Hammer N4400 Fence broke :(

[joez]

Hi All,

I tried locking down my fence and a piece seems to have broken off. The Bandsaw is a couple of years old but I dont think I have used the fence a dozen times as you can see in the pictures the fenced is pretty much unused.

I have send an email to Felder to find out about obtaining a replacement, can anyone tell me if this is fixable? or should I just buy a replacement.


Thanks
Joez

[GarethR]

Sorry to hear your fence broke Joez. Is that cast iron? Doesn't look like a weak point, or near a join. Judging from the limited use and using you haven't been doing something crazy with the fence I say it looks like a bum fence.

Could you perhaps fix it by using some metal friendly epoxy (http://www.jbweld.com/products/surface-applications/metal/)?

I'm expecting my N4400 sometime this month so hopefully this is not a common problem.

[joez]

Sorry to hear your fence broke Joez. Is that cast iron? Doesn't look like a weak point, or near a join. Judging from the limited use and using you haven't been doing something crazy with the fence I say it looks like a bum fence.

Could you perhaps fix it by using some metal friendly epoxy (http://www.jbweld.com/products/surface-applications/metal/)?

I'm expecting my N4400 sometime this month so hopefully this is not a common problem.


The portion that broke is about 10mm square, the casting doesnt appear to be magnetic so I dont think its cast iron, not really sure.

[elanjacobs]

Try posting in the metalwork forum, you might find someone there who can help.

[pjt]

Hi Joez, I'm pretty sure that fence part will be cast iron, it is fixable but the work and cost to do so might be even more than a new one unless you know someone that can weld cast and then clean up the weld back to the existing machined surface so it runs on the bar, maybe take it into the local engineering shop and get them to give you a price to fix.

In the second pic there appears to be an area of slightly duller appearance on broken face, to an expert eye things like this indicate there may have been a crack to the depth of that line, might be worth pursing, I stress that I am only seeing this in the pic and it may be nothing.


Pete

[Wongo]

I hope they give you a replacement for free. The fence is supposed to be strong enough for normal wear and tear and more so for a good brand like Hammer.

Good luck.

[Kidbee]

Maybe it got a bump in the shipping process that weakened it.

[bosox]

That's so bad! I have no advice at this time. Hope you'll get a replacement of your band saw fence.

[cow]

Hi Joez,

Speaking as an engineer and not any kid of expert on bandsaws, that is a high stress area and any defect in the casting will make things worse by acting as a stress raiser. It looks like there is a difference in the fracture face on the bottom left of the second photo and that looks like the failure initiation point. It's about the point of maximum tensile stress where you'd expect a casting to let go and I'd expect it to be designed to cope with maximum stresses you'd expect to see in service. I'd be looking for a replacement from Hammer. If you didn't subject it to unreasonable loads then either the design is weak or more likely there was a material defect.

A welding fix would be possible but expensive, complicated by warping and re-machining and you'd never feel the same about it. You could glue then drill and pin it maybe but honestly if Hammer don't do right by you then I would be looking for an aftermarket fence. Or maybe someone who already replaced theirs would sell you their original?

Cheers
Cow

[hiroller]

I think Hammer should come to the party.

If not you can "stitch and glue" it back together.
Drill a small hole (say 2mm) in the side of each piece.
Each hole should be about the thickness of the piece away from the broken face.
Use epoxy glue. Epoxy likes a bit of space, so first rill a few shallow holes in each face.
Glue it up and thread some wire through the holes, join them to make a loop.
Cut the wire and twist tight with a pair of pliers.
Wont be as beautiful - but will hold for years.

[joez]

Hi All,

I have just heard back from Felder/Hammer they are replacing it free of charge even though the Bandsaw was purchased in 2008. :D

Great service from Felder, couldn't have asked for more.

thanks
joez

[Wongo]

Hang on you said your bs is a couple of years old. 2008 is a bit more than a couple of years don't you think? :;

Good outcome. And good work Hammer (if you are reading), you have done the right thing.

[joez]

Hang on you said your bs is a couple of years old. 2008 is a bit more than a couple of years don't you think? :;

Good outcome. And good work Hammer (if you are reading), you have done the right thing.


I was shocked when they said 2008 too, I could have sworn it was around 2010/2011, purchased a dust collector from them a later on I must have my dates mixed up.

[zelk]

Sadly, I have had the same problem. One claw broke off and then the other. The broken part of the component seems a little under-engineered. The fence was not mistreated and the bandsaw was not used much.

When clamping the fence, most of the pressure is on these claw bits which maintain the fence alignment to the rail ( 30mm round bar) The part is about $140 delivered, which seems reasonable.

