Hammer A3 feed roller question

[Susumu Mori]

I wonder if Hammer A3 users of this forum could give me some advises.

I bought A331 a year ago and it has been a smooth operator. However, the feed roller becomes a bit cranky these days. Often times, it is reluctant to receive a stock. It's not a big deal for surface plaining, but when the stock is standing on its edge, it sometimes dent the leading edge of the stock that meets the roller.

I suppose the spring of the roller gets too tight or the moving mechanism is gunked up but when it comes to the feed roller adjustment, the manual says, "contact service".

Have you experienced this symptom and if so could you adjust the machine?

thanks in advance.

[ian maybury]

Hi S, I have an A3 41 of the separate tables type. I've set the thicknessing table alignment and checked out the feed rollers, but haven't had to adjust the rollers yet. PM if a copy of the Hammer set up manual and parts drawing would help. It's less than comprehensive in this area (can't imagine why ) - but it specifies tolerances for the various alignments, and how to test them. You may find you want to adjust to rather tighter tolerances than are specified. (can't imagine why this might be either)

So far as i know set up isn't usually too complicated on these machines - but find your own way/go carefully/at your own risk.

First off check the toothed infeed and outfeed rolls for any build up of resin or compacted dust - this can mess with the feed. Brushing a light coat of (silicone free) wax on them reputedly helps avoid stuff sticking to them. The other basic check is for wear of the rollers - that they are cylindrical/don't have a hollow worn in. This latter seems unlikely. Probably no harm to check the feed roll drive belt, pulley condition and tension, and other drive parts and the feed control. No harm to block sand the thicknessing table down to 320 grit or better, and then wax it several times too. They can be grabby as delivered due to rough milling, and the temptation can be to jack up the feed roll spring tension to compensate. (which might if present contribute to your problem)

Presuming no issues in those areas, the next step might be to take a look at the thicknessing alignments and adjustments.

The basic assumption is that the rise and fall/thicknessing table is set so that it's parallel to the line of cut/the surface the knives generate in your work - presuming in the first place that the knife heights are correctly set in the cutter head, and that it's set horizontally in the chassis. (largely determined by the fabrication) The Hammer test for thicknesing table alignment is to pass two strips of squared timber ( say roughly 4x2in x 4ft long) through the thicknesser to clean both up - one to the far left side of the cutter, the other to the far right. Then lift the table by maybe 1/16in and repeat. Measure the thickness of the two pieces - they should be the same. Any difference will likely be the result of the table not being in the same plane as the cutter head. The fix is to adjust the side to side tilt of the thicknessing table using the four jacking screws at it's base. It's possible with care and lots of trial and error (the threads are pretty coarse) to set this to within a few thou.

Next up is to set the feed rollers. The end of each roller runs in a block welded to a stud which is located by the spring which applies the pressure required for grip and two nuts. Adjusting the lower nut (on each of the four studs) accessible through the slot in the inner face of the cabinet adjusts the spring tension. So far as i know there's an upper nut on the stud as well that adjusts the height of the roller relative to the circle of the cutter knives - this may well be be OK. Similar machines seem to set the rollers to something like maybe 40 thou below and accurately parallel to the cutter circle, but i've not seen a figure in the Hammer manual and this could be way off. Chances are if the machine was OK before/the upper nut hasn't moved that this adjustment is OK - it may just be that the spring tensions need adjusting via the lower nuts.

If the rollers are set too low, or the spring tension is too high the teeth may dig in and mark your work. If the opposite they may slip and struggle to feed thin work. If the spring tensions are too low at any of the four corners the overhung weight of the wood may lever the rollers upwards/allow the piece to droop as it starts or leaves the table - so that the cutter snipes the end. Snipe at the start suggests the infeed roll spring at the relevant side may be set too soft, at the end that outfeed roll spring(s) may be set to soft. (or just that it's a bloody huge baulk of timber that needed more support)

The basic test is to feed the two (square and identical height) strips through again as before, and observe whether or not they track straight, and whether there is any slipping or tooth marking. One or other strip turning/veering off to one side (anything but dead straight) suggests that the infeed or outfeed rollers may be tilted a bit out of the plane of the knives, and the top nuts may need adjusting. Not sure how it would work out, but i suspect it's best to get the top nuts/roller heights set accurately first (both rollers in the same plane, and parallel to and at the correct distance below the cutter) - and then set the spring tensions correctly. The spring tension seems to need to be set to strike a balance between avoiding slippage on thin stock, and not marking thicker stuff.

Maybe somebody else has the specified numbers for the roller height and nominal compressed length of the tension springs??

