LumberJocks

Mortiser problems

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by Tennwood posted 08-11-2017 01:21 PM 500 views 0 times favorited 11 replies Add to Favorites Watch
View Tennwood's profile

Tennwood

111 posts in 2959 days


08-11-2017 01:21 PM

Topic tags/keywords: mortiser

First I must say that I have never owned or used a mortiser before so this is all new to me.
I purchased a Rikon mortiser recently and have begun to try it out. I got the mortiser because I want to make through mortises with clean sharp edges. Until now I have used a router (and occasionally an drill press and chisel) for my mortises. It came with 4 bits/chisels. I cleaned up and sharpened the bits/chisels and set up the machine per a Fine Woodworking article by Roland Johnson. One problem (among others issues I have with the machine) is that I am getting rounded edges on the cuts. It is like the bit is rounding out the hole before the chisel makes its cut. I adjusted the chisel/bit clearance at several different settings and get the same result.
I don’t know if this is an issue with the set up, the machine or with the chisel/bits that came with it.
This isn’t the only problem I am having with the machine but is the most glaring at the moment. Once I get more familiar with it, I will do a review. Right now it would struggle getting two and a half stars.
I would appreciate any ideas or lessons here.

Thanks as always.
Jim

-- Jim, SE Tennessee, "Don't spare the kindling Dear, we have plenty"


11 replies so far

View builtinbkyn's profile

builtinbkyn

1827 posts in 718 days


#1 posted 08-11-2017 01:27 PM

Hi Jim. I had similar issues with a used Shop Fox mortiser I picked up. Check you’r bits again. Particularly the inside bore of the chisel. The bits I had were very poorly machined on the inside, preventing the chips from ejecting properly. I had to clean them up with a file and sandpaper. Then I applied some wax and this helped tremendously. Also, as you already know, setting the drill inside the chisel so that there’s some clearance is important. There are all sorts of recommendations on the net for how to go about doing it. My mortiser is now ballast for my bench as I don’t really use it because it seemed more trouble than it was worth. I’m sure a really god full size machine would do a much better job than my benchtop model.

-- Bill, Yo!......in Brooklyn :)

View AandCstyle's profile

AandCstyle

2855 posts in 2035 days


#2 posted 08-11-2017 08:58 PM

Jim, I can’t imagine how you can get rounded edges unless the chisel is entering the stock at an angle. Maybe a picture or two would help. Sorry I don’t have an answer for you.

-- Art

View builtinbkyn's profile

builtinbkyn

1827 posts in 718 days


#3 posted 08-11-2017 09:15 PM



Jim, I can t imagine how you can get rounded edges unless the chisel is entering the stock at an angle. Maybe a picture or two would help. Sorry I don t have an answer for you.

- AandCstyle


Art, it sounds like the bit is crushing the fibers at the entry of the cut. So he’s not getting a crisp line on the face. I had the same issue. The bits “seemed” sharp, but the hollow inside the chisel was very rough, preventing the evacuation of chips and the cutting edge wasn’t really sharp because of the poor milling on the inside edge of the chisel. That is crushing the fibers before they’re cut, leaving a rounded over edge or line. Well I’m guessing that’s what he was referring to :)

-- Bill, Yo!......in Brooklyn :)

View AandCstyle's profile

AandCstyle

2855 posts in 2035 days


#4 posted 08-12-2017 10:27 PM

Bill, if your diagnosis is correct, maybe these cone sharpeners would help.

-- Art

View builtinbkyn's profile

builtinbkyn

1827 posts in 718 days


#5 posted 08-12-2017 11:30 PM



Bill, if your diagnosis is correct, maybe these cone sharpeners would help.

- AandCstyle


Well the OP hasn’t gotten back to us so we really don’t know lol I thought about purchasing those cone sharpeners back when I was dealing with this, but careful filing/sanding helped. I think I also used the cone shaped Dremel attachment, if I remember correctly. I made a thread on my issue with the mortising chisels. I haven’t touched the mortiser since completing the bench.

-- Bill, Yo!......in Brooklyn :)

View pintodeluxe's profile

pintodeluxe

5370 posts in 2591 days


#6 posted 08-13-2017 05:36 PM

A couple things contribute to the problem you’re having. Runout of the machine can be a culprit. Sometimes the drill bit is not perfectly straight which makes the tip of the bit travel in a larger circle than normal (bit squealing is a telltale sign).

