Changing Drill Press to VFD. HELP

[Jerry Hillenburg]

I bought a like new Powermatic 1150 VS serial #8615V167 in 1993 and it served me well until 2005 when the drive sheave assembly was damaged beyond repair because of a loose bolt. I patched it up and it runs, but I cannot adjust the speed and it is very noisy. It is not the most used machine in my shop, so for 7 years I have used it with no speed adjustment along with hearing protection. It does what I need it to do but it is not a joy to use.

I have decided to do something about it. I really was not interested in rebuilding so I went drill press shopping. There is NOTHING new out there under $1500 that can possibly compare to my 1150. This DP has had a gentle life in my cabinet shop - very little use. The way I see it, I have to get interested in rebuilding.

In another thread discussion ( http://www.sawmillcreek.org/showthread.php?188655-Powermatic-1150-VS-Drill-Press-Rebuild-HELP&p=1949868#post1949868 ) Contributor Van Huskey suggested that I change my OEM variable speed to a step-cone sheave setup making it a standard step-cone speed adjustment THEN add VFD.

PLEASE, help me with the VFD - I know absolutely nothing about VFD. What specifically do I need? Your advise will be greatly appreciated.

I have a new in the box Baldor 3hp 1725rpm 3ph motor that is the same physical size as the ¾ hp on the DP (see pictures) - will it work for my application?

[Van Huskey]

The 145T motor will fit I THINK... That is an excellent motor if it works. Don't let anyone question the high horsepower since the belt would slip before it could send all 3hp and the 1150 is built like a tank anyway. It is 1725rpm which is perfect. I would suggest the 3hp Teco 50 drive. I usually recommend factorymation but they haven't had the 3hp in stock for a while, heres one source: http://dealerselectric.com/item.asp?cID=28&scID=165&PID=737

One thing to keep in mind is you don't want to run it at low speed for a long time, the fan that provides cooling will also slow down... DPs tend to only be run for a few minutes at a time so it doesn't usually become an issue. At lower speeds the motor powered by the VFD will keep constant torque down to probably 175 RPM or so BUT HP will drop off BUT with a 3hp motor you probably will never notice an issue. By having such a high HP motor you will have far less to worry about.

At this point get the drive train worked out and make sure the motor will fit. Once this is done it will just be a matter of getting the VFD and wiring it up. You can use the on off switched wired through the VFD's low voltage auxillary circuit and I would think it was cool to put a 10k ohm pot attached to the current VS crank which would allow you to control the speed just like you always did (less effort to move though). Understand you want to wire the VFD directly to the motor (no disconnect or on/off between them). Any on/off will be handled by either the push pad on the VFD or like I said a switch wired to the aux inputs on the VFD. When you have a better idea exactly how you want to control the motor and if this motor will fit and which VFD you are going to get the more specific we can be in wiring it up.

[Salem Ganzhorn]

I have the same DP with a 3/4 HP 3phase using a Teco fm50 VFD. It works very well. I agree mostly with Van: fix the drive train first! If you have lived with a single speed this long maybe it isnt worth fixing the reeves drive. But I would at least look at OWWM before giving up.
Salem

[Richard Wolf]

God, I want to know how people keep their shops so clean?

[Van Huskey]

God, I want to know how people keep their shops so clean?

I don't have a problem keeping a shop clean, my problem is with the house.

[Geoff Crimmins]

A also think the 145T motor will fit. I expect you'll find it has a 7/8" diameter shaft, while the 56 frame motor probably has a 5/8" shaft. (I believe Powermatic made sheaves to fit both shaft sizes.) Redmond Machinery probably has used sheaves if you want to repair the Reeves drive. If you want to use the VFD then that won't be necessary. A VFD is fairly simple to wire, but it take a while to wade through the instruction manual to program it. BTW, you are correct that you have an excellent drillpress that is well worth repairing.

[Mike Heidrick]

I think I would choose a Sensorless Vector constant torque model for a drill press. Here is the JNEV-203-H1 from Teco at $215 http://dealerselectric.com/item.asp?cID=28&scID=165&PID=370

Hitachi also makes a nice one.

Also think about the enclosure you will mount it in. There are Nema 4 enclosures for these or you can buy it with one right from the start - many have speed control POTS, direction, and disconnect switchs built right in. Plus you do know it will be a 220V tool after this 3hp and VFD upgrade (maybe it was before?).

[Jerry Hillenburg]

Wow, so much to digest.

