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Dissappointed with Leigh Super FMT jig

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Forum topic by Joel_B posted 11-08-2015 06:15 PM 910 views 0 times favorited 12 replies Add to Favorites Watch
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Joel_B

294 posts in 841 days


11-08-2015 06:15 PM

I bought a Leigh Super FMT about a year ago and just getting around to using it.
I bought it used but it was almost like new barely used.
So far I ran into the following problems:

Routing a tenon makes tons of dust and vacuum port doesn’t help much.

Very difficult to get the tenon shoulder at a precise dimension as it depends on the plunge router depth setting which cannot be set precisely. I am going to just do mortices and use loose tenons, at least I can get a precise cut on the TS. If I was going to do tenons on the jig I would probably cut the shoulders first on the TS and remove some material with a chisel first to keep down the routing and dust.

I cant get the clamp plate 90 degrees to the table because it is stopped by the vacuum box before it gets to 90 degrees. The first joint did not come out square. I am going to remove the vacuum box for now so I can it adjusted square.

Now I am wanting to get some good mortice chisels and do it all by hand.

-- Joel, Encinitas, CA


12 replies so far

View HarveyM's profile

HarveyM

92 posts in 1482 days


#1 posted 11-08-2015 06:47 PM

It’s small consolation, but you’re not the only one; I bought my Super FMT last weekend from a retired gentleman who found it needed too much fiddling to adjust. He had a Leigh dovetail jig which he seemed to like, but the FMT tried his patience. I’ll be looking for tips this thread will (hopefully) generate.

-- Just a Duffer

View Fred Hargis's profile

Fred Hargis

3926 posts in 1953 days


#2 posted 11-08-2015 06:50 PM

That would be disappointing. I have the aluminum one, and I love it. A couple of things: the tenon depth thing seems to be a router problem, as opposed to the jig. I haven’t had that particular problem using 2 different routers ( a Milwaukee 5616, and a Triton). For the remaining problem (the clamp plate), give Leigh a call…they have astounding customer service and can probably give you some good tips. Haven’t got much to say about the dust,it comes with routing, though I do find on mine the vac catches most of the dust (when cutting tenons) on the backside but not the front. I’m a little opposite of what Harvey described, I find the D$ takes a lot of effort (still does a good job), but the FMT seems to be easy to set up and go.

-- Our village hasn't lost it's idiot, he was elected to congress.

View AlaskaGuy's profile

AlaskaGuy

2406 posts in 1769 days


#3 posted 11-08-2015 07:00 PM

Hey Fred, PM sent.

-- Alaskan's for Global warming!

View Joel_B's profile

Joel_B

294 posts in 841 days


#4 posted 11-08-2015 07:37 PM


That would be disappointing. I have the aluminum one, and I love it. A couple of things: the tenon depth thing seems to be a router problem, as opposed to the jig. I haven t had that particular problem using 2 different routers ( a Milwaukee 5616, and a Triton). For the remaining problem (the clamp plate), give Leigh a call…they have astounding customer service and can probably give you some good tips. Haven t got much to say about the dust,it comes with routing, though I do find on mine the vac catches most of the dust (when cutting tenons) on the backside but not the front. I m a little opposite of what Harvey described, I find the D$ takes a lot of effort (still does a good job), but the FMT seems to be easy to set up and go.

- Fred Hargis

Fred,

I am using a Milwaukee 5616 but can’t seem to figure how to set the plunge depth.
This is from the users manual:

Plunge base:
1. Unplug the tool.
2. Install the bit.
3. Press the plunge release lever and push down on
the handles until the bit touches the workpiece.
4. Loosen the depth stop rod locking screw.
5. Turn the turret so the full depth position is directly
below the rod
6. Press the depth stop rod release button to lower
the rod. It should rest on the full depth position
of the turret.
7. Place the adjustable pointer on “0”.
8. Press in the depth stop rod release button Move
the rod up to the desired depth of cut.
9. Use the depth adjustment knob to finely tune the
depth of cut.
10.Tighten the depth stop rod locking screw.
11.To obtain the cut making multiple passes, rotate
the turret to a higher step. Each step is 1/8”
NOTE: A fine finish can be made using the turret
and multiple passes.

I am baffled by step 9. as the depth adjustment knob has no effect on tuning the depth. My plunge base has no threads in it that mate to the threads on the rod which the depth adjust knob turns, unlike the fixed base which does have mating threads. It just has a large hole that the rod goes into. I can only adjust the depth using the depth stop rod which is in increments of 1/8 inch. Maybe you can enlighten me and how to do the fine adjust. After removing the vacuum port I was able to adjust the clamp plate square to the table. I sent an email to Leigh support, hoping to hear from them tomorrow.

