Viel modification thoughts

[Ken S]

Several members have indicated that they will be modifying their Viel belt grinders. I hope this brief roadmap of what worked both well and not so well for me may be beneficial. The variable speed modified Viel has been a joy to use, and has exceeded my expectations. However, being honest, I must admit that my path was not the most direct or cost efficient. While my Viel is quite functional, I consider my workmanship a bit clumsy. 

If I was restarting from scratch, I would purchase the bare bones Viel (no motor) and the Penn State variable speed motor. For those who prefer simplicity or are on a tight budget, the bulk of the benefits may be obtained by just mounting the motor to the Viel frame and matching the diameter of the motor shaft and the bore of the Viel pulley. Mounting the motor is within the realm of the home shop. Mating the diameters will require a metal lathe. Neither job should require much shop time. For those who lack experience with metal, having both operations done by a machine shop makes sense. 

Two thoughts regarding Penn State Industries: Sign up for the email list. PSI runs frequent sales. You may well be able to save twenty percent. Also, (I did not know this, nor have I confirmed it), contact PSI and see if your motor can be shipped with the four step pulley removed. I had to fight with a gear puller to remove mine. It was a nuisance.

The motor comes with a 15mm shaft, approximately .590". The bore of the Viel pulley is half inch, approximately .500" Your choice, reduce the diameter of the motor shaft or bore out the pulley. Either way will work. Reducing the shaft seems the popular favorite, perhaps on the dubious possibility of reusing the motor for another application. I followed good traditional advice and had the shaft reduced. In my case, the motor shop also installed a reversing switch. I suspect boring out the pulley may be the  most cost efficient choice.

Regarding mounting the motor, I have not seen it, however, I believe Rupert's bracket for mounting the motor may be the ideal path. The next best path would be to scrape off the plastic from the PSI included bracket. I sawed off the handle, which was not an efficient choice.

I oriented the motor such that the label was centered on top. A better choice would have been to place the two motor brush screws at three and nine o'clock.

I used 12mm Baltic birch plywood for the two sides (7x12") and the cross piece which holds the motor controller. The cross piece is joined with a dado and two #6x1 1/2" screws on each sude. No glue; the entire assembly is easily removable. Four 1 1/2" quarter by twenty thread flat head screws secure the wooden box to the metal frame. I chose the countersunk flat head bolts so that the unit could lay flat on either side.

The cross piece is flush at the top and two inches shorter than the sides. This makes easy storage for the motor cord. This has proved a good design. 

Rather than trying to provide access holes for the brushes, I decided it was just as easy to remove the wooden box, if needed.

I originally planned to use 19mm Bbp, however the extra thickness would have made mounting the motor control difficult.

I used Bbp because I have worked with it before and had a supply on hand. I believe it will go the distance. If not, I can easily replace it. For rougher duty, like regular farmers market professional duty, I think 1/8" aluminum plate like Max uses would be a better choice.

I really like the slower speed. It is quiet and the work stays cool. I have not needed the reversing option. I still like the idea, however, it is something which could easily be added later, if desired.
Once the motor is mounted and the pulley and shaft mated, any further work can be done or postponed. Building the wooden housing allowed me to safely secure the motor control. Transporting the unit is easier now.

In fact, almost anything beyond mounting the motor and connecting the shaft can be done at anytime or not at all. The added housing, wood or metal, offers little real benefit for a stationary set up. I have several plans for my Viel, the delay being budgetary prudence. I plan to add pyroceram to the platen. I plan to add some of the Viel jigs, most notably the drill bit jig. I plan to add a block arrangement to allow a knife to be held flat(level) and have the belt at the bevel angle. I may adapt the Viel to work with Tormek jigs. Beyond that, who knows?

I hope this is useful. I have intentionally not gone into much detail to keep the post reasonably short. Please feel free to ask questions. I am not a guru; constructive criticism is most welcome. As I have stated before, I am indebted to other forum members for guidance in this project.

Ken

[HenryM]

Ken, 

Thank you for the very for the road map write up on the modifications that you are doing to the Viel belt grinder. I've also been modifying, with Rupert's assistance, a Viel to use the variable speed motor from Penn State.      I also feel, like you, that my workmanship has been a bit clumsy as I've been learning as Rupert has been guiding me along the process. 

We decided to reduce the diameter of the shaft of the motor to 0.500". This allows us to use a 3" Viel pulley for a 1:1 ratio. 

I've been working on creating Rupert's bracket using a 4x6 piece of aluminum.     Once the bracket has been perfected, I'll create a template that will make the process much faster and easier. Once mounted on Rupert's bracket, the motor is oriented with the brush screws at the three and nine o'clock position. 

