[kywoodchopper]

I am using a plunge router to cut crosses in boards. I have been using a 1/2" spiral carbide bit, but the finish cut leave rough and occasional burnt spots - especially in maple. I've been cutting these crosses in box lids for soup kitchens, churches and assisted living places. I have "Prayer Request" engrave along the cross.

I use a guide bushing that is .625" outside diameter. If I used that for the original cuts then swap out that bushing with one that is say .615" I believe the router bit would just be taking off a tiny bit of wood and clean up the cut.

Years ago I was using a 1/4" router bit and purchased two brass guide bushings. One is .434" and the other is .442". By using the .442" bushing first then by swapping to the .434" with the same router bit it would shave off just a tiny bit of wood. I have no idea where I purchase those guide bushing.

I went to a machine shop today and show them what I was trying to do, but was told they couldn't shave any off the current bushing because there wasn't enough metal there.

I tried using a 1/4" spiral bit with the two bushing that I have (.434" and .442"), but the bit isn't long enough. It is 2 1/2" long, and would require around 2 3/4" to 3" long bit.

Does anyone know where I could purchase guide bushing around 5/8" and another either slightly larger or smaller or a 1/4" spiral bit that is around 3" long?

Here is a photo that I posted earlier showing what I am trying to accomplish.

Thanks folks, Malcolm / Kentucky USA

 

[pal]

Try whitside Up Cut Spiral they may have one that would suit you

 

[kywoodchopper]

Try whitside Up Cut Spiral they may have one that would suit you

Nope! I just tried a different router - switched to a Triton router instead of the Freud that I had been using. I think I can use my current 1/4" spiral bit that is 2 1/2". I see that it is long enough. Tomorrow I'll see how the two bushing that I have work as far as cleaning up the rough cuts.

 

[harrysin]

There are two ways in which to increase depth of cut, one is to change to a MUSCLECHUCK which in addition to giving far greater grip on the bit and only requiting a 1/4 turn of a hex key to lock/unlock gives about an extra 1/2" of depth of cut. the second method is to use a 40mm or 3/4" template guide and make new templates. This will allow the any chuck to pass through.

 

[TenGees]

Just a thought, Malcolm. Could you shorten the face that you want to clean by adding a chamfer or round-over to the inside?

 

[kywoodchopper]

Just a thought, Malcolm. Could you shorten the face that you want to clean by adding a chamfer or round-over to the inside?

Had not thought of that. I'll keep that option open. Thanks!

 

[aganser]

We use a down-spiral bit and it gives a better edge.

 

[kywoodchopper]

We use a down-spiral bit and it gives a better edge.

That is what I have been using, but on maple I get burns. If I get a chance today I'm going to experiment some on this.
Thanks!

 

[Souza1969]

I am using a plunge router to cut crosses in boards. I have been using a 1/2" spiral carbide bit, but the finish cut leave rough and occasional burnt spots - especially in maple. I've been cutting these crosses in box lids for soup kitchens, churches and assisted living places. I have "Prayer Request" engrave along the cross.

I use a guide bushing that is .625" outside diameter. If I used that for the original cuts then swap out that bushing with one that is say .615" I believe the router bit would just be taking off a tiny bit of wood and clean up the cut.

Years ago I was using a 1/4" router bit and purchased two brass guide bushings. One is .434" and the other is .442". By using the .442" bushing first then by swapping to the .434" with the same router bit it would shave off just a tiny bit of wood. I have no idea where I purchase those guide bushing.

I went to a machine shop today and show them what I was trying to do, but was told they couldn't shave any off the current bushing because there wasn't enough metal there.

I tried using a 1/4" spiral bit with the two bushing that I have (.434" and .442"), but the bit isn't long enough. It is 2 1/2" long, and would require around 2 3/4" to 3" long bit.

Does anyone know where I could purchase guide bushing around 5/8" and another either slightly larger or smaller or a 1/4" spiral bit that is around 3" long?

Here is a photo that I posted earlier showing what I am trying to accomplish.

Thanks folks, Malcolm / Kentucky USA

Malcolm prior to my career in woodworking, I was a mechanical engineer. If the bushings your referring to are brass, the machine shop is correct. Brass tends to be very soft and what we refer to as 'gummy' machine. Hard to get anything soft to machine well, then add the already thin wall of the bushing and your done! But that isn't the case with mild steel or tool steel. Either is much harder of a metal. So it's more flexible to machine, and by that I mean you've got more options to process the harder metal. In fact with tool steel that's hardened or heat treated you can grind, holding extremely tight tolerances. I think we'd be hard pressed to find tool steel, hardened router bushing off the shelf. But I know for a fact they're available in mild steel, I've seen them a bunch of times. That said I'd bet you could get that machine shop to help you get the outside diameters your looking for. And talk to one of the machinist before making the investment on steel bushings, make sure they'll do it....and if they say no, call another shop. The first guys just don't want to deal with such a small job. You could also check with your local vocational school. Lot of times the shop instructors welcome stuff like this. Give the kids a chance to think out of the box. And Lord knows kids could use some of that these days!

Good luck!


Sharp looking boxes your making, by the way!