Before buying a new component, has anybody repaired one successfully. I feel that a new component could have the same fate.
Zelk

[GarethR]

I'm somewhat surprised that the fence is breaking. Either it's a defect or the fence is undergoing undue stress.

My original suggestion was to to use some epoxy (http://www.jbweld.com/collections/metal)and if it was me that's what I'd do first up.

[zelk]

I'm somewhat surprised that the fence is breaking. Either it's a defect or the fence is undergoing undue stress.

My original suggestion was to to use some epoxy (http://www.jbweld.com/collections/metal)and if it was me that's what I'd do first up.

As mentioned, one claw broke off a while back, unfortunately I cannot find it now. It might have to be a fix using a different method. The two claws are the weakest points that require the greatest strength in the assembly.

[Dovetail]

Mine broke in exactly the same position some time ago but unfortunately, Felder did not come to the party. Suggested I had overtightened the fence when setting - which I hadn't as far as I could remember.

I had mine welded. I think it cost about $10. I've used it many, many time since with no issues.

Very likely a design or casting fault

[zelk]

Mine broke in exactly the same position some time ago but unfortunately, Felder did not come to the party. Suggested I had overtightened the fence when setting - which I hadn't as far as I could remember.

I had mine welded. I think it cost about $10. I've used it many, many time since with no issues.

Very likely a design or casting fault

I had the same response from Felder, they said that I may have dropped it. There are clearly a number of forumites who have had the same problem, it is unlikely that everyone had dropped theirs.

In your case, did they weld entirely around the break or only a part?

As I have lost one of the claws, I am working on a clamping method. If it works, I will post the details.

[Dovetail]

They welded entirely around the break then ground away the swarf in the hollow section so that it didn't foul the guide rail.

[zelk]

The prototype.
408472408473408471408474408475408476408477408478408479408480

[Dovetail]

Hi Zelk,


I applaud your determination in making a 'different' clamping arrangement for your N4400 fence.
I've come up with a different idea which I would likely employ should my fence ever break again.

If this works, you won't need to fiddle with spacers and clamps every time you want to use your machine. I've just used roof/wall bracing material for demonstration purposes and a more robust material would be needed in an attempted repair. I should think something malleable like 3mm aluminium bar for instance. Or some mild steel if you can form it. The factory clamp tightening lever can really apply an enormous load on the clamp lugs which I don't believe is necessary and could account for SOME breakages.

The first images shows (roughly) the idea side on. The material is attached to the outside of the clamp bracket which is quite thin and could be drilled easily IMO. A couple of small bolts will secure the new bracket.

408885

The second image shows the arrangement from below. Again just a rough demonstration -- the material would need to be formed more accurately.
408886


The third image demonstrates the 'strap' on the outside of the main bracket with an indication where one of two mounting bolts could be fitted.


408884

The lug that was welded can be seen in the first two shots. Looks a bit rough but works well enough.

Cheers

Brian

[zelk]

Hi Brian,
is the formed metal strip designed to maintain a clamping force, ie, bracket to bar and would you still use the original locking handle?
Zelk

[Dovetail]

Hi Zelk,

Yes, if you use a metal of some strength and form it to fit around the bar, then I see no problem attaining sufficient clamping pressure. I would think two metal strips should be used - one on either side of the locking handle. You could still use the original locking handle but I'm of the opinion that by the very nature of its design, the leverage one can apply is tremendous and I suspect those folk who have broken lugs directly, may have done so by overtightening. Perhaps one could use a different locking system like a threaded knob or at least be aware of the force being applied.

After fitting the metal strip/s, you may have to realign the fence to get it square but that's no big deal.

Cheers

Brian

[zelk]

Sounds like you would be creating a similar set up to the original one.

The 'round bar to table' connection points ( as shown in my last picture ) are a nuisance as they can interfere with the 'fence bracket to round bar' clamping. The original fence bracket design was compromised for the sake of them, nevertheless, they could have been made stronger so that overtightening is never an issue.

[Dovetail]

Yep, very similar but I don't see why they wouldn't work as long as they are kept shy of those pesky connectors. Also, because you could make them broader, there will be more surface area to contact the round bar.

[zelk]

"Pesky" is a good description. With my prototype I can relocate the clamping so that the connectors do not interfere, regardless of where the fence is positioned on the table. It is always better to clamp either at the middle of the bracket, where the tightening screw use to be or to the left of it. If one clamps to the right of middle, then the end of the fence can, with some force, be pushed away from the blade and there would be need for some support behind the end of the fence using magnetic stops or some clamping as mentioned before. Overall, the prototype works efficiently. With favorable center of gravity, the front lip at the bracket supports the clamp and adjustment is quick.