Mike the DP is wired 220v single phase now. I plan to keep it 220 single phase but my shop does have three phase.

Mike, you suggest the Vector J NEV-203-H1 from Teco for $215 - it has only single phase input. Van, you suggested the Vector FM50-203-C from Teco for $184 - it has single or three phase input. It would be nice to have both single and three phase input since I have three phase. Aside from the phase input, what is different in these two? Is there another model that combines the advantages of both?

Mike you also mentioned an enclosure for the drive. Are the plastic encasements they come in insuffeciant to protect them? If you put them in a Nema 4 (dust/water tight) enclosure how do you use the control panel?

Geof, no doubt about it, the 1150 is a DP to be proud of and I am going to make mine better with VFD. The motor is a ⅞" shaft. Will try to get OEM step-cone sheaves from Redmond Machinery. If they are crazy expensive I will talk to Grainger or McMaster Carr.

Salem, As of today, I am now a member of OWWM (http://www.owwm.org/viewforum.php?f=1). I plan to spend some time there.

[Van Huskey]

I think I would choose a Sensorless Vector constant torque model for a drill press. Here is the JNEV-203-H1 from Teco at $215 http://dealerselectric.com/item.asp?cID=28&scID=165&PID=370

Hitachi also makes a nice one.

Also think about the enclosure you will mount it in. There are Nema 4 enclosures for these or you can buy it with one right from the start - many have speed control POTS, direction, and disconnect switchs built right in. Plus you do know it will be a 220V tool after this 3hp and VFD upgrade (maybe it was before?).

Mike correct my logic but I don't see the need for a sensorless vector drive in his application. The FM50 will give constant toque down to 6hz. The vector drive will adjust the output via motor feedback to keep the RPM constant under load but I don't see how that is needed here. He is using a motor with 4 times the HP of the original (I think it was 3/4hp) and more than the single blet drive train will carry anyway. The motor will slow from synchronus speed (1800) to plate speed (1725) at 3hp so it is unlikely that after gearing the bit would slow more than 20-30 rpm at 3hp and in practice 10-15 rpm at the point the belts would slip, I just don't see that loss of speed at SERIOUS HP requirements being an issue here. That all said if he wants a speed pot right on the drive instead of using the up/down buttons or installing a remote pot then that would be a good low cost drive for that feature.

As for the enclosure a NEMA 4 would cost more than the drive itself, plenty of people just mount them with their "whimpy" IP20 rated chassis right to the press.

[Van Huskey]

Wow, so much to digest.

Mike the DP is wired 220v single phase now. I plan to keep it 220 single phase but my shop does have three phase.

Mike, you suggest the Vector J NEV-203-H1 from Teco for $215 - it has only single phase input. Van, you suggested the Vector FM50-203-C from Teco for $184 - it has single or three phase input. It would be nice to have both single and three phase input since I have three phase. Aside from the phase input, what is different in these two? Is there another model that combines the advantages of both?

Mike you also mentioned an enclosure for the drive. Are the plastic encasements they come in insuffeciant to protect them? If you put them in a Nema 4 (dust/water tight) enclosure how do you use the control panel?

Geof, no doubt about it, the 1150 is a DP to be proud of and I am going to make mine better with VFD. The motor is a ⅞" shaft. Will tryo try to get OEM step-cone sheaves from Redmond Machinery. If they are crazy expensive I will talk to Grainger or McMaster Carr.

Salem, As of today, I am now a member of OWWM ( http://vintagemachinery.org/ ). I plan to spend some time there.

Teco makes the same drive with 3 ph input, there are plenty of 3ph & 1ph input Vector drives but as I said I do not think you need it, but if you decide to get a vector drive instead of just a V/Hz drive like the FM50 know there are PLENTY of choices, but I am not sure if any are as cheap as the Teco Mike linked to.

They make NEMA 4 enclosures to fit most all these drives with full use of the front controls but they are EXPENSIVE the 3hp Teco I mention is ~185 with its native IP20 protection and near $500 with a NEMA 4x enclosure. Some people put them in large metal boxes (need about 4 times the cubic area of the drive itself for cooling) and run all the controls remotely, in this case all you need is on/off and VS, those can be run with small gauge wire like 18g thermostat wire. Again most of the DP setups I have seen use nothing more than the IP20 case they come in, your shop looks like it has good dust collection...

If you want to get in touch with a large group of VFD gurus go to Practical Machinist, they have an entire forum devoted to phase conversion and VFDs. You will get a lot of varied opinions though.