The next step, for now, is modifying the location of one of the bracket mounting screws as it is currently in the way of belt if installed      and installing a reversing switch. I've purchased the reversing switch and would be interested to see how the machine shop that you used installed it and where on the control box.

[Ken S]

Very good post, Henry. I wish I had seen it before starting. The idea of substituting the three inch Viel pulley for the six inch is intriguing. Switching from a six inch to a three inch pulley would reduce the speed of the grinding belt by half, without altering the speed of the motor. I am guessing, however, I think this would produce a substantial increase in torque. This could be quite an advantage for a job involving a lot of stock removal. Using the laser/digital tachometer, I set my speed range from 600 to 2600rpm. The speed control can set the range of the motor to include speeds higher thar 1725 rpm. With a smaller pulley, I would just go with the factory settings. [A safety note: use a plastic screwdriver or piece of wood to adjust the pots to avoid any electrical discharge. I used a whittled down bamboo skewer. Again, with the smaller pulley, I would just go with the factory settings.]

You have presented the first really substantial argument for reducing the shaft diameter.  (although, the three inch pulley could also be bored out to 15mm). I must learn more about this. I like the three inch pulley enough to consider redoing mine.

I notice you have the motor positioned lower and closer to the front. Being closer to the front would keep the motor aligned with the bolts holding the platen. Being mounted lower would compensate for the diameter change with the spring arrangement to keep the top pulley sligned. Clever; I'm impressed!

Lowering the motor position could also lower the need for height with a wooden or metal housing to hold the motor speed control. The photo shows how I placed the motor speed control to provide protective covering for the switches. It also shows the positioning of the reversing switch. I wanted reversing to be convenient, but isolated enough so as not to be accidental. I had also thought of a reversing rocker switch to be substituted for the on-off switch. I suspect the motor shop technician chose the course of least resistance. That turned out to be what I wanted. I can see where some might prefer the three position rocker switch.

Reducing the height of the wooden enclosure would reduce the weight and lower the center of gravity somewhat. In theory, both of these would be desirable. In actual operation, I don't see where the difference would matter. If the height was kept the same, there would be room to stow an extension cord on board, a potential plus for a mobile sharpener. 

To redo or not to redo? At the very least, I will print out your template. An enterprising machinist could set up and make several templates with instructions and offer them for sale.........

I assume the Viel three inch pulley is the same part used for the smaller 1x30 model which attaches to a grinder? Also, that it comes predrilled and tapped for the holding Allen screw?

I noted that you have incorporated Rupert's idea of substituting plastic knobs for the small tracking screws (with two washers on each side to compensate for the half inch thread length). I have not needed to fiddle with tracking, however, the knobs seem a good idea and I purchased them from the hardware store. They use a 10-24 thread size.

This post is already too long. I look forward to reading more of your updates, Henry.

Ken

[Rupert Lucius]

Ken,

As you read My Opinion

You, are so perspective and spot on in all dimensions.

For knife sharpening (home, church kitchens, school kitchens, farmers markets and etc.) there may not be a more convenient package than the Viel/Penn combo.

The Viel/Penn, using a 12V battery with inverter is so efficient that it will work all day (6/8 hours).

The Viel/Penn, excellent machine for doing groomer, tailor, upholstery, household shears and etc. with simple and ready made attachments.

Most attachments are usually in 1/2" bore, that is enough to justify 1/2" shaft if additional items are contemplated.  Have the shaft turned to 0.497" and you have a slip fit. 

Also grind a shallow flat into the shaft (create something like a D shaft) this prevents having problems when removing attachment set screw created "burrs" that keep the attachment from sliding off shaft.

Often NOT considered -  NOT to be overlooked  -  the Viel belt runs in front of the upright post  supporting the idler wheel.  With the Kalamazoo SM 1 belt runs "off center" to the right of idler support post -  impossible to modify for a scissor sharpening machine - TRUST!  several of us sharpeners have tried.  We have tried and tried!  The SM 1 is perfect for the mission it was designed to accomplish, perfect and so affordable nothing better.

Difficult to beat the Viel/Penn combo, I, do not know where or if that machine exist.  Sorby's machine is the closest (my opinion) somewhere far behind in the dust.  Lacking versatility is what kills most of the machines, again my opinion.

Mr. Allen Poe has a sturdy well designed machine: http://amktactical.com/AMK-75-1x30-Knife-Sharpener limited in versatility, excellent for knives as good as it gets.

Viel/Penn combo for what it is - is as good for its purpose as Edge Pal's Chef is in the manual classification - nothing comes close (my opinion) to having the accuracy that Thomas's Edge Pal Chef offers, nothing.