[woodPixel]

One could buy a new Drift Master Fence. They are universal: https://www.gregmach.com/product/drift-master-fence-system/

If the metal you are trying to fix is non-magnetic, try brazing it first. Its something you can do yourself at home with a little torch (Supercheap, Bunnings, etc) and rod from a welding shop. Its not atomic-level strong, but it will certainly be stronger than the "metal"* they seem to be made of. Example: https://youtu.be/-oifC7fbQfY

Its pretty easy, will be smooth and can be painted over with spray can.


* pots, pans and cutlery round up day for the furnace perhaps?

[zelk]

One could buy a new Drift Master Fence. They are universal: https://www.gregmach.com/product/drift-master-fence-system/

If the metal you are trying to fix is non-magnetic, try brazing it first. Its something you can do yourself at home with a little torch (Supercheap, Bunnings, etc) and rod from a welding shop. Its not atomic-level strong, but it will certainly be stronger than the "metal"* they seem to be made of. Example: https://youtu.be/-oifC7fbQfY

Its pretty easy, will be smooth and can be painted over with spray can.


* pots, pans and cutlery round up day for the furnace perhaps?

I like that fence, I wonder how much freeplay there is in the gearing.
The drift adjustment has given me an idea. With my prototype, if I reintroduce the original screw for tightening, I could possibly use it to offset the fence alignment, thereby, adjusting for drift.

[woodPixel]

Zelk, drift is fixed at the upper wheel, not the table: https://youtu.be/wGbZqWac0jU


On the Drift Master, I have one. It works very much like an incra fence, but FAR less refined.

I've written to Incra and suggested it as a product a couple of times, with suggestions, but one never hears back from them - ever, on anything, even once. I wish Incra were better at customer service.

I reviewed the DMF fence somewhere here a long time ago. It is OK for the money, but not spectacular. It is certainly an easy thing to drop money onto to solve a problem.

My thoughts would be:

-- Making a simple one wouldn't be too hard, a DIY job something like these https://youtu.be/peEARS5rr1Y or https://youtu.be/4pudkvHFOfk
-- The Drift Master Fence is universal for pretty much all bandsaws
-- The DMF is flogged as a Laguna product, but it isnt. It is clearly fabricated elsewhere using vastly different quality controls (i.e. inferior to the Laguna)
-- There are HEAPS of improvements that could be made to the Drift Master Fence. I am rather surprised (disappointed) that they haven't a new version yet.

If I had a metal shop, Id make a really slick one without hesitation.

[zelk]

The DMF claims to be adjustable for drift, in a similar way to this Youtube clip https://www.youtube.com/watch?v=IZThUPOr_Ug

[woodPixel]

Yes, but its the wrong thing to do. Drift is fixed at the upper wheel.

Adjusting for drift at the table is like giving your car a wheel alignment by taking of and moving the steering wheel. If *works* but its not how its done.

After watching the snodgrass video enlightenment will occur. :)

The DMF is just like the incra fence, it is fantastic for moving the fence in a very fine and controlled manner. Underneath the main body is a quick-move release as well as a lock-lever. These are good for when you have it just right. :)

409011

[zelk]

I do not disagree, I was merely pointing out that I could possibly modify my prototype to correct for drift like the DMF.

I gather that one would have to change the correction for drift when changing blade and timber characteristics.

[Pearo]

You can add me to the list of people with broken fences now as well. Last night I went to use the bandsaw, moved the fence to the back and I heard something drop to the floor. thought it was a bit of crap I left on the table. Went to lock in the fence and sure enough, its broken in the exact same place as the other photo's. Have contacted the local rep to see if there is an upgraded or better fence for it, because I am not going to replace it with the same faulty fence if I have to pay for it.

Going to use the opportunity to upgrade to the ceramic guides as well.

[Dovetail]

Well, Pearo I must tell you that my welded repair of the fence clamp continues to hold despite a great deal of use.

I'm disappointed that Felder Australia hasn't come to the party on this one. Surely we are not all over-tightening the clamp or dropping it onto a hard surface with any regularity?

[Pearo]

Well, Pearo I must tell you that my welded repair of the fence clamp continues to hold despite a great deal of use.

I'm disappointed that Felder Australia hasn't come to the party on this one. Surely we are not all over-tightening the clamp or dropping it onto a hard surface with any regularity?

Mine certainly was not dropped. I just moved it on the saw table.