Thanks

-- Joel, Encinitas, CA

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Joel_B

294 posts in 841 days


#5 posted 11-09-2015 02:24 AM

I played some with loose tenons, ran some stock through the planar.
Now I have square tenons with round mortices, what to do.
Make the tenons round or the mortices square? Broke out some chisels and started cutting the mortices square.
Hard to get the right fit, then I decided I should go back to the Super FMT to make the tenons.
So I cut the shoulders on the TS, removed most of the waste with a chisel and then the remainder on the FMT.
The routing went much quicker and there was much less dust. I think this the best approach for me for accuracy and least amount of routing. But now the joint is fitting too loose so I have to play with the adjustments on the Super FMT even I thought I had it right a few months ago.

-- Joel, Encinitas, CA

View AlaskaGuy's profile

AlaskaGuy

2406 posts in 1769 days


#6 posted 11-09-2015 08:18 AM

Round the edges of your lose tenon stock on the router table before you cut to length.

Kind of like this.

https://www.youtube.com/watch?v=J7ceJBdyag0

-- Alaskan's for Global warming!

View Fred Hargis's profile

Fred Hargis

3926 posts in 1953 days


#7 posted 11-09-2015 12:22 PM

Joel, that stop does adjust depth of cut with the knob. There’s a hundred ways to do this, here’s mine: first i cut a gauge block out of scrap hardwood. That is simply a piece of stock to match my stiles in thickness with the shoulder of the tenon marked on it. I kept mine since my tenons are usually always this length. The I cut one shoulder on the TS and remove the waste, cut it about 1/4” deep regardless of what your actual tenon shoulders will be. Use this gauge block by clamping it in the FMT just as you would one of the stiles. Sit the router on the jig and lower the bit to the cut shoulder. Lower the stop rod and lock it. That will usually set your depth, but you may have to fine tune slightly. Raise the router, then plunge again and compare it to the mark for the tenon length….it may need to go up or down (hundredths of an inch). Raise the router, loosen the screw, and watch the scale for this adjustment : if you need the cut to be slightly deeper…raise the pointer slightly (“down” direction on the dial), if you need it to be more shallow do the opposite. Then lock the screw again. Check it again against your mark. Repeat if needed. Cut all the tenons first, because you will have to cut the mortises slightly deeper, which means you have to adjust the stop rod “up just a little”. It sounds like you found a method that you like, so none of this may be of use.

-- Our village hasn't lost it's idiot, he was elected to congress.

View Fred Hargis's profile

Fred Hargis

3926 posts in 1953 days


#8 posted 11-09-2015 03:58 PM

As usually happens my fingers outran my brain in the above post and that aggravatingly short “edit post” time limit has closed it for correction.. So, when I said “stiles” above, I meant rails….but you probably get the idea.

-- Our village hasn't lost it's idiot, he was elected to congress.

View CharleyL's profile

CharleyL

196 posts in 2824 days


#9 posted 11-09-2015 05:50 PM

Joel_B,

I’ve had an FMT (the original aluminum one) for about 10 years, and while I haven’t used it much lately, I really like the jig. It was bought to make over 1650 mortises and tenons on a project, and it paid for itself about 3 times over on that one project. I initially had problems with the dust port clogging, but then just started cutting my long tenons in two passes at progressively longer depth settings. The shorter chips (less than 1”) don’t clog the vac port, where the chips longer than about 1” do. You are right, the vac port doesn’t work very well when cutting the front side of the tenons. I attached a piece of 3/16 clear Lexan to the front edge of my FMT using strips of Velcro so it hangs down between me and the tenon cutting process. The Lexan helps keep the chips from hitting me and it seems to improve the quality of the vacuum pick-up of chips from the front side, but only slightly. I did this mostly to keep the chips from getting all over me. If you make one, be sure to use Lexan and not Plexiglass. Lexan is what they make bullet proof windows from and it won’t shatter like Plexiglass will.

The depth, or length, of the tenon is entirely controlled by the router depth adjustment, so you need one that sets easily and accurately. I always use a DeWalt 618 with my FMT and haven’t had these problems. The mortise should always be 1/8 – 1/4” deeper than the tenon anyway, so there is a place for the excess glue.
If you are going to make floating tenons, don’t worry about the fact that they are square and the mortise has rounded ends. Make the tenon fit the flats of the mortise and leave the 1/2 round areas empty. Glue will squeeze out and fill them. The most strength of the joint comes from the wide surfaces of the mortise and tenon in close contact with each other anyway.

You shouldn’t need to adjust the angle plate on the front of the FMT all the way to 90 deg (horizontal), or am I misunderstanding your statement. 45 deg should be more than enough for this adjustment. On chairs it usually is set to less than 10 deg. At 90 deg there would be no place for your work material between this plate and the top plate of the FMT. As you move this plate out to cut angled mortises or tenons it does restrict the vacuum ability and I don’t think there is a better way, so I believe it’s a limitation that we have to live with. The only alternative that I can see would be to have a second vacuum port across the front, and it would need to be easily removable and adjustable for the size of your stock. You would need two vacuums or a much bigger vacuum system to do this too.