 

[kywoodchopper]

Malcolm prior to my career in woodworking, I was a mechanical engineer. If the bushings your referring to are brass, the machine shop is correct. Brass tends to be very soft and what we refer to as 'gummy' machine. Hard to get anything soft to machine well, then add the already thin wall of the bushing and your done! But that isn't the case with mild steel or tool steel. Either is much harder of a metal. So it's more flexible to machine, and by that I mean you've got more options to process the harder metal. In fact with tool steel that's hardened or heat treated you can grind, holding extremely tight tolerances. I think we'd be hard pressed to find tool steel, hardened router bushing off the shelf. But I know for a fact they're available in mild steel, I've seen them a bunch of times. That said I'd bet you could get that machine shop to help you get the outside diameters your looking for. And talk to one of the machinist before making the investment on steel bushings, make sure they'll do it....and if they say no, call another shop. The first guys just don't want to deal with such a small job. You could also check with your local vocational school. Lot of times the shop instructors welcome stuff like this. Give the kids a chance to think out of the box. And Lord knows kids could use some of that these days!

Good luck!


Sharp looking boxes your making, by the way!

Just thinking...there is a fellow in our woodworking club whose father has a machine shop....at least he used to. Not sure about now. I think I check and see if he can do one for me. He made a custom router bit for me years ago. Thanks for the info. I currently have 9-boxes and 3-baskets that I will finish by the first of the week and all will be gone by next week. One 5-year old girl's mom said the girl has a brain tumor. She said the girl is raising funds to help other kids with cancer. I will donate a basket to this girl and see if she has other friends with cancer that I could donate to.

 

[Souza1969]

Malcolm prior to my career in woodworking, I was a mechanical engineer. If the bushings your referring to are brass, the machine shop is correct. Brass tends to be very soft and what we refer to as 'gummy' machine. Hard to get anything soft to machine well, then add the already thin wall of the bushing and your done! But that isn't the case with mild steel or tool steel. Either is much harder of a metal. So it's more flexible to machine, and by that I mean you've got more options to process the harder metal. In fact with tool steel that's hardened or heat treated you can grind, holding extremely tight tolerances. I think we'd be hard pressed to find tool steel, hardened router bushing off the shelf. But I know for a fact they're available in mild steel, I've seen them a bunch of times. That said I'd bet you could get that machine shop to help you get the outside diameters your looking for. And talk to one of the machinist before making the investment on steel bushings, make sure they'll do it....and if they say no, call another shop. The first guys just don't want to deal with such a small job. You could also check with your local vocational school. Lot of times the shop instructors welcome stuff like this. Give the kids a chance to think out of the box. And Lord knows kids could use some of that these days!

Good luck!


Sharp looking boxes your making, by the way!

Sorry just realized your name isn't Malcolm, that's where your from!

Just thinking...there is a fellow in our woodworking club whose father has a machine shop....at least he used to. Not sure about now. I think I check and see if he can do one for me. He made a custom router bit for me years ago. Thanks for the info. I currently have 9-boxes and 3-baskets that I will finish by the first of the week and all will be gone by next week. One 5-year old girl's mom said the girl has a brain tumor. She said the girl is raising funds to help other kids with cancer. I will donate a basket to this girl and see if she has other friends with cancer that I could donate to.

I'm thinking about it and have you tried wrapping acrylic tape one the outside diameter of the bushing? This would make your outside diameter just the thickness of the tape larger. I say acrylic because I know it come in various thicknesses and the adhesive is very strong. It's the stuff they use to mount the Ford or Chevy logo on a car, try pulling one of those off!!!!

Best of luck, bless you and those sick children

 

[kywoodchopper]

Sorry just realized your name isn't Malcolm, that's where your from!

I'm thinking about it and have you tried wrapping acrylic tape one the outside diameter of the bushing? This would make your outside diameter just the thickness of the tape larger. I say acrylic because I know it come in various thicknesses and the adhesive is very strong. It's the stuff they use to mount the Ford or Chevy logo on a car, try pulling one of those off!!!!

Best of luck, bless you and those sick children

I have thought of that. I may try that first. I just made a slightly larger jig for cutting the crosses. I have a drawer full of bushing. Put it on one and leave it there. Then cut and using that one then use a bushing without the tape. Thanks for the info.

 

[kywoodchopper]

I have thought of that. I may try that first. I just made a slightly larger jig for cutting the crosses. I have a drawer full of bushing. Put it on one and leave it there. Then cut and using that one then use a bushing without the tape. Thanks for the info.

I never realized that my name isn't Malcolm. If my mom was still alive I could ask her if she knew that. Shaw! What did you think that wasn't my name?

 

[bfblack]

A machine shop might be more interested in making one guide bushing from scratch of material of their choosing but to your diameter.

 

[harrysin]

Among these guides that I made is the black Makita one to which I added a sleeve which was then turned down to a specific diameter for a special job, long since forgotten. Anyone with a metal lathe would be capable of doing this.

 

[kywoodchopper]

A machine shop might be more interested in making one guide bushing from scratch of material of their choosing but to your diameter.

Yep, I have thought of that.