This looks duanting and you can spend all your extra time for 2 lifetimes learning about VFDs and motor control BUT you will see very quickly that all you NEED to know to do this conversion will come very quickly and painlessly. The drivetrain conversion will probably take more work and thought. My first thing would be to compare the cost of fixing the Reeves drive vs going VFD.

[Mike Heidrick]

Its not that the chasis is whimpy, its is protecting the drive from dust. No IP20 drive should ever be mounted outside an enclosure in a dusty environment. Folks do it all the time yes, but that does not make it right. An enclosure that has 2" of space around the drive is sufficient.

All controls can be remote mounted.

The loss of hp at low speeds would be the concern and why I recommended . Plenty of stories on PM and even Alan on woodnet has had issues at slow speeds with his setup. Again feel free to do what you need to. Just know the speed ratings you need to keep the available hp.

www dot forums.woodnet.net/ubbthreads/showflat.php?Cat=&Board=UBB2&Number=5797783&page=20&view=collapsed&sb=1&o=&fpart=1

If you have 440V 3 phase then search (#1708) Bonfiglioli Vectron VFD 3Phase 3HP 6.5am 2.2kw SYN10 T 400 09 AF NEMA4X on ebay. I use one of these on my bandsaw feeder (mine is 1/2hp though). They are awesome. $270. Awesome deal for ip65 nema4 enclosure.

[Van Huskey]

Mike, I certainly wasn't saying I was right just what my thoughts would be.

I didn't mean the standard IP20 chassis was pyhsically weak just weak on protection, basically open air with regard to dust, maybe worse than that since it has active cooling. My thoughts were based on almost every VFD I have seen in a woodshop was sans enclosure and I haven't seen anyone attribute a failure to environmental conditions but it certainly could happen.

Regarding the torque/hp. Correct me if I am wrong! The FM50 is rated for contant torque to 6hz so constant torque down to 175-180 rpm at the motor depending on load. The problem isn't torque it is HP as HP will drop in a linear fashion with RPM so at 175 rpm the motor will only produce .3 HP. Lets say we want to keep HP at or above the stock 3/4hp since Jerry never said he needed more HP than he had. As long as we keep the rpm of the 3hp motor at 432rpm or above it will produce the same HP as his stock motor (or more). So we need to never go below 15hz to keep the 3/4hp. The vector drive (and all cheaper vector ones) use an internal sensor to monitor the load and adjust the output to keep rpm constant (very important in some applications) and would help keep the motor from bogging in a DP application if the drilling becomes too hard. However, Jerry is planning to put on a 3hp motor with 4 times the HP of his stock motor. This motor will drop to 1725rpm at 3hp (not factoring in the 1.15 service factor). Moving into a practical example lets say Jerry is using a mechanical 4-1 reduction at 60hz the motor will be running 1725rpm (or a little more with less than full load) and the spindle will be at 432. (Low speed stock on the 1150 is 400rpm) At 432rpm he would have 3hp (but the single belt won't transfer that anyway). Now, drop the frequency to 15hz and your spindle is at 107rpm and you are getting 3/4hp if Jerry trys to stop his spindle like Alan with his hand he will get wrapped around the DP! Jerry will have a 4-1 electronic range without dipping below his normal HP, if he sets up his low speed at say 250 rpm he could run from 250 to 1000 rpm without touching the belt and never have less than 3/4hp (and never go over 60hz, so he could even extend the range). My point being Alan and the other people that have low HP at low speed didn't get a motor with 4 times the stock HP, that fixes a LOT of the potential issues. Many people buy a 3ph DP and just add a VFD then they end up with miniscule amounts of HP at low speed, even a vector drive isn't going to do much for the large difference.

Again I could be completly off base (wouldn't be the first time) but Jerrys massive motor (by DP standards) gives him all kinds of breathing room.


The most vulnerable part of my proposition is how much torque is actually needed for the bits at slow speed, in my example the mechnical reduction increases the torque by a factor of 4, is this enough??? Then again with just two step cone pulleys instead of the normal three in a non-VS DP what is the maximum mechanical reduction, it may be closer to 3-1, then all the numbers need to be run again. Much easier when you have a standard 12-16 speed drill since you are probably going to be able to get up to 10-1 mechanical advantage.

[Rick Fisher]

A 3hp Motor on a Drill press won't cause any problems due to the configuration of the sheaves and pulley's .. The middle speed will have the most power.. on the fastest and slowest speed, there will be little change in power compared to a stock motor ..

The maximum power that motor can transfer will be limited to the size of the smallest sheave.

A 2.65" Sheave will transfer 1.7 hp in a 2 spindle application ..

The thing is .. the Drill press was designed to work well with a smaller motor and the sheaves will transfer all the power the Drill press needs.. The rest is just electron's and maybe belt wear.. lol

My point is .. if your going to skip the stock pulley system to change speeds, leave it on the middle section, avoiding the smallest sheaves... You will get a bit more power ..

If you put a fancier VFD on the press and run it on the slowest or fastest speed, say the smallest sheave is 1.35" .. your motor losing 66% of its power would still have more power than needed.

[Mike Heidrick]

It sure sounds good and worth a try IMO.

[John Coloccia]

re: VFDs

If you're going to go this route, I suggest getting one with a knob.

I do wonder, though, why not just fix the Reeves drive?

[Van Huskey]

re: VFDs

If you're going to go this route, I suggest getting one with a knob.

I do wonder, though, why not just fix the Reeves drive?

I think the switch from fixing the Reeves drive to VFD can from the potential sourcing of the parts and the costs involved, it may be cheaper to go VFD since he has a brand new 3ph motor.

I agree with getting a VFD with a rotary speed pot on the face UNLESS he decides to do the speed control and on/off remotely which is what I would do. I still think connecting the pot to the original speed control and using the original on/off button would give a very clean install, you wouldn't even know it was VFD driven.

[Jeff Duncan]

How much of the drive was damaged? Not for nothing but there are a ton of parts for 1150's on e-bay....I would at the very least compare the costs. Your going to have to replace the drive parts anyway to use that new honking 3 hp motor. Plus your going to have to do all new wiring. Just seems like your going to have to do/spend as much to reconfigure it as you would to just fix it?

good luck,
JeffD

[Jerry Hillenburg]

I have searched every where, Redmonds, Grainger, McMaster Carr - cannot find a step-cone sheave to fit the 3hp motor's 7/8" arbor to convert the DP to a step-cone speed adjustment. It is unlikely that I can use the 3hp motor because of that.

I did find the parts I need to repair the VS @ $250. I do not know what to do. Any ideas?

The spec sheet in the parts manual list two motor options, an 1800 RPM with a speed range of 450-4800 and a 1200 RPM with a speed range of 300-3200. The DP is the same for either motor. I can buy a new 1200 RPM motor thus getting the desired lower RPM and it's 3200 RPM high end would be ok.

[Van Huskey]

The arbor isn't an issue Baldor/Maska makes them but they ain't bottom barrel pricing but you only need one, the other side can be a cheaper one since I assume it is a more standard bore.

http://www.electricmotorsite.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=EMS&Category_Code=pul_step_0875

I didn't shop for price just verified they exist.

[John Coloccia]

Personally, I would start by repairing the drive. Later on, you can always add that 3 phase motor you have and a VFD if you want it to go slower than the standard drive will go....or replace it with a slower motor. I vote for keeping it simple, though, if the goal is to have a working, VS drill press without much figurin' :)

[Van Huskey]

You know at the $250 to fix the DP I am with John. I would fix the Reeves drive and if you feel you need the slower speed just change the motor to a 1200 rpm but you may find the price of 6 pole motors make using the 3ph 1725 and a VFD more attractive.

[John Coloccia]

I'm jealous. That's a nice, solid DP, back when they made a good DP. It's shocking how poor their new ones are. Grab any new one at your local tool store, bring the quill down a couple of inches, grab the collar and wiggle it. Try not to laugh too loudly. One thing I'll give to the Delta 18-900 is at least it's tight when it's new...it won't be in 5 or 10 years, but for now at least.

[Van Huskey]

I'm jealous. That's a nice, solid DP, back when they made a good DP. It's shocking how poor their new ones are. Grab any new one at your local tool store, bring the quill down a couple of inches, grab the collar and wiggle it. Try not to laugh too loudly. One thing I'll give to the Delta 18-900 is at least it's tight when it's new...it won't be in 5 or 10 years, but for now at least.

Before the 18-900 came out and made it somewhat a moot point I checked a dozen or more PM2800 and some were actually very tight, some were as you mention very loose. Although I don't like every bit of the design I would buy one if it was tight. I am interested in the rumors of a new/upgraded DP from them, maybe some info at IWF.

