Disaster in the workshop!

[wizer]

I was really determined not to post about this until I had finished it, but as usual, I have made a ****-up.

I am making a baby walker for daughter's birthday in a couple of weeks. Everything has been going well.

I made the dowel for the handle on the router table, which went very well. Worked first time with no problems. Except, the dowel ended up 24mm. All I had was a 22mm and 25mm forstner bit. 25mm was too big:

So I jumped in the car and drove (an hour) down to Axminster. Picked up a 24mm Forstner bit. Got back, tested it on some scrap. The fit was snug but I thought it would fit fine with gentle persuasion.

Today was final assembly. Everything sanded down and ready to go. Glue in the hole, then dowel, tapping it in, more tapping it in, then:

:evil: :evil: Expletives galore. It cracked both sides.

So I guess the dowel is 24.5mm!

I have planed up some new boards ( left over size for tonight, just incase):

Question is (finally):

Should I try to enlarge the hole somehow OR try to sand the dowel slimmer OR drill the holes as round mortices (not all the way through), giving the hole more strength to tap the dowel in.

Help desperately appreciated.

A Gutted wizer!

 

[matt]

Nice walker. I would try and ease the hole to the larger diameter. Once glued you should have the same strength as a mortice. You could drill the 25mm hole and then cut the end of the dowel and drive some splines in to spread it (just enough to make contact...)

Not wishing to add to your woes (altho I think you're in a good place to remedy this one if it is a problem); however, it looks as though the handle sits behind the centre line of the rear axle. Normally this means that there is more risk of the cart flipping up. It may just be the angle of the shot and, in some cases, the effect is variable in any case - so perhaps, in reality, not a problem.

 

[WellsWood]

Definitely sand the dowel for a nice easy fit. I'd say if it needs "tapping" in it's too tight - especially given the thin wall and short grain of the upright.

Does the dowel have to go all the way through? You could simply make a socket, since you're using a forstner bit, then you wouldn't particularly need to glue it at all.

 

[Mr Ed]

Wizer

My first rule in these situation is think the remedial action through carefully and take your time - don't make a knee jerk reaction (as I have done in the past :roll: ) and make matters worse...

I would get some glue in the cracks and clamp it up - I've had loads of minor cracks like this and they usually go back together fine.

I would reduce the diameter of the dowel at the end rather than mess about with the hole now it is weakened. One way of doing this is on the tablesaw - lower the blade right down so the teeth project by the amount you want taken off and then rotate the dowel over the blade - it will take off an even amount all round effectively making a small round tenon to fit the hole you have. Use the sliding table in a fixed position to keep the dowel square to the blade while rotating.

Cheers, Ed

 

[hpl]

Hey Wizer, I thought from what I had read that you only collected tools and never got round to using them :lol: :lol:


The walker looks very good, and are those corners dovetailed?

I'd put that abranet to good use and sand down the dowel. From the second picture it looks like the dowel has a high spot or two, if so they would sand down easily, or maybe even a light touch with a plane would take the high spots down.
Also it would help if the hole was slightly further down the handle, or the handle longer, so that there was more strength above the hole.

Johnny B

 

[wizer]

it looks as though the handle sits behind the centre line of the rear axle. Normally this means that there is more risk of the cart flipping up.

This is something I deliberated over quite a bit. Looking at the commercial one, the handle is normally at the back of the cart and has a very light angle backwards.

I didn't do well in science, but my reasoning was that my curved rail protruded out the back far enough for her to walk behind it without her feet kicking the cart, but also transferred the downward force through the centre of the back wheel. I share you concerns about it flipping backwards. Maybe the new handles should be mounted further forward and more curved?

Does the dowel have to go all the way through?

No. In fact that was ****-up number one! I drilled one of the 'mortices' on the wrong side! Silly, I clamped up the first one in the drill press, then just assumed the second one would clamp in the same way. Clearly it had to be flipped. So I had to go with through dowels to remedy the situation :roll:

don't make a knee jerk reaction

Too late Ed, one of the handles is now useless through further 'testing'

Hey Wizer, I thought from what I had read that you only collected tools and never got round to using them :lol: :lol:

Mike G instructed me to make something... I had no choice!!

 

[WellsWood]

Does the dowel have to go all the way through?