Among these guides that I made is the black Makita one to which I added a sleeve which was then turned down to a specific diameter for a special job, long since forgotten. Anyone with a metal lathe would be capable of doing this.

I thought of that. I'll see what I can come up with.

 

[pennview]

I am using a plunge router to cut crosses in boards. I have been using a 1/2" spiral carbide bit, but the finish cut leave rough and occasional burnt spots - especially in maple. I've been cutting these crosses in box lids for soup kitchens, churches and assisted living places. I have "Prayer Request" engrave along the cross.

I use a guide bushing that is .625" outside diameter. If I used that for the original cuts then swap out that bushing with one that is say .615" I believe the router bit would just be taking off a tiny bit of wood and clean up the cut.

Years ago I was using a 1/4" router bit and purchased two brass guide bushings. One is .434" and the other is .442". By using the .442" bushing first then by swapping to the .434" with the same router bit it would shave off just a tiny bit of wood. I have no idea where I purchase those guide bushing.

I went to a machine shop today and show them what I was trying to do, but was told they couldn't shave any off the current bushing because there wasn't enough metal there.

I tried using a 1/4" spiral bit with the two bushing that I have (.434" and .442"), but the bit isn't long enough. It is 2 1/2" long, and would require around 2 3/4" to 3" long bit.

Does anyone know where I could purchase guide bushing around 5/8" and another either slightly larger or smaller or a 1/4" spiral bit that is around 3" long?

Here is a photo that I posted earlier showing what I am trying to accomplish.

Thanks folks, Malcolm / Kentucky USA

I'm assuming that you're using a template with 5/8" slots in the shape of a cross for locating and cutting the 1/2" wide cross in the box top. If that's correct, why not use a 3/8" spiral router bit with a 5/8" template guide bushing for the initial cut and then install a 1/2" guide bushing to finish the cut. Together, they should give you a 1/2" wide cross-shaped slot in the box top. That second cut is only taking off 1/16" so you shouldn't get any burning. If you do, don't take the full 1/16" off with that second cut, just do some light skimming passes until you get the full 1/2" wide slot. If this fails, perhaps use walnut for the box top so one doesn't notice any burning.

Also, Harbor Freight sells some spiral cut bits of high speed steel that are a bit over 3" in length -- items 61583 or 93450.

 

[Mike]

When all else fails go back to the basics. You are getting tearout and burning. To get a good cut your bit must be cool, clean, sharp and not moving to fast. Even a very slight build up of resin will make the bit sticky, generate heat and spoil your cut. I use Trend Tool and Bit cleaner; there are other brands of products available and most do a good job.

How many hours using your spiral bit? Odds are it needs to be sharpened. Depending on which brand you are using it may be cheaper to replace it.

Temperature of the bit is important. A small diameter bit will heat up much faster than a larger diameter bit, it also takes longer to clear the chips away. Always use the largest diameter bit you can, 1/2" shank has more mass to dissipate heat than a 1/4" shank bit and tends to be stronger with less vibration. Use the shortest length bit you can to get the job done, again less vibration.

Speed kills. This is affected by the type of wood, how much material you're removing, how much pressure you are putting on your router to move it and the RPM of the bit. Hardwoods require slower cutting speeds than softwoods. Slow down. There are different ways to accomplish this: remove less material, push your router slower and adjust the RPM down.

For your specific situation follow your template using a 3/8" bit as a starter cut then switch to your 1/2" bit as Pennview suggested. You will then be removing less material which means less effort and heat.

 

[harrysin]

When all else fails go back to the basics. You are getting tearout and burning. To get a good cut your bit must be cool, clean, sharp and not moving to fast. Even a very slight build up of resin will make the bit sticky, generate heat and spoil your cut. I use Trend Tool and Bit cleaner; there are other brands of products available and most do a good job.

How many hours using your spiral bit? Odds are it needs to be sharpened. Depending on which brand you are using it may be cheaper to replace it.

Temperature of the bit is important. A small diameter bit will heat up much faster than a larger diameter bit, it also takes longer to clear the chips away. Always use the largest diameter bit you can, 1/2" shank has more mass to dissipate heat than a 1/4" shank bit and tends to be stronger with less vibration. Use the shortest length bit you can to get the job done, again less vibration.

Speed kills. This is affected by the type of wood, how much material you're removing, how much pressure you are putting on your router to move it and the RPM of the bit. Hardwoods require slower cutting speeds than softwoods. Slow down. There are different ways to accomplish this: remove less material, push your router slower and adjust the RPM down.

For your specific situation follow your template using a 3/8" bit as a starter cut then switch to your 1/2" bit as Pennview suggested. You will then be removing less material which means less effort and heat.

WOW, it's good to see you Mike, it's six months since we last spoke. Because of Marlene's poor health I'm her official carer and it keeps me very busy and not really in the mood for chatting, even though I do miss all those LONG chats that we've had over the years. Hopefully you've mastered this new forum layout and will be able to teach me to navigate it as you taught me so many things. I like your new avatar. There aren't many of the old faces on this forum now as you no doubt have noticed. I look forward to catching up with you very soon.

 

[harrysin]

Nudge, nudge, wink, wink!!!