Dr.Jass
Pastor of Muppets
Since I had a bunch of pushrod clearancing to do on the W2 heads, today seemed a good time to finally break out the Foredom flex-shaft tool I bought myself last year. If you're not familiar with Foredom, their tools are pretty big in the woodworking world. It's an electric motor connected to a super-duty "speedometer cable" with a handpiece that accepts bits, same as a die grinder. Speed control is handled by a foot pedal, leaving your hand(s) free to concentrate on keeping the bit where it needs to be. The KTXH-440, which is the one I bought, has a 1/3HP motor and a square-drive shaft. It is the "industrial" model and the only one they recommend for regular use on metals. The lesser models use a lower-power motor and a different cable that is not designed to withstand repeated metal work. They make the thing; take their advice.
First impression upon unboxing? "Wow, this seems really well made," which is very good considering the price. The handpiece appears to be billet aluminum with steel fittings. It's got a quick-release collar at the rear where the cable attaches. There are three collets included: 3/32", 1/8", and 1/4" and the handpiece itself is fairly lightweight, yet very solid-feeling in the hand. The collet nut is amazingly low-profile. The cable is very heavy, about twice the size of an actual speedometer cable in size, with an industrial rubber jacket. It's 63" long and comes attached to the motor. It connects very solidly to the handpiece, and removal is quick and easy with the quick-release collar (don't let it catch skin!). The motor is very small considering its power rating, thanks to being a permanent-magnet type, but it's heavy for its size. It will only plug into the speed controller; the connection is similar if not the same as a PC power supply's. There's a bracket for hanging the motor, or you can buy a stand (I just hung it off the handle on my drill press for today). The foot controller is all metal and looks and feels like industrial equipment.
I installed a rasp--might as well use the most-wicked bit I'll ever install right out of the gate--and connected everything. The foot control has about 1" of travel. It's very sensitive but also very linear; you can run slow enough to watch the teeth go around. Pressing the pedal to the floor, I was impressed by how quiet it is, but was also immediately sure I'd blown a bunch of money on this thing: "This doesn't run nearly fast enough." Only one way to find out, right? Putting rasp to cast iron, I discovered that not only is the speed pert-near perfect, this thing does not slow down. Ever. If you slow it down with the pedal, that's one thing but it's not happening otherwise. "Torquey" does not seem an adequate term; if you're used to die grinders, be prepared for a treat. Even at low RPM, good luck making it stall. I was very impressed by the power. Despite the lower RPM, you give up nothing to the air tool in terms of efficiency. In fact, I'd still be out there had I used a die grinder, probably waiting for the compressor to build pressure... again.
The cable is less obtrusive than an air hose for some reason, and nearly as flexible. An electric die grinder's cord is better, but a good electric die grinder also weighs a ton. After a minute you don't realize the cable's even there. The size of the handpiece and the low-profile collet nut means you can go places any other type of grinder can't reach. I hogged out eight pushrod holes today in pretty short order and never had to change to a longer bit. However, the rasp did pop out a few times. I don't know if that's because my cheap eBay bits are slightly undersize or if it's a failing on Foredom's part, but in its defense I was leaning pretty hard on it--half trying to get done, half seeing if I could slow the thing down one iota (I could not)--and a rasp is a high-vibration tool.
Speaking of vibration, it's smoother than a die grinder. I got as far as I did today because my carpal tunnel never started to bother me, despite using the rasp. With the sandpaper rolls I used to dress the pushrod holes, vibration was nearly non-existent. I'd only planned to do a few holes, then come back inside. I even started to make my way to the house once, but decided to dress one more hole. The next thing I knew, I was done with that head. I didn't feel beat up like I normally do after a couple of hours' worth of porting: Less vibration and the handpiece weighs about half as much as an air grinder. I didn't have to use my hand to start, stop, or try to vary the speed, although I tried to do just that several times--force of habit.
The biggest reason I bought it was noise, and it did not disappoint. It's quiet, maybe 1/3 as loud as an air grinder but probably less, not including the compressor running... again. The bit makes more noise than the tool does, which is pretty impressive. I had the stereo at a sub-obscene level and could hear the music just fine while I was working. I had to run the stereo WFO with an air grinder, and forget hearing it once the compressor started... again. Much like myself, the compressor was spared a ton of wear and tear today thanks to the Foredom.
After the amount of grinding I did just on Agnes' engine so far--clearancing for roller lifters, smoothing oil block and head drainbacks, gasket-matching heads, extensive porting on the intake, etc.--I really wish I'd have known this thing existed back in 2017. I'll still use my air grinders when it's quicker than setting this up, but they'll get a lot less use now. I didn't hate grinding today; in fact I was eyeballing those ports thinking I would go after them before I install the heads. It's that nice to use.
PROS: Virtually everything: power to spare, quiet, nearly vibration-free depending on the bit, lightweight, compact, and every component feels overbuilt. Less operator fatigue in every aspect. No waiting for the air compressor nor hearing it run... again.
