Slot mortiser / poor man’s Festool domino

[jb94]

Thought I’d share my finished machine, to give others ideas and to receive feedback / improvements etc.

I’m making a lot of bars for a crib and needed a good way to attach them strongly to the stringers but don’t want to spend hours and hours manually drilling dowels or cutting M&T:

Video 1
Video 2

Just made from scrap materials around my workshop.


In an ideal world I’d have a better raise / lower mechanism, it’s a sliding joint stopped by a bolt at the back, but it does the job.

 

[alan895]

Looks very nice. Quick question: does using full extension drawers slides generate much play which could impact the accuracy?

 

[jb94]

Looks very nice. Quick question: does using full extension drawers slides generate much play which could impact the accuracy?

there was a bit of play in the topmost sliders (left-right action) causing the bit to have up-down play.

I added some wooden blocks with machine screws over the sliders to act as a tensioner which minimised it.

I also found that adding a handle as low as possible reduced play, as originally I was holding right at the top which acted as a lever.

 

[pe2dave]

I'm impressed.

 

[ade99]

Yup, me too!

 

[John Brown]

Me too. I have quite a collection of drawer slides sitting around doing nothing. Just need to source a cheap palm router...

 

[BucksDad]

Nice. Was expecting some complicated contraption but that looks cheap and quick

 

[Molynoox]

That's very cool, well done

 

[benitod]

Hi, jb94. Welcome to the forum
Nice and simple contraption. Your accuracy could be improved by using some linear bearings bars to reduce the play.

 

[Spectric]

Very good idea using drawer slides, the best are Accuride but as @benitod has said use linear bearings like these for even less play.

https://uk.vevor.com/linear-guide-r...-hsr15-1200mm-linear-slide-kit-p_010281269153

 

[Blister]

Looks like you are getting jiggy with it

 

[jb94]

Hi, jb94. Welcome to the forum
Nice and simple contraption. Your accuracy could be improved by using some linear bearings bars to reduce the play.

Absolutely for a mk2 I’d go for higher quality components, but hopefully this setup will do what I need it for and the only cost was the ¼ inch bit.

 

[johnnyb]

I always liked slot morticers tbh. Accurate and simple to use. My axi planer was a prototype having features not present on production machines. Bolts for a slot mirticer was one. Table extension tapped holes another. Are those fancy drills still available as clico are defunct.

 

[Deadeye]

Matthias Wandel has a nice, rigid build of one of these.
I cheated and used a second hand mortising table off an Inca saw. The hardest thing was getting a router mounted precisely. I felt a palm router was underpowered for the cuts needed and all the beefier ones were in odd shaped housings (I needed to remove the base for depth of cut)

 

[jb94]

Yeah it’s Mathias who I have stole the idea from! His is an excellent bit of kit with a screw adjusted height, something I’d like to replicate for MK2.

The makita router seemed fine cutting into hardwood with 40mm tenons (20-25mm cut depth), maybe if I used beefier tenons and had a bigger cut depth it may struggle more but I think it’s fine for what I need it for.