I REALLY want a PM1200 but they are never cheap and crated they are over 700# so shipping makes the deal even worse. I may just suck it up but I can't really justify the usual price for these...

[Jerry Hillenburg]

I cannot believe how focused I have become on this.

The tide seems to have turned on this post to fixing the Reeves drive.

Advantages of fixing Reeve drive;
1. Simple - no electronics to go wrong.
2. I will never have to adjust step pulleys to get from 450 RPM to 4700 RPM
3. Less time involved.
4. Can keep my 3hp motor for another machine.
5. I can install VFD or 1200 RPM motor later to get below 450 RPM

Disadvantages of fixing reeve drive;
1. My low speed will only l be 450 RPM.

I agree that fixing the reeves drive is the way to go.....just bought the parts to fix Reeves drive.

[Van Huskey]

I think that is the best idea for now! BTW where did you get the parts, if it wasn't Redmond (I would be suprised if you have already heard from them) I would like to know the source.

[Jerry Hillenburg]

Van, I got them from an Ebay store called T-Bone Machine. www.ebay.com/itm/130682661006?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com/itm/130682661006?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649) At the same time I purchased a table elevator that obviously will fit the groove in the table side we were talking about on another post (see picture). www.ebay.com/itm/130682679955?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com/itm/130682679955?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)


I have an Ebay store - my niche is stainless steel disconnect switches. - http://stores.ebay.com/Safety-Switch-Store-and-More -

When selling on Ebay, you need a niche. Parting out machinery and selling on Ebay would be a great niche for someone who knows machinery. I just paid this guy $473 for parts from a DP he probably bought at an industrial auction for less that a $100, and he still has more parts to sell off it!

[Jeff Duncan]

I was under the impression that the motor was OK, just the drive needed fixing???

If you have to replace the motor you may have more options? My version of the 1150 features 3 speed ranges based on motor....a 1725 rpm motor will deliver a low speed of 475, 1100 rpm for 330, and a 900 rpm motor will deliver a really low 238 rpm's. I don't know if they changed motor mounts over the years, but if not you should have the same range I would guess??? Now I can't think of many, well any, things you need to drop below 475 rpm's for....but maybe you have some specialized type of work for which it is important? If so you may have other options anyway;)

good luck,
JeffD

[Jerry Hillenburg]

My motor is ok and it is just like any other 3/4hp 1725 RPM motor. The VS sheave above the quill needs replaced.

Can you post picture of your motor and the switch? That would be nice. I have no special need to drop below 475 RPM, but it would be nice to have.

[Van Huskey]

There are a lot of machines that get parted out! The margin is good BUT you will end up with some stuff that never moves so you have to make it on the high demand stuff. Glad you found your stuff!

[Geoff Crimmins]

I just remembered that the last few years the PM1150 and 1200 were made Powermatic eliminated the Reeves drive and used a VFD on the variable speed versions of these drill presses. It seems like the VFD was used with 2-step pullies, but you could check a manual on vintagemachinery.com to be sure. I wonder if Powermatic would still stock the 2-step pullies.

[Jerry Hillenburg]

Geof, You are right - thanks for pointing that out. OWWM has a 2004 manual for the VFW machine; http://www.vintagemachinery.org/pubs/detail.aspx?id=3315 According to the manual they made two models in 2004; the 1150A with the normal step pulley, and a VFD model with three step pulley. The speed range on the VFW was, low 150-700, mid 400-1600, high 1050-4200. I wonder why they discontinued them. It seems every time a company gets bought out, the products they are famous for disappear or cheapens.

For my drill press I have ordered used OEM parts for the repair of the OEM variable speed setup, so for my DP, VFD is a moot point unless I decide to use the VFD on my VS to get below 450 RPM sometime in the future.

[Jerry Hillenburg]

I never heard of VFD until a few days ago. Boy have I gotten an education! At this time my DP's variable speed will repaired to OEM condition. At some point in the future I may put VFD on it in conjunction with the OEM variable speed to get below 450 RPM.

For all you that are confused and trying to understand VFD, go to Alan Schaffter's post, http://www.sawmillcreek.org/showthread.php?188674-Changing-Drill-Press-to-VFD-HELP&p=1950645#post1950645 Also check out, http://www.dealerselectric.com/page.asp?id=24 for Industrial Equipment Sales FAQ on VFD. If I had these two links at the beginning of my VFD education, life would have been a lot easier!

