# So how much HP does it take to run a Shaper Bit?

 Forum topic by timbertailor posted 05-08-2015 03:05 AM 1139 views 0 times favorited 11 replies
 timbertailor1594 posts in 1448 days 05-08-2015 03:05 AM I know that it will probably be somewhat reliant on bit diameter, but some minimum numbers would be helpful or more specific info about the effects on speed, etc. -- Brad, Texas, https://www.youtube.com/user/tonkatoytruck/feed

## 11 replies so far

 Andre1873 posts in 1830 days #1 posted 05-08-2015 06:40 AM I have a 1.5 hp Grizzly and find the type of wood, depth of cut and how fast you want to go makes the biggest difference. Profile of cutter heads does make some difference also. Ran quite a bit of Birch through my machine with no problem at all, even doing some in one pass on a 2.5 in. dia. bit. I think the Grizzly machine has a 4.5 in. max dia. capacity. -- Lifting one end of the plank. SirIrb1239 posts in 1254 days #2 posted 05-08-2015 11:06 AM There are a few things to take into acct. spindle size does directly affect the weight of the cutter. So a 1/2” spindle wont happily spin a real heavy insert cutter. Think 3+lbs. Yall correct me if I am wrong. So what is the max cutter weight? You have amount of cut you will be taking. Stick and cope are not the same as crown or a detailed tall base. You have the feed you will be pushing. If you have a powerfeeder you never want it to overfeed the machine hp. So the equation works like this. Heaviest cutter * sq in of cut youre taking + liner feet per second = hp. Ok, that isnt an equation and I am an engineer who failed algebra 5 times not counting high school and never got a college degree. I would say that this like all machines the answer is: you will never have too much hp. As stated above, 1.5 is good. But 3 is better. And 5 will make you smile the happy smile. 7.5 will make you wet yourself. Are you making cabinet doors or crown or handrail? -- Don't blame me, I voted for no one. dhazelton2771 posts in 2320 days #3 posted 05-08-2015 12:54 PM Depends on what you’re going to do with it. Delta Homecraft and old Craftsmans were probably no more than 3/4 – 1 HP. Sharp bits and shallow cuts make that possible. timbertailor1594 posts in 1448 days #4 posted 05-08-2015 01:54 PM I was looking at some of the more intricate bits for crown mouldings. I have a Milwaukee 5625-20 with 3.5HP or something close in my router table already and was wondering if I could use it to do some of these more intricate moldings. I did not want to invest in a bit (and some of them are expensive) only to find out that it would take me more passes than I care to take the time to do vs. just buying it already machined. -- Brad, Texas, https://www.youtube.com/user/tonkatoytruck/feed SirIrb1239 posts in 1254 days #5 posted 05-08-2015 02:32 PM So you have a router/ router table, not a shaper. is this correct? In that case I will exit stage left. -- Don't blame me, I voted for no one. DalyArcher115 posts in 1143 days #6 posted 05-08-2015 04:51 PM I agree with the above. A router is not a shaper. Making doors with stick and cope bits is one thing, running high profile, heavy, large diameter bits is another. Have you considered a molding head cutter for your tablesaw? I’ve not researched these much, but they seem like an interesting addition to the shop. bigblockyeti5137 posts in 1744 days #7 posted 05-08-2015 05:06 PM I too have that Milwaukee router and while as a router it’s very capable, substituting it for a shaper would almost certainly prove disappointing. You may be able to get away with several shallow passes on soft wood that isn’t too wide. Where I worked we had a 7.5hp Invicta shaper with a 1 1/4” 4 speed spindle, and it would swing either a 10” or 12” cutter. It could cut a deep and wide rabbet very fast even in hard wood. It’s just a function of how quickly you want to work. timbertailor1594 posts in 1448 days #8 posted 05-08-2015 05:08 PM I agree with the above. A router is not a shaper. Making doors with stick and cope bits is one thing, running high profile, heavy, large diameter bits is another. Have you considered a molding head cutter for your tablesaw? I ve not researched these much, but they seem like an interesting addition to the shop. - DalyArcher The table saw has about half the power of my router. That seems like a step backwards. -- Brad, Texas, https://www.youtube.com/user/tonkatoytruck/feed timbertailor1594 posts in 1448 days #9 posted 05-08-2015 06:20 PM I too have that Milwaukee router and while as a router it s very capable, substituting it for a shaper would almost certainly prove disappointing. You may be able to get away with several shallow passes on soft wood that isn t too wide. Where I worked we had a 7.5hp Invicta shaper with a 1 1/4” 4 speed spindle, and it would swing either a 10” or 12” cutter. It could cut a deep and wide rabbet very fast even in hard wood. It s just a function of how quickly you want to work. - bigblockyeti Thank you. That is what I wanted to know. I do not plan to dedicate the table router to JUST large bits, just the occasional use of a larger shaper bit for crown mouldings. I will add this to my watchlist and report back my findings. -- Brad, Texas, https://www.youtube.com/user/tonkatoytruck/feed cabmaker1735 posts in 2833 days #10 posted 05-09-2015 02:47 AM Brad……that router on anything more than a 2 1/4 inch crown profile will be sorta like taking a pocket knife to a gunfight. A key factor is the total line of engagement in the material at a given moment. If your not equipped for it, you ll find a large waste factor in crown mold….very large. Not to mention the need for power feed if you want a quality run of any considerable amount that long shaft required will have substantial deflection, that is if you have enough beef to keep the material where it needs to be. Your router bearings will fail prematurely as well. Get a shaper. Shadowrider183 posts in 1233 days #11 posted 05-09-2015 04:22 AM I agree with the above. A router is not a shaper. Making doors with stick and cope bits is one thing, running high profile, heavy, large diameter bits is another. Have you considered a molding head cutter for your tablesaw? I ve not researched these much, but they seem like an interesting addition to the shop. - DalyArcher The table saw has about half the power of my router. That seems like a step backwards. - timbertailor It may seem so but there is more to it than plain HP. The heads he’s talking about will carry a lot more momentum at speed because they are a lot heavier than a big router bit and are turning at a much larger diameter giving them higher surface footage per minute at the cutter tooth. A table saw with a moulding head would cut far better than a router. But does anyone still make those moulding heads for a table saw? I really haven’t looked but may have a use for one if it’s a quality head and various profile cutters are available. I know my 3HP Unisaw would spin any that I’d need.

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