I have a Delta bench top unit, as well as a Jet floor model. The Jet makes much cleaner holes with the same chisels. The mid priced chisels like the Jet brand are pretty good. I have been able to get good results with the bargain chisels too, but you need to grind down the diameter of the drill bit. Chuck just the drill bit into the machine, and hold a sharpening stone against the bit. Go slowly and test the bit often.

Which model Rikon did you get? The one with an X-Y table typically gets very poor reviews. I was planning on buying that model because I really wanted an X-Y table. The same tool has been sold under different brand names, and FWW magazine once said it was the only mortiser tested that wouldn’t make acceptable mortises. I then compared it to a floor mortiser, and realized the Rikon has quite a few shortcomings. However I made thousands of really clean mortises with my bench top unit, so maybe there’s hope. The best woodworkers have a way of getting excellent results with average tools.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Tennwood's profile

Tennwood

111 posts in 2959 days


#7 posted 08-18-2017 11:55 AM

Art an Bill – I got one of the cone sharpeners from Woodcraft when I got the machine. Maybe I need to do some more work on it. If that doesn’t work I will try pintodelux’s idea of taking the bit down some. The description you gave seems accurate on what is happening. I hope it isn’t a run out issue.

Pinto – I did get the XY machine. I liked the idea of quick adjustment. I am still playing with the machine but the two other problems I am having are: the hold down – it uses diagonal pressure from the front instead of the conventional hold down from the top which doesn’t hold the wood down if it gets hung up. The depth stop – the depth stop is a threaded bolt tighten to a hex rod with a set screw. The stop on the head missis the bolt and it the bolt cannot be adjusted over because the set screw won’t catch on the side of the hex rod then. I put a washer on it which works but then I noticed the bolt flexes when the stop hit it.

Again, I am brand now to mortisers but another thing I noticed about the bits is you can hear them clinking (kind of a light tinking sound) in the chisel when the machine is on. I didn’t know if this is normal or something is not straight. It does it with all the bits.

If I cannot get these bits to work I may purchase some premium bits from Lee Valley and give it a go.

Thank you for everyone’s input.

-- Jim, SE Tennessee, "Don't spare the kindling Dear, we have plenty"

View firefighterontheside's profile

firefighterontheside

16432 posts in 1634 days


#8 posted 08-18-2017 12:51 PM

These are long narrow bits, they are gonna flex and touch the inside of the chisel. There’s nothing you can do to stop that. Getting the bit set at just the right depth thru the chisel is a bit of a trick. If the head of the drill bit is too far in, you will get binding and the chips will not clear. Too far out and the bit is allowed to flex too much. The end of the chisel is what keeps the bit centered.

-- Bill M. "People change, walnut doesn't" by Gene.

View bonesbr549's profile

bonesbr549

1435 posts in 2845 days


#9 posted 08-18-2017 01:22 PM

As others said a good cone sharpener, and don’t under estimate the quality of the bits. Some are better than others.

-- Sooner or later Liberals run out of other people's money.

View pintodeluxe's profile

pintodeluxe

5370 posts in 2591 days


#10 posted 08-18-2017 02:51 PM

The exact depth of a mortise is rarely critical. I trust you can rig something up to make the depth stop work for you.

As far as the clamp not working well… try self adhesive sandpaper like this…
http://lumberjocks.com/pintodeluxe/blog/46209

Good luck with it.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View RobS888's profile

RobS888

2283 posts in 1623 days


#11 posted 08-18-2017 03:10 PM

I have the baleigh version of that mortiser, and I found that scribing lines before using it helps. Mine has a clamp that compresses from the front and I don’t think I have ever had a piece pull up… well if I remembered to tighten it… I do use pieces of white oak to move the piece I’m cutting into the center of the table…1 in the front and 1 in the back. They may help to lock in the piece, not sure.

EDIT:

I eject chips to the right and cut to the left, so the chips go into any previous cut portion. I have a DC hose to pull them out. That may make it easier to pull the chisel out.

-- I always suspected many gun nuts were afraid of something, just never thought popcorn was on the list.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com