CONS: The bit fell out a few times, which might've been the bit's fault. Finding a good place to put the motor; buy or make a stand. Don't let the motor fall because the permanent magnets could crack. The price; this thing will currently set you back about $500 once it's at your door.
Yeah, it's expensive. It's also worth every penny if you do a lot of grinding. I'll do a lot more now, willingly.
First impression upon unboxing? "Wow, this seems really well made," which is very good considering the price. The handpiece appears to be billet aluminum with steel fittings. It's got a quick-release collar at the rear where the cable attaches. There are three collets included: 3/32", 1/8", and 1/4" and the handpiece itself is fairly lightweight, yet very solid-feeling in the hand. The collet nut is amazingly low-profile. The cable is very heavy, about twice the size of an actual speedometer cable in size, with an industrial rubber jacket. It's 63" long and comes attached to the motor. It connects very solidly to the handpiece, and removal is quick and easy with the quick-release collar (don't let it catch skin!). The motor is very small considering its power rating, thanks to being a permanent-magnet type, but it's heavy for its size. It will only plug into the speed controller; the connection is similar if not the same as a PC power supply's. There's a bracket for hanging the motor, or you can buy a stand (I just hung it off the handle on my drill press for today). The foot controller is all metal and looks and feels like industrial equipment.
I installed a rasp--might as well use the most-wicked bit I'll ever install right out of the gate--and connected everything. The foot control has about 1" of travel. It's very sensitive but also very linear; you can run slow enough to watch the teeth go around. Pressing the pedal to the floor, I was impressed by how quiet it is, but was also immediately sure I'd blown a bunch of money on this thing: "This doesn't run nearly fast enough." Only one way to find out, right? Putting rasp to cast iron, I discovered that not only is the speed pert-near perfect, this thing does not slow down. Ever. If you slow it down with the pedal, that's one thing but it's not happening otherwise. "Torquey" does not seem an adequate term; if you're used to die grinders, be prepared for a treat. Even at low RPM, good luck making it stall. I was very impressed by the power. Despite the lower RPM, you give up nothing to the air tool in terms of efficiency. In fact, I'd still be out there had I used a die grinder, probably waiting for the compressor to build pressure... again.
The cable is less obtrusive than an air hose for some reason, and nearly as flexible. An electric die grinder's cord is better, but a good electric die grinder also weighs a ton. After a minute you don't realize the cable's even there. The size of the handpiece and the low-profile collet nut means you can go places any other type of grinder can't reach. I hogged out eight pushrod holes today in pretty short order and never had to change to a longer bit. However, the rasp did pop out a few times. I don't know if that's because my cheap eBay bits are slightly undersize or if it's a failing on Foredom's part, but in its defense I was leaning pretty hard on it--half trying to get done, half seeing if I could slow the thing down one iota (I could not)--and a rasp is a high-vibration tool.
Speaking of vibration, it's smoother than a die grinder. I got as far as I did today because my carpal tunnel never started to bother me, despite using the rasp. With the sandpaper rolls I used to dress the pushrod holes, vibration was nearly non-existent. I'd only planned to do a few holes, then come back inside. I even started to make my way to the house once, but decided to dress one more hole. The next thing I knew, I was done with that head. I didn't feel beat up like I normally do after a couple of hours' worth of porting: Less vibration and the handpiece weighs about half as much as an air grinder. I didn't have to use my hand to start, stop, or try to vary the speed, although I tried to do just that several times--force of habit.
The biggest reason I bought it was noise, and it did not disappoint. It's quiet, maybe 1/3 as loud as an air grinder but probably less, not including the compressor running... again. The bit makes more noise than the tool does, which is pretty impressive. I had the stereo at a sub-obscene level and could hear the music just fine while I was working. I had to run the stereo WFO with an air grinder, and forget hearing it once the compressor started... again. Much like myself, the compressor was spared a ton of wear and tear today thanks to the Foredom.
After the amount of grinding I did just on Agnes' engine so far--clearancing for roller lifters, smoothing oil block and head drainbacks, gasket-matching heads, extensive porting on the intake, etc.--I really wish I'd have known this thing existed back in 2017. I'll still use my air grinders when it's quicker than setting this up, but they'll get a lot less use now. I didn't hate grinding today; in fact I was eyeballing those ports thinking I would go after them before I install the heads. It's that nice to use.
PROS: Virtually everything: power to spare, quiet, nearly vibration-free depending on the bit, lightweight, compact, and every component feels overbuilt. Less operator fatigue in every aspect. No waiting for the air compressor nor hearing it run... again.
CONS: The bit fell out a few times, which might've been the bit's fault. Finding a good place to put the motor; buy or make a stand. Don't let the motor fall because the permanent magnets could crack. The price; this thing will currently set you back about $500 once it's at your door.
Yeah, it's expensive. It's also worth every penny if you do a lot of grinding. I'll do a lot more now, willingly.
Honestly, that's the first time the air has started for anything but the blow gun since work began on these heads. There simply hasn't been need for the air grinders.