I have not sat down and had a good look at it yet, but given I am learning fusion 360 right now it may be a good time to design a new one from steel if there is no alternatives. My father just bought another milling machine and is going to make it into a CNC, so maybe 6 months from now I can machine a new fence out of a block of solid steel!

[derekcohen]

I have had my N4400 for about 7 years now. For the first couple of years I was disappointed with the movement in the fence. It was sloppy when moving into position. It turned out that the wrap-around slide was machined with poor tolerance, and this section was loose. I was tempted - well, I would have liked to - drill and set in a couple of set screws, but on inspection, the metal was too fragile. It looked like cast aluminium or cast iron. I think the latter. Drilling it out would have been a recipe for fracture. In the end, Felder in Perth replaced the base. It has worked smoothly and accurately since.

I am puzzled by the use of cast iron this design. It really is not appropriate, just too fragile with the thing "fingers" that create the support around the bar guide. I would love someone to offer an aftermarket replacement in aircraft aluminium, and tapped for set screws (if adjustment is ever needed).

Regards from Perth

Derek

[Pearo]

Felder has come to the party for me ( thankfully, given the money I have spent on their machines). I don't think they believe me when I said I was just moving the fence on the table, but that's how it happened. Anyway, when the new one arrives, I will draw it up in fusion 360 then do a 3 print for a test fit. Once we get the old mans CNC Mill finished I will make one from steel or aluminium with much more meat on the fingers.

If anyone has any suggestions on how to improve on it let me know. When I finish the design I'll publish it and the g-code somewhere so anyone can make one.

[Pearo]

New part turned up. Complete different casting, so Felder are obviously aware there was an issue. I'll post some pics up later tonight, but the fingers are a few mm thicker, and the casting is a lot more solid in the back.

I'll get cracking on drawing it up. Might be a bit tricky to machine, but I'll cross that bridge when I come to it.

[Pearo]

Here is the pics

[Pat]

Substantially thicker. I might have to check mine, just for interest sake.

[Pearo]

Righteo, so I pulled my finger up and have modelled the N4400 fence in Fusion 360. I'll embed the image at the bottom so I can leave it at high res.

At this stage, its solid. Here is the dilema, if I make this from steel, its going to weight a lot. How much I am not sure, but without calculating it its pretty obvious that its going to be several kg. The original cast iron part is about 2.5kg, so I would guess a solid steel unit would be better than 5kg. Best part about that is you wont break it.

Alternatively, its also possible to machine it out of aluminum. I cant see there being any strength issues if its kept solid, and it will be easier to machine. The downside is I reckon a piece of billet aluminium that side would set you back some where up near $100.

I am undecided at this stage about which way to go. There is also another option and that is to remove some excess material from the guts of it. Decisions, decisions...

Anyway, let me know what you guys think. I'll start a prototype going on the 3d printer to see if there is any issues with it so far. We are still building the CNC mill, so I cant see me actually turning out a steel/aluminium part this year. Still, its a start in the right direction.

https://i.imgur.com/DcllK1S.png

[joez]

Righteo, so I pulled my finger up and have modelled the N4400 fence in Fusion 360. I'll embed the image at the bottom so I can leave it at high res.

At this stage, its solid. Here is the dilema, if I make this from steel, its going to weight a lot. How much I am not sure, but without calculating it its pretty obvious that its going to be several kg. The original cast iron part is about 2.5kg, so I would guess a solid steel unit would be better than 5kg. Best part about that is you wont break it.

Alternatively, its also possible to machine it out of aluminum. I cant see there being any strength issues if its kept solid, and it will be easier to machine. The downside is I reckon a piece of billet aluminium that side would set you back some where up near $100.

I am undecided at this stage about which way to go. There is also another option and that is to remove some excess material from the guts of it. Decisions, decisions...

Anyway, let me know what you guys think. I'll start a prototype going on the 3d printer to see if there is any issues with it so far. We are still building the CNC mill, so I cant see me actually turning out a steel/aluminium part this year. Still, its a start in the right direction.



That looks x10 better than the original!

I wonder is its possible to mount the fence from its base rather than its side, if so you'd be able to lob the top 1/3 off your mount.

Check out the Laguna rip fence, it probably makes more sense than I am :) https://www.lagunatools.ca/accessories/bandsaw-accessories/bandsaw-fences/rip-fence-assembly/

[uzzi]

Hey Guys,

Just a thought....why not make a set of doubler plates (with matching 'fingers') and then bolting them to each side of the mount, seeing that they are pretty flat. Plate aluminium (3-4 mm thickness) should be plenty strong.

Cheers
Chris