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has anyone had any luck using a drill press and a jig for slotting bridges? it seems an easier task to make a jig to hold and slide the bridge, than to make a jig to carry a small router, I have a dinasour of a delta drill press, the kind you move the belt to a different pulley to change the speed. but the thing is heavy , the table seems very close to perfectly level . it also has a depth stop. I am thinking a mill end in the chuck , and a small set up to slide the bridge at the right angle .just wondering if anyone has any experience with this .. good or bad , thanks Jody

You could do it but drill press bearings aren't meant to take radial (sideways) forces. So if your bearings are a little worn you may have vibration or 'chattering' problems. The other problem I've experienced is that after a certain time, sideways pressure can make the chuck drop off! So it's not something I'd recommend.

IME a drill press does not spin fast enough, so you would have to take a few shallow passes until the desired depth is achieved. As pointed out vibration can be an issue.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

It works for me. I mount the bridge to a carrier board so that intended slot is parallel to the edge of the carrier board and adjust the fence as necessary. I use the fishtail bits from micromark. http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=80247 They have multiple small flutes so there isn't the kickback you might get from a single flute bit when run at a drill press speed. I recently noticed that the borg has dremel bits that look a lot like these for less than $10, fwiw. It takes me ~ 4 passes but it produces a clean slot. I would agree that drill press bearings aren't made for this process, but I would also suspect that the use of a sanding drum is much more harmful to a drill press than this.

I've slotted many bridges with a set-up like BobK on the drill press. I use a similar fluted bit and run my press at its highest speed (8,000RPM). I agree that it's probably not great for the bearings, but I'm sure it's no worse than some of the other things my press gets used for.

Cal

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Remember, there are no stupid questions, only stupid answers!

Hmmm, I have an older Delta bench top drill press... wonder if I can change that bearing...

Mike

It's so much easier to do this job with a router table and fence, and temporarily gluing a wedge shaped piece of wood on the edge of the bridge… One pass is all it takes.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Do you run your saddle slot all the way across the bridge (like on vintage Martins) or, if not, how do you plunge the router bit into the work while holding the bridge blank on the table?

Joe

I'm with Laurent on using the router. However, I use a jig where that holds the bridge blank in place and the router runs over the top. I plunge by hand, but if you have a plunge base for your router you could use that instead. I make two passes to get the final depth. I'm nervous about breaking that small bit.

Steve

I use my drill press all of the time with a cross-slide vise to slot bridges. Here is a thread where we discussed this at length a while back.


viewtopic.php?f=10101&t=17113

Regards,

Peter

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Peter

I did a similar thing to Peter using a machining vice, I'm sure its not the smoothest or best method but it worked out ok.

Is it recommended by most builders or tool makers? no
Will it work for a hobbyist who makes an instrument or two a year? You bet.

I've been using the instructions from the Cumpiano book with great success. It took some practice but my simple jig works for me.
Was there Chattering? Yep. Do I take Multiple passes? Yep again.

Can I do a perfect slot with practice? Absolutely.

Good luck on your bridge.

Dave

I do both, although these days it's mostly drop-in saddles.
If the bridge blank bottom and glued wedge meeting the fence are dead flat and dead perpendicular it's pretty easy. The 1/8" bit sticks out the table .200" max, pressure on the blank is exerted toward the fence and down. For the entry and exit of a drop-in saddle I mark the outside of the bit with a square on a piece of masking tape attached on the fence, fence is on the right side. Once done I continue to firmly hold the blank and turn the router off.
It takes 15 minutes maximum including set up, gluing (thick CA and accelerator) and truing the wedge scrap to the blank, routing and clean up.
No jig, carriage or multiple passes, it's pretty simple and clean. Although the hand is pretty close to the bit so caution is recommended.
I tried the drill-press thing and thought it was more aggravation than I needed, but mine spins only at 3650rpm max.
I think Sobell routs his slots on the drill-press so obviously it can be done neatly.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Not trying to be a smart ah here but I'm really not sure I get the bit about this operation not being a good idea for the bearings of your average run of the mill drill press.

I have not pulled a drill press apart myself as I have not had the need as yet. But unless I have this all wrong, these look an awful lot like standard roller bearings here. The kind which are press fitted onto a shaft, the kind that are just like those roller bearings that press onto the shaft of the rear axle of your truck or car. The only difference I can see, is that if anything, the drill press bearings are probably bigger due to the larger diameter of the shaft.



So I got to wonder, these roller bearings seem to run pretty good for around 100,000+ miles with the weight of a car or truck pushing down laterally onto their shaft. Whats more, they do so over bumpy pot holed roads, up kerbs, over pedestrians and dead kangaroos with out too much maintenance being required.

