the "attach some hardwood to it which you make flat".

A proper solution would be to scrap the whole fence and design (have) a new one (made) which would have its face machined including the way the fence attaches to make it more sturdy, playing also with the pivot point while at it so it has zero give.

You can use a standard extrusion like 30x120 mm or whatever is locally avaliable. Just with one face machined to be trully flat.

The last -most obvious- option is to have the bent fence machined WITHOUT trying to flaten it by force. When aluminum alloyws bend, there are permanet changes in the structure. Trying to bent it back will weaken it and even if it does not break the already-wonky fence would become even weaker.

 

[Peter Kelly]

I straightened the aluminum fence on my 16" jointer by screwing a piece of hard maple to it. I then ran the face of the fence over the jointer to straighten it. It has worked great for the past 11+ years.

I love that blade guard, need to fab up something similar for my jointer.

 

[festal]

That whole assembly looks wonky. Starting with the fence connection and ending with the fence not looking very sturdy to begin even if was straight.

As a (cheap) bet I would go with the "attach some hardwood to it which you make flat".

A proper solution would be to scrap the whole fence and design (have) a new one (made) which would have its face machined including the way the fence attaches to make it more sturdy, playing also with the pivot point while at it so it has zero give.

You can use a standard extrusion like 30x120 mm or whatever is locally avaliable. Just with one face machined to be trully flat.

The last -most obvious- option is to have the bent fence machined WITHOUT trying to flaten it by force. When aluminum alloyws bend, there are permanet changes in the structure. Trying to bent it back will weaken it and even if it does not break the already-wonky fence would become even weaker.

It is wonky.  Having it machined is an option but not cheap around me.  Not worth it.  I actually ended up selling it and went back to my 6" ridgid for now.  Will look for something else once it becomes available.

 

[Cheese]

When aluminum alloyws bend, there are permanet changes in the structure. Trying to bent it back will weaken it and even if it does not break the already-wonky fence would become even weaker.

What mino said...aluminum doesn't like to be bent and then re-bent, it just isn't very happy.  [smile]  It's just not a very ductile metal compared to steel or copper. It work hardens easily which is similar to SST and once bent and then re-bent it likes to fracture. You can certainly try to rebend the fence as you have nothing to lose but just be aware of the likely possible outcome.

The suggestions of attaching a wood face to the fence and then machining that surface makes the most sense to me, short of designing and constructing your own fence from other extruded aluminum products.

 

[festal]

When aluminum alloyws bend, there are permanet changes in the structure. Trying to bent it back will weaken it and even if it does not break the already-wonky fence would become even weaker.

What mino said...aluminum doesn't like to be bent and then re-bent, it just isn't very happy.  [smile]  It's just not a very ductile metal compared to steel or copper. It work hardens easily which is similar to SST and once bent and then re-bent it likes to fracture. You can certainly try to rebend the fence as you have nothing to lose but just be aware of the likely possible outcome.

The suggestions of attaching a wood face to the fence and then machining that surface makes the most sense to me, short of designing and constructing your own fence from other extruded aluminum products.

I'll let the buyer deal with it lol.  back to searching for something else