[Rod Sheridan]

Hi Susumu, as Ian indicated perform a visual inspection of the planer for compacted sawdust and resin stuck to the infeed roller.

Wax the planer table, this is very important.

The other issue is that the roller is designed to provide enough downward force to drive a 300mm wide board through the planer without issue.

Unfortunately that means that a narrower board has the same force applied to it, which results in much higher force/area which can crush a narrow board.

The other issue is depth of cut, try using no more than 1 or 2mm depth of cut on some hardwood, and then some softwood boards on edge, it may be depth of cut, area and wood softness.

Regards, Rod.

[David Wong]

As Rod said, waxing the table is very important. For me, waxing helped greatly reduce the sudden grab of the feed roller when feeding boards on edge.

[John Lankers]

Also, the feed table should get smoother over time all by itself. Your machine still has the 'new car smell'

[Susumu Mori]

Thank you all. They all make sense. You guys are really great.
I'll clean up the rollers and wax the table.
Also I understand the inherent issue of the heavy-duty planer for a narrow-edge planing. That really explains why my face planing is fine.

I have been without a table saw for more than a year. So, I don't have another way to dimension the width when exact width is needed (otherwise, I dimension by my bandsaw).
I'm one-click away from Hammer B3 and this could be another reason to push my back.

With a B3, I can dimension the width by the table saw or by the shaper with an outboard fence.

By the way Rod, can you attach an outboard fence to a slider shaper? Can you use the rip fence as an outboard fence?
Just curious how you set it up.

[Rod Sheridan]

Hi Susumu, I also almost always edge plane my material to finished dimension.

Yes you can attach an outboard fence to the sliding table or the other side of the spindle on the cast iron table.

My outboard fence is a length of aluminum channel that I clamp to the table..........Rod.

[Susumu Mori]

Hi all,

I just want to say thanks to all the suggestions.
I cleaned the roller and waxed the table.
It is amazing what a thin layer of wax does!

Now things go back to where it was a year ago.

Thanks,

Susumu

[Bill Berner]

I thought I would provide an update to this thread as I have had a feeding issue not related to the dirtiness of the table. When it first happened, I cleaned the table as directed and the unit continued to feed for a couple days but then "seized up" to the point that the infeed roller stops the second a piece of wood touches it. Felder believes part of the mechanism may be damaged, asked me to try and remove the nut at the end of the threaded rod that goes through the roller. Unfortunately the nut is stripped so I'm working on next step to either pull it or cut it off. I'd rather pull it off, as cutting I'm afraid will make it harder to root cause the original problem.

I do have a question for other forum posters though. As I've been thinking about, I'm wondering if the unit may have been defective since I received it, and slowly degraded to where it is now. The reason I ask is that even when it was new, if I tried to plane more than about 1.5mm from anything, the rollers would stop. That is far below the max that Felder documents (I think 3mm), but I figured the Felder number was just BS. Can anyone here verify an A3-31 should be able to plane at leat 2mm off relatively soft wood (say Sapele)?

I'll post back to the forum once I'm able to resolve this problem. I've been down many weeks already...

[Rod Sheridan]

The machine will plane the specified depth of cut without issue.

I almost always plane 2mm at a time in white oak........Rod

[Bill Berner]

Thanks. That is very useful to know. I cut the nut off the end of the infeed roller last night. The inside of the nut was worn almost smooth, the washer behind it was bent out of shape, and the opening in the spindle was worn very badly on two sides. I forwarded to Felder support, but my suspicion is that the assembly was not seated correctly from the start, and every time I planed something the force transferred from the roller to these other parts which became damaged. That might also explain why I was never able to plane anything thicker than 1.5mm. I'll see what they say.

The machine will plane the specified depth of cut without issue.

I almost always plane 2mm at a time in white oak........Rod

[Bill Berner]

Thanks. That is very useful to know. I cut the nut off the end of the infeed roller last night. The inside of the nut was worn almost smooth, the washer behind it was bent out of shape, and the opening in the spindle was worn very badly on two sides. I forwarded to Felder support, but my suspicion is that the assembly was not seated correctly from the start, and every time I planed something the force transferred from the roller to these other parts which became damaged. That might also explain why I was never able to plane anything thicker than 1.5mm. I'll see what they say.

Wanted to post that Felder is saying it's not a warranty item because I did not report it within 2 months of receiving the unit. They shared no theory for how I might have done something to cause the damage, but said that maybe it had been damaged in shipping.

So now I am waiting for an eight-hour onsite repair with a bill of ~$1600 parts and labor. This after having used the device for maybe 40 hours.

So my advice to anyone buying a Hammer product is to run it hard up to the specified limits when you first get it, and complain like hell if anything does not work as advertised.