You need to square the stop on the front plate before starting to be sure and get mortises and tenons cut square. If the stop isn’t square there is no way to position your work square to the jig DAMHIKT, or am I misunderstanding this part of your statement too.

If I misunderstood you, please clarify.

Charley

View Joel_B's profile

Joel_B

294 posts in 841 days


#10 posted 11-09-2015 05:52 PM

Fred,

Thanks for the explanation, I think I get it now.
The thing that was confusing me is the depth stop rod has teeth on it that are spaced at 1/8” increments so I thought that was the only adjustment i could make, but by holding in the release button the rod can be adjusted where ever you want it. I also think step 9 in the manual is confusing and/or incorrect. I think this might address my concern with depth accuracy but I still think routing the entire tenon creates too much noise and dust.

-- Joel, Encinitas, CA

View Joel_B's profile

Joel_B

294 posts in 841 days


#11 posted 11-09-2015 05:58 PM



Joel_B,

I ve had an FMT (the original aluminum one) for about 10 years, and while I haven t used it much lately, I really like the jig. It was bought to make over 1650 mortises and tenons on a project, and it paid for itself about 3 times over on that one project. I initially had problems with the dust port clogging, but then just started cutting my long tenons in two passes at progressively longer depth settings. The shorter chips (less than 1”) don t clog the vac port, where the chips longer than about 1” do. You are right, the vac port doesn t work very well when cutting the front side of the tenons. I attached a piece of 3/16 clear Lexan to the front edge of my FMT using strips of Velcro so it hangs down between me and the tenon cutting process. The Lexan helps keep the chips from hitting me and it seems to improve the quality of the vacuum pick-up of chips from the front side, but only slightly. I did this mostly to keep the chips from getting all over me. If you make one, be sure to use Lexan and not Plexiglass. Lexan is what they make bullet proof windows from and it won t shatter like Plexiglass will.

The depth, or length, of the tenon is entirely controlled by the router depth adjustment, so you need one that sets easily and accurately. I always use a DeWalt 618 with my FMT and haven t had these problems. The mortise should always be 1/8 – 1/4” deeper than the tenon anyway, so there is a place for the excess glue.
If you are going to make floating tenons, don t worry about the fact that they are square and the mortise has rounded ends. Make the tenon fit the flats of the mortise and leave the 1/2 round areas empty. Glue will squeeze out and fill them. The most strength of the joint comes from the wide surfaces of the mortise and tenon in close contact with each other anyway.

You shouldn t need to adjust the angle plate on the front of the FMT all the way to 90 deg (horizontal), or am I misunderstanding your statement. 45 deg should be more than enough for this adjustment. On chairs it usually is set to less than 10 deg. At 90 deg there would be no place for your work material between this plate and the top plate of the FMT. As you move this plate out to cut angled mortises or tenons it does restrict the vacuum ability and I don t think there is a better way, so I believe it s a limitation that we have to live with. The only alternative that I can see would be to have a second vacuum port across the front, and it would need to be easily removable and adjustable for the size of your stock. You would need two vacuums or a much bigger vacuum system to do this too.

You need to square the stop on the front plate before starting to be sure and get mortises and tenons cut square. If the stop isn t square there is no way to position your work square to the jig DAMHIKT, or am I misunderstanding this part of your statement too.

If I misunderstood you, please clarify.

Charley

- CharleyL

Charley,

Thanks for the tips. By 90 degrees I mean vertical or square to the top table.
After removing the vacuum port I was able to get it square.
I got an email from Leigh this morning saying they have not heard of this problem and asked for pictures.

-- Joel, Encinitas, CA

View Joel_B's profile

Joel_B

294 posts in 841 days


#12 posted 11-30-2015 12:33 AM

I wanted to post an update after using the FMT some more.
I have spent a lot time trying to get it to make some decent joints.
One problem I found is that the removable sight was not centered wrt the mortice / tenon guide template.
There are instructions for doing this in the manual and after a I adjusted my joints are lining up better.
Also had to play more with another adjustment to get the right fit between the mortice and tenon.
A few things I really dislike:

Every time I put a new piece of wood on it I have to lift the heavy router and attached plate off of it, put the sight on, line up and clamp the wood, remove the sight, put the heavy router back on top.

The right angle guide on the clamp plate is a joke. It is very hard to keep to square while sliding it back and forth while lining up the work piece to the sight. Making small adjustments is difficult and frustrating.

Moving the two clamps is difficult as it requires reaching around the back to pull them out the holes in clamp plate and relocate to them to different holes.

I am thinking a way to improve things would be to mount a series a T-Tracks to the clamp plate so I could do all of the clamp adjusting from the front by just sliding the clamps around. I could also use on these micro adjusters in place of the right angle guide:

http://www.woodpeck.com/microadjust.html

-- Joel, Encinitas, CA

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