Wednesday, December 8, 2010

Boston Model 17 Sharpener Pictures

These pictures are to help identify whether you have a Boston Model 17 electric pencil sharpener. You can click on any image for an enlarged view.

For starters, note that the brand name on the front cover (this pulls out and is the shaving's tray too...) bears the brand name Hunt Boston.

The length of the unit from the edge of the faceplate / tray is about 7 and 15/16 inches. The width is about 3 and 6/16 inches.

Centered on the back of the unit is a case screw.

On the bottom of the unit should be (unless it fell off or was removed) a label with the model number, serial# and other information.

Note there are two case mounting screws (missing in this photo) in the center also to hold the sharpener case closed and suction cup feet to hold the sharpener still if on a flat surface.

Tuesday, November 30, 2010

Model 17 Gear Close-Ups

Here are some comparisons of a Model 17 replacement gear (green) and an original part (that funky burnt peanut butter color)

Note : You can click on any picture to see an enlarged view

This view is of the 'front' side. The cutter shaft of your sharpener goes into this end of the gear.

This view shows the back side of the gear side-by-side. Note that the replacement is simplified, there are no pegs as on the original, and the back is solid, does not have the cutaway that the forms an edge and hub.

These are made to press fit does not require a clip to secure the gear to the shaft.

The thickness of the replacement gear (edge of front collar to back surface) is an approximate match to the thickness of an original part's (edge of front collar to edge of hub and gear on the back). Pictures are not zoomed to the same size (note to self use a tripod) but the caliper is the same setting on both pictures.

Sunday, October 31, 2010

Model 18 Gear Replacement Instructions

Notice: These directions are for a Model 18 sharpener. Models 19 and 17 are generally replaced the same way - directions for those models will be added too so that the specifics and photos match and cover anything that is different on those types of sharpeners. You can click on any of these photos for a close-up. At any time when you are handling the blade assembly, take measures to protect your hands! (guideline suggestions for this are in step 5)

Step 1 - Set up the sharpener as you would when it is ready to use. Tip it slightly forward and tap on the top of the sharpener a few times. This is to shake pencil shaving into the bin. Remove and dump the bin. Unplug the sharpener (safety first!) and turn it over as shown in the picture. Remove the 3 screws from bottom of the case. Yay! somebody already did this one for me! (heh..ok..that was lame)

Step 2- Remove the bottom cover from the case and put it somewhere safely out of the way. Put the mounting screws in this cover (turn it up with the feet down and use it like a holding tray). If you replaced the shavings bin (as shown in the picture), remove it and set it aside until after the repair is complete. Make sure you keep the screws separate from the housing cover screws (will be removed later). Putting the wrong screws in the wrong place can lead to a loose fit and your sharpner may buck and kick instead of running smoothly.

Step 3 - Lift the sharpener assembly out of the case. The center plate holds the motor on one side (right in figure shown) and the sharpening blade and housing on the other side (shown at left). For this repair, you will NOT be removing or loosening anything from motor assembly.

Step 4 - Remove the screws shown and set them aside so they will not be exchanged with the screws that hold the case cover. Pull the blade housing gently back and let it lay to the side while you swap (or install) the replacement gear.

Step 5 - Here is a front view of the blade housing removed and set t0 the side, wires still connected. In view are the blade assembly and a blade assembly guide. This guide has gear teeth that match the a gear that is part of the sharpening blade assembly.

In this side view, you see the blade gear, the blade assembly guide, and the blade assembly. Again, if you are replacing a gear that has completely broken, you may be removing pieces from inside the case rather than just swapping the gear.

Using a cloth or thick wrapping of paper towel or a work glove (make sure you do something to protect your hand from getting cut by the blade), get a grip on the blade assembly and pull it back to remove it from the sharpener. It may take some force to do this if there is still a gear or portion of the gear intact.

Notice that the shaft on the blade assembly has some flat side sections on it near the end. If you examine the shaft-mount on the gear, you will see that it also has flat portions in the end face that match up with the shaft . This locks the shaft in and keeps it from free-spinning so the gear will drive the blade assembly when it is turned by the motors main drive that engages to this gear.

Step 6 - Do a test fit of the blade assembly to the gear. This step does not take long and will familiarize you with what it takes to get a proper fit and aligment of the parts when they are replaced into the sharpener.

Step 7 - if the blade assembly guide came out when you removed the blade assembly, mount it back to the plate. Notice the proper direction and flush fit to the center plate as shown in the figure.

Step 8 - work the blade assembly shaft partially back into the guide and through the hole in the center plate. Place the replacement gear with it's collar section and shaft mount facing the center plate. Turn the blade assembly and match it up to the shaft mount in the gear's collar, then snap it fully into place. This should align the gear so it meshes with the small drive gear on the motor.

Step 9 - Replace the blade assembly cover back over the blade assembly. Fasten it back to the center plate with the mounting screws. Re-assemble the sharpener by working your way backwards through steps 3, 2, 1 and you should have lift-off!

Wednesday, August 25, 2010

I currently have a listing on ebay for the Model 18 and Model 19 replacement gear. I have had a few requests come in for the Model 17 and will make some available soon.

My assumption has been that if you even know your gear is broken, then you know how to open the sharpener and remove/replace a gear. Even if you are not a Jedi Do It Yourselfer, this is not a tough repair. A photo-guide for this is the next project...

Wednesday, August 11, 2010

Boston Model 17 testing is complete!

Tooling and testing for the Boston Model 17 Pencil Sharpener replacement gear are now complete. Replacements have been tested for fit and functionality, and are now available. I have already posted a listing on ebay for this part. The current listing item# is 130419932867 or try this link:

Clarification on earlier posts - this gear is only for use with the Model 17. The Model 18 replacement part is only interchangeble for use with Model 19.

Wednesday, August 4, 2010

Reports From The Field

I have received back emails (and some have posted as ebay feedback) already from previous auctions. Well okay, there have been a total of two sold and installed so far (not trying to pad the numbers here!). Both have reported that they have their sharpeners working well again.

A question came up - is there any kind of retaining clip for this gear? I have not seen one on any of the sharpeners (Model 17, Model 18, Model 19). All of these depend on a good tight fit, and the repro gears fit in the same manner as originals do.

This gear works with Model 18 and Model 19. Installation guide will be available soon (although most folks who know they have a broken gear have already been under the hood and know hwo to remove/replace). Tooling and testing for the Model 17 replacement will be soon...

Monday, August 2, 2010

News for Boston Model 19 owners

I just received in a Boston Electric Pencil Sