Spoilboard surfacing tool question

[Chuck Keysor]

Very shortly I will need to surface the spoilboard of my PRTalpha 5'x12'. Roughly speaking, a new 1 1/2" diameter planing bit is around $50. Yet a couple of people on past posts have said that they like the Amana surfacing tool with replacable knives. The Amana 1 1/2" bit costs $169. And that includes a set of the 4 sided knives.

So, it looks like if someone throws away their $50 regular planing bits when they go bad, that the $169 bit with four sided blades would be cheaper. But I don't know about sharpening costs and more importantly, the quality of resharpened bits.

As added information: A friend of mine has maybe 40 rough sawn planks of heura crepitans (spelling?) that are 14 inches wide, 8 feet long and 2 inches thick. I have two, and another friend has maybe 10. Flattening these boards prior to further processing is very difficult because of their size and weight. I would like to use my ShopBot to do this type of work on occassion.

Questions:
Is it the better option to buy a conventional planing bit for $50 and just get it resharpened whenever it gets dull? Or are there problems/costs associated with sharpening conventional bits that make buying the Amana RC2250 the logical purchase?

As a guess, what would be a logical number of replacement blades to keep on hand given my intended application?

Thank you, Chuck

[bleeth]

Replacement blades are cheap. Buy em by 10 or so.
Re-sharpening a surfacing type of bit should be no issue if your local grinder is any good.
I use a Whiteside 1 1/4" mortise bit. Cost me $20.00 All I use it for is surfacing. Sharpen once then replace.
If I surfaced wood on a regular basis I would get a different bit.
For surfacing wood (and your spoilboard once you know FOR SURE that your Z is right) Use Paco's surfacing routine. A quick search on this forum will turn it up in a heartbeat.
Which way you go on the bit is personal. All work just fine.
FYI: the reason for using SB's routine for surfacing most often is that the results (hopefully not ridges) will confirm that your Z is good. Pacos just goes back and forth in the x direction so is good for surfacing with the grain. It also does your spoilboard faster than SB's

[jim_rutske]

Chuck, I have opted for a 1.5 inch straight bit from Woodworkers Supply. They are around 35-40 dollars. I am on my second one in a couple years. When it gets a little dull I just take a diamond hand sharpner and put a newish edge on it. Given its large size, sharpening is easy. I not only use it for surfacing the spoilboard but have also used it in flattening/planing rough lumber. My first one got eatin up by surfacing dirty/sandy cedar for a sign. A 'bit' of a lesson there.

[Gary Campbell]

Chuck...
I have surfaced a lot of large lumber pieces over the last few years. My first was a 3' by 4' oak table top. The 1 1/4 surfacer I had lasted almost thru the first pass. Many woods, especially the exotics, are oily, which gum the bit slightly, which creates heat, which immediately dulls the bit.

That is why I switched to the Amana 2 1/2" insert cutter ($250+) They are a good tool, and like all good tools, are not cheap to buy, but in the long run much cheaper than soldered carbide bits. The insert bits also seem to have a cleaner angle of attack than the ground bits and shear the wood much better. For spoilboard surfacing it doesnt make a whole lot of difference, other than time. The big bits cover ground a whole lot faster. Like Dave says, your Z axis must be perpendicular to the table in both directions.

[bleeth]

Hey Gary:
You have always run PRS's. I'm not sure that big puppy would be right on a PRT. As you know they are not nearly as smooth and the huge width of that one could be an issue on a PRT gantry. I would keep it to a smaller diameter.
(Note to GC: Issue spoken about earlier solved-fix was too easy-time to Black Viper the thing.)

[myxpykalix]

Chuck,
I guess you need to ask yourself how much use you will give one of these bits in order to figure out what is best for you. If you are like me and only use the bit to surface your table and/or a few other occasions I would go for the magnate 1.5" bit for $22.57
http://www.magnate.net/index.cfm?eve...roup&theID=136
Because it will last you long enough for your needs.

However if you are like Gary or Dave and need to use it all the time then you might want to go with some of their suggestions. I just couldn't see paying $160.00 for a bit that you use occasionally.

[srwtlc]

I've used a 1.5" Jesada for several years for the spoilboard and some surfacing of wood. I've had it sharpened several times and although it may not be 1.5" anymore, it still has carbide to spare for more sharpening. Sharpening cost for me here is about $5.50 each time.

I have a 1.5" CMT waiting it's turn.

[beacon14]

I'm with Gary, and yes Dave, on my PRT (alpha) I use the 2 1/2" insert bit from Amama. Mine pre-dates the newer four-insert variety and has just the two inserts. I also use it to surface hardwoods including exotics and can usually go up to 1/8" deep per pass with a 2" stepover at 4ips, sometimes a little slower in difficult or hard grain or wood with knots. They make different inserts for hardwoods and softwoods (like spoilboards) but I've just been using the hardwood inserts lately and my spoilboard doesn't seem to mind. I re-surface .01" deep at 8ips.

My Z axis is deadly accurate - there are no tactile ridges on my surfaced spoilboard.

Once you are re-surfacing every couple of weeks the difference between a 1" stepover and a 2" stepover saves a lot of time over the course of a year. But you do have to be real careful not to drop them on the floor or run into such things as your brand new pneumatic stops.

I also think we do less sanding with the surface left by the insert cutter than we used to with the planer bit, and it's nice to be able to put fresh inserts in for the last critical pass instead of making the last pass when the bit is at its dullest.

[frank134]

I am also with Gary,Dave and David. I think the amama 2 1/2" bit is great. But I learn something new here again. I didn't know you could get differance bit or cutter for it. Thank David for the info. I surfaced a lot of hard white maple with it. all of it trun out great.

[waynelocke]

I use a Hersaf 2" insert cutter, http://www.hersaf.com/shop/index.php...rt/0/subid/14/, which now retails for about $130 plus about $10 for the arbor. I have used this for years. It works great.