[Mike OMelia]

Re: fixing Reeves drive

I was thinking the same thing. Would that not be the most cost effective approach?

Mike

[Mike OMelia]

Btw, I've seen a pro mechanic repair a Reeves drive once. It's not on the simple (or safe) end of the repair spectrum, lots of spring forces to control, but it can be done.

Mike

[Alan Schaffter]

Here is a copy of my post to Jerry's other thread:

One big consideration, what do you drill and how often. Are you a tinkerer like me who will be drilling all types of wood and all types of metal? That can require a lot of belt changes and significant spindle speed range- 250 - 3000 RPM. It is not all that easy to get with a VFD. VFD's control speed by controlling the frequency of the line voltage. Some have a range of 0 Hz to 200 Hz, while some will go up to 400 Hz. But at low RPM induction motors loose Hp. Many motor manufacturers recommend against going below 20% rated RPM (345 RPM or 20% of 60 Hz = 12 Hz).

You will notice most (all?) commercial lathes that have VFD's also retain mechanical gearing, for a number of reasons- motor hp varies with RPM and so is considerably less at low speed. Motor cooling is also reduced during low RPM. Just think about what this does to a lathe motor when trying to rough a large, heavy bowl blank! With my initial gearing and VFD setting I could easily grab the spindle chuck and stall the 1.5 hp motor on my drill press.

First lets do an example with a VFD, a 1725 RPM motor, and 1:1 gearing via V-belt.

For a spindle speed of 250 RPM (typical low end RPM for cutting circles, larger Forstner bits, etc. in hardwood according to the Wood Magazine drill bit speed chart at this link (http://www.woodmagazine.com/woodworking-tips/techniques/drilling-boring/drill-press-speed-chart/)), the motor will be turning at only 250 RPM, 14.4% of rated its 1725 RPM (250/1725). The VFD will therefore need to put out 14.4% of 60 Hz- only 8.7 Hz! Hmmm, 250 RPM is less than the recommended minimum for that motor. We may want to rethink that after we see what happens at the upper end.

For a typical upper end spindle RPM of 3000, the motor will need to run at 3000 RPM or 1.7 times its rated RPM of 1725. The output of the VFD will need 104 Hz. That is not too bad. Motors don't have trouble over-speeding. Cooling is actually better, but it will reduce bearing life and put out more noise.

But we need a lot more oomph at low RPM, especially if we want to drill large holes or use large Forstner bits in hardwood, or drill large 1/2" - 3/4" holes metal! So lets change the V-belt gearing to 1:3 so motor RPM is 3 X spindle RPM- 1725 RPM motor speed = 575 RPM spindle speed.

To get the spindle down to our low-end speed of 250 RPM we would need the motor to turn at 750 RPM or 43% of its 60 Hz rating (VFD at 26 Hz). Now that sounds better, well within the capability of the motor and the VFD, and low RPM HP is greatly improved. But lets see what happens at the upper end.

To turn the spindle at 3000 RPM the motor would need to spin at 9000 RPM!!!! Yikes! 520% of its rate RPM. No sweat for a universal motor like found in a router, but much faster than induction motors usually run. That sucker will be spinning like crazy. The VFD would need to put out 313 Hz! It may not even be capable of doing so, not all are.

So you can see a VFD is not the end-all, be-all. I don't recall what gearing I am using (2:3?), but I have given up a little high end RPM in favor of improved low end HP from my 1.5 HP motor.

Another thing to consider, unless you can see the VFD readout, do the math, and make a freq-RPM conversion chart you won't know what RPM your spindle is turning . . . . unless you add a tach like I did.

Am I happy with my installation? Yes, but not 100%. I removed the idler pulley and left the V-belt gearing alone but don't use it. As I said I have sacrificed some high-end RPM in favor of low end HP and convenience. Now, since it is so easy, I keep a chart handy and turn a dial to quickly change speeds all the time- something I rarely if ever did before.

VFD mounted under motor:

http://www.ncwoodworker.net/pp/data/500/DP-8.JPG

Idler pulley removed and replaced with an electrical box for laser and tach power supplies:


http://www.ncwoodworker.net/pp/data/500/DP-9.JPG


Start/Stop provides power to VFD. Red knob is speed pot, small toggle switch is run/stop.

http://www.ncwoodworker.net/pp/data/500/DP-6.JPG

http://www.ncwoodworker.net/pp/data/500/DP-7.JPG