# Ski planing using a 1 3/4" bottom cleaning bit



## harrysin (Jan 15, 2007)

Yesterday I received my 1 3/4" bottom cleaning bit from America and had to test it straight away, with rather surprising results. It took very little time to plane the surface of this very cupped piece of Jarrah, I then, having a reference surface, cleaned-up the other side because it fitted into the planer. It could well have been flipped over and planed like the first side. On close examination I could feel small ridges in the routed side which at first puzzled me. After a while it dawned on me what probably caused it, the four corners were not EXACTLY the same height, and with such a large bit it was tilted a fraction. With a smaller straight bit this would not have been at all a problem and to prove the theory I fitted the 25mm (1") bit that I normally use and re-planed the piece and it was now perfectly smooth.
My conclusion is that if one wants to precision set the four corners of the Skis, which takes time, then the large bit would be fine, but if a quick set-up is the order of the day, then a smaller bit would be the way to go and probably be the fastest of the two.


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## jschaben (Jun 21, 2009)

Thanks Harry, I've had the same issue using that bit in my Woodhaven jig. I hadn't taken the time to figure out what the problem was as everything sanded out fine. That was on my RoundTuit list
Thanks again.:thank_you2::thank_you2:


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## Al Robins (Jul 13, 2009)

Thanks Harry.....I was wondering as to the results of your bigger bit. I have the smaller version and it works well after a little practice.The major influence I find is dont try to take off too much ......couple of mill at the most. It may take a little longer, but the end result is far better...................AL


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## jw2170 (Jan 24, 2008)

Thanks Harry,

I will use that trick on the jarrah I plan to use on my face frame.


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## The Bench Dawg (Aug 22, 2011)

Great idea Harry,
What is the diameter of the steel rods holding the router? 
Keith


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## harrysin (Jan 15, 2007)

The Bench Dawg said:


> Great idea Harry,
> What is the diameter of the steel rods holding the router?
> Keith


The diameter of the ski rods does of course depend on the size of the holes in the particular router. In the case of my Makita routers this is 12mm, a fraction smaller than 1/2". Here is a zip file on making skis.


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## Marco (Feb 21, 2009)

Thanks for the Post and pic's Harry...... a 1 3/4" bit is on my list....... growing list for the shop.


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## Al Robins (Jul 13, 2009)

*Maximum Ski Height*

Whilst we are on the subject of Router Skis, whats the maximum height for the cheeks. I have some large blocks that I cant put through the planer or jointer which are over 150 mm or 6 inches in height.

I can lock the workpieces down (somehow) so that is not an issue.and obviously I would have to make new cheeks which is not a problem..... Regards......AL


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## harrysin (Jan 15, 2007)

Al Robins said:


> Whilst we are on the subject of Router Skis, whats the maximum height for the cheeks. I have some large blocks that I cant put through the planer or jointer which are over 150 mm or 6 inches in height.
> 
> I can lock the workpieces down (somehow) so that is not an issue.and obviously I would have to make new cheeks which is not a problem..... Regards......AL


 Basically, if the slots in the end cheeks are 6" in length, then you couldn't use the skis on a project that is 10" in height. In other words the cheeks can be as tall as you wish, so long as you are tall enough to see what is happening at the bit. This is unlike the length of the rods, which if they are too long will cause sag.
For my height and the height of my bench, 13" would be about the limit.


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## Al Robins (Jul 13, 2009)

harrysin said:


> Basically, if the slots in the end cheeks are 6" in length, then you couldn't use the skis on a project that is 10" in height. In other words the cheeks can be as tall as you wish, so long as you are tall enough to see what is happening at the bit. This is unlike the length of the rods, which if they are too long will cause sag.
> For my height and the height of my bench, 13" would be about the limit.


Thanks Harry, that was about what I thought............AL


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## darrink (Sep 7, 2009)

I guess I got lucky with mine. The first time I used that same bit, my board came out smooth with no ridges. As a matter of fact, I didn't even sand the pieces, which I used for drawer fronts on my router table.

http://www.routerforums.com/jigs-fixtures/29019-first-use-my-skis.html


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## bobj3 (Jan 17, 2006)

Hi

Right On, it comes down to what you want to use the ski jig for, the Alum.rails is the best way if you want to use it for planner..

"One of the members promotes threaded rod (or similar)"
I still do ,you don't need to use the light weight threaded rod (1/4" or 3/8" or 1/2") if you use 1" diam. threaded rod it will support any router and the router and will not sag and not cost a ton of money to make a set.

Each time I try and make a new jig like the ski jig I do it so others can do it also... and not break the bank to do it...
That's why I suggested / push the big bit from George (eBay seller) for 14.50 dollars..
1 pc 1/2 Sh 1-3/4" Diameter Bottom Cleaning Router Bit | eBay


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darrink said:


> I guess I got lucky with mine. The first time I used that same bit, my board came out smooth with no ridges. As a matter of fact, I didn't even sand the pieces, which I used for drawer fronts on my router table.
> 
> http://www.routerforums.com/jigs-fixtures/29019-first-use-my-skis.html


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## harrysin (Jan 15, 2007)

I'm sure that I will be using that bit in the future where the router is sitting on a template, ensuring that it is parallel to the work Bob.


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