Could someone please explain what it is that makes the larger more robust roller bearings pressed onto the spindle of a drill press so much more sensitive to the lateral pressure of an operation like that described above or in the use a Wagner Safe-T-Plane than those bearings that sit on the shaft of a fully loaded prime-mover?

Or is it that we are dealing here with yet another urban myth based upon the assumptions of well meaning people? My money is on the later. I for one shall continue to vigorously use my drill press with as much lateral pressure as I can muster just to prove me wrong. When it all finally falls apart, I'll not admit it to anyone, rather I shall fit a couple more $10 bearing to it and take my secret and my pride to the grave

Cheers

Kim

I have a Grizzly radial arm drill press and I use it with an X-Y vice to do light milling work in wood. I don't worry about the bearings because they are pretty hefty (Kim -- Thanks for the photo's!). I'm not a mechanical engineer , but I just can't see these sorts of bearings being destroyed by milling wood. I do think that there are two issues that need to be considered 1) the spindle speed and 2) runout of the chuck. The Grizz tops out at 3750 rpm, 1/6 the speed of a router -- probably the biggest issue in my mind regarding chatter. The drill press is also a tool that needs to be tuned after coming out of the box. Here is a link to a .pdf that was originally an article in FWW. http://www.rvplane.com/pdf/drill_press_tune-up.pdf regarding tuning a drill press.

If a person has a jig or an X-Y vice that allows repeatability and they are willing to take lighter cuts, I'm thinking that the drill press will work OK.

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Jim Howell
Charlotte, NC

My drill press (Delta-Milwaukee), now nearly 70 years old, has an XY vice, and was used extensively for milling metals for years. It was my fathers, and that's probably about 40% of the use it got. I can remember watching him mill key slots in shafts, when he was designing and building machinery in our basement. (It was his hobby, but he built machines for use in his business.) I think, I'm finally going to have to replace the top bearing, as it has begun to make a light knocking sound. Somehow, I don't think it's because it was used for milling. If that had been the issue, the lower bearing would have gone years ago.

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Waddy

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Sound Clips of most of my guitars

I agree Waddy,

Chances are that CONSTANT lateral pressure over the last 70 years from belt tension at the top of the spindle on the drive pulley has finally done in the top bearing. Whilst I would be incline to replace the bearings as a pair, I reckon you could actually get through years more work before the bottom bearing ever succumb to the periodic lateral pressure experienced from milling operations.

Cheers

Kim

I tried using a jig and router and had trouble getting the bit to plunge in exactly where I wanted it to go. Now I use my Delta bench top drill press to mill saddle slots. I got a sliding vice from Grizzly to hold the bridge and slide it under the bit. The bit speed doesn't really seem to be an issue, I get nice clean slots with this method. The trick seems to be to making multiple shallow cuts, and the sliding vise makes them easy to control.

Since I make only a few bridges a year, I'm not too worried about the bearings wearing out too soon. Someone mentioned being more concerned about the effect of using something like the Luthier's Friend sander, and I would have to agree with that.

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53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/

I use my Craftsman drill press for all my slots... It's the only operation I do that requires 2 people.
So...my wife gets to help! See lowers the bit slowly as I slide the carriage back and forth between the stops... so I'm doing like twenty passes... it cuts real easy and only takes about 30 seconds.

long

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"No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus of Ephesus

Hi Jody,

The drill press method should work for you, as attested to by others here.

I use a PC 310 router in the Bishop Cochran plunge base, with a jig I built. I don't have pictures handy to post, but I could try to do that if you want.

I've done it the way Laurent describes (more or less), but I built this jig for the PC-310 with the plunge base when I decided to put a back tilt on my saddle slots. I don't remember if you got a close look at my alto guitar at the GAL convention. If so, you may have noticed how the saddle leans back. The geometry of that could be done with a jig on a drill press as well, but I went with the router.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Cheap Craftsman drill press, cross slide vice, single fluted router bit and a simple jig to get the right angle....Takes all of five minutes to make the slot and I love every minute of doing it..If I didn't, I would buy the darn bridge.....Everybody does it in the way they are comfortable with... ....Larry

I'm glad "do it the way you're comfortable with" was stated - I was about to rethink my bridge slotting process, which is done on a router table, with a stopped jig to limit the slot width.

By having the jig with a slot width of 1/8" (same as the saddle slot), I can use an upcut bit and not worry about tearout (not that it happens much anyway). With a plunging spiral bit, and two (to 3) passes, I'm glad I threw the router under the table.