No. In fact that was ****-up number one! I drilled one of the 'mortices' on the wrong side! Silly, I clamped up the first one in the drill press, then just assumed the second one would clamp in the same way. Clearly it had to be flipped. So I had to go with through dowels to remedy the situation :roll:

DOH! #-o
Still, at least you found another excuse to post a picture of the new TS :wink:

 

[wizer]

Here are some side shots for the flipping issue:

 

[joiner_sim]

As already said. I would sand down the dowel to fit the hole. Also as someone has suggested. The cracks could be glued back up, as long as if the glue is left to fully go off. 24 hours.

Looking good anyway! Good luck completing it without much more hassle :roll:

 

[Digit]

Shame! But we've all probably had the same thing happen at some time.

Roy.

 

[MikeG.]

Mike G instructed me to make something... I had no choice!!

Oh I see, its my fault now!! :wink:

I think Ed is right......reduce the diameter of the ends of the dowel a bit, and glue it all up.....even if a complete piece has broken off the uprights.

As for overbalancing, there are two solutions. Either counterweight the front end of the cart.........seems a bit harsh to ask a toddler to push around a cwt of concrete though......or some sort of low-level skid projecting out of the rear. They might clear the ground ordinarily, by say 10mm or so, but when overbalancing occurs they would prevent a complete tipping. They could just be planted on the underside of the cart, and project back 6 or eight inches, maybe.

By the way, I would be interested to see the jig you used for making dowelling on the router.

Mike

 

[wizer]

Thanks Mike, that's an interesting idea, I will mull it over.

No jig was used. I used a 12mm round over bit. Set the bit height and fence so it rounded exactly one quarter of 24mm square stock. I decided to leave the 2 end square to give me support all the way round. Rout all 4 sides. Sand smooth and cut off the square ends. It works really well.

 

[matt]

With the current handle in place can you not get a feel for susceptibility to flipping? Looking at the pics it does look like the risk exists but it is hard to tell. Depending on the terrain where it is likely to be used, you could add a couple of blocks underneath at the back of the tray (flush with the back) so if it starts to flip the blocks lift the rear wheels and create some drag and stop it rushing away from your littlun. You could even add some rubber pads to the blocks to help apply the "brakes". Similar to the skid idea but without the protrusion.

My daughter's truck was purchased (shame on me...) and the handle was quite far forward. She did end up kicking the tray as she walked but she didn't seem to care :roll: . Unfortunately it's long since packed away otherwise I'd take a photo for you.

 

[Paul Chapman]

Wizer,

Rather than make the handle a tight fit and risk it splitting again, why not make it a nice, sliding fit, then drill through the upright piece, through the round handle and glue in a 6mm or 8mm dowel. That would hold it all together and be plenty strong enough.

Other than the problem with the handle, it looks like a super job 8)

Cheers :wink:

Paul

 

[wizer]

Been looking around at the commercial examples

There doesn't appear to be a standard way of doing it. Some flare out over the back, some don't.

It will be mainly used on thick carpet (hence the chunky wheels) but TBH I'm not certain it will be very pushable. I think the 'brake' idea is certainly worth thinking about.

Thanks

 

[wizer]

glue in a 6mm or 8mm dowel.

I like that idea Paul, thanks.

 

[OPJ]

I've encountered similar challenges recently where I don't have a forstner bit to match the size of hole required. So, I cut most of the hole away with the a bit that's one size smaller and then go to the bobbin sander to ease the fit. It's worked well with the 40mm pipe I've been adding to my router table - which is actually 41mm, by the way!! :roll:

Your design looks good though. I'm sure the split will glue back together just fine - as long as you don't use too much glue... :wink:

 

[Paul Chapman]

I think the 'brake' idea is certainly worth thinking about.

I wouldn't worry about a brake. I made a similar one for my kids 30-odd years ago. From what I remember, when they were very young they wouldn't push it fast enough to worry about stopping. Later they would race me up and down the garden when I was cutting the grass - they usually won

Cheers :wink:

Paul

 

[wizer]

So, I cut most of the hole away with the a bit that's one size smaller and then go to the bobbin sander to ease the fit.

Another good idea, wish i'd thought of that! Well if I ****-up the mortices on the next set of handles, I can use that tip

 

[Shultzy]

Here's a tip about enlarging the hole a fraction. Take a piece of dowel about 6mm less than the dia of the hole. In the dowel saw a slot in the end. Cut a strip of sandpaper, put in slot and wrap around dowel anticlockwise and fit into pillar drill. There's enough pressure from the rotating paper to sand a few thou off at a time. With large dia dowels it may be necessary to drill a hole in the centre to fit another piece of dowel that will fit into your drill chuck.

Although its no help now I would have turned a couple of buttons to fit in the ends, which makes a neat job.