Our moderator Mark will be doing the Sturgis event in early August (10 days?).  If all works he will be doing his final sharpening step on a Viel/Penn combo running leather using a 3.75" drive wheel.

Another plus for the 1/2" shaft, there is about 1" stub +/- sticking outside from the belt drive wheel why not utilize it? http://www.caswellplating.com/buffing-po...shaft.html 

Note: there are right or left hand adapters.

Now install a wheel - may have to block the Viel base up 2" +/- a piece of dimension lumber?

https://www.woodcraft.com/products/buffi...6582000b71  Rupert's secret weapon.

These switches are worth the money 13.99$ MOMENTARY or MAINTAINED: https://www.harborfreight.com/power-main...96618.html

[HenryM]

Yes, the motor is listed at 1700rpm so dropping from a six inch to a three inch Viel pulley should drop the SFM from 2670 to 1335. Hopefully, I can test the rpm on Monday to see the actual SFM range of the motor with the variability. I don't plan on changing the factoring settings. 

You have me thinking about how I can measure the increase in torque, but my guess would be that the torque should double since, if I remember right, speed and torque are the inverse of each other. Hopefully, someone can chime in on this. I've used one of Rupert's belt grinders that also runs at 1700rpm and it has no problems removing stock. 

Yes, you noticed correctly. The motor is mounted lower and closer to the front to help compensate for the change in diameter. I did have to increase the height of arm by adding spacers below the spring. Yes, Rupert showed me the knurled knobs that I needed to replace the tracking screws. Now adjustment does not require any tool. They were 10-24 x 7/8 and we got them at the local hardware store.

[Ken S]

Rupert, a most thoughtful post, and one which reflects an experienced and deep thinking artisan.

Your thoughts on the ideal shaft diameter, .497", with a D flat, are spot on. I was disappointed with the machining done by the motor shop. The Viel pulley fits on the reduced shaft, however, my fit is a bit tight for a slip fit. The finish is rougher than I would expect from a machinist, and the flat is just a hint of a flat compared with the original motor. I dealt with an established company. I would not be a repeat customer. (I hope this candid reporting may help others on our forum.)

Running the Viel/Penn combo with 12volts. Clever;that never occurred to me. That sounds like just the ticket for mobile sharpeners.

I think pairing the Viel with my Tormek will let me use each for its best uses. The Tormek excels with tools like chisels. People do sharpen axes with it, however, I think the Viel is the natural choice for convex edges.

I enjoy your thoughts, Rupert.

Henry, I think your Viel is the best thing going at this point. Hopefully others will join in the quest and continue pushing back the frontier. Your addition of the smaller wheel will add significantly to the machine's torque, which might be a significant factor fot knife makers.

Using standard and Scotch-Brite belts, I have not needed to adjust tracking. This may change as I start using leather belts. The no tool knobs seem very convenient.

I look forward to future posts.

Ken

ps Rupert, I would like to learn more about "Rupert's Secret Weapon". I have just started to try an eight inch by one inch hard felt wheel on my Tormek T4. No conclusions yet.

[Rupert Lucius]

In ref to "magic buff"

Our Moderator looked at one of my edges after the magic buff and he said that the most that I had created was a straightened burr he used 10x magnification for observation purposes.

For what ever reason I continue to "straighten my burrs".  It improves my edges Bess 40 +/- (no compound) (no nothing) (edge improvement?).

Rupert

[Ken S]

When Columbus returned to Spain, the Royal Moderator might have informed him that he has merely discovered another island.

Ken

[Ken S]

Viel modifications are starting to seem like iPad models. I barely have Generation II working, and, already, Generation III is a definite go. My Viel Generation I was the factory model with the quarter horse power motor. It was a versatile tool which served me well. Then came Maxtheknife and the possibility of a variable speed motor and Generation II. Gen II was a game changer, adding the benefits of cooler, more controllable slower speed. I thought Gen II was the ultimate Viel.

Enter Rupert and substituting a smaller diameter Viel pulley. Suddenly Generation II is becoming yesterday's news. Gen II added sllower speed; Gen III will add greater torque with the same variable speed motor. My gut feeling is that Gen III will be as substantial improvement as Gen II. Gen III will be debuting soon.

At this point my advice to those interested in a modified Viel is to be patient until Gen III debuts. In the meantime, sign up for the Penn State Industries email list. While you are waiting for Gen III, PSI may have a good sale.

Ken

[HenryM]

Ken,

That's great advice. Those that haven't started should wait until Generation III debuts. I plan on writing a more detailed post once Generation III is ready. The pictures from the previous post show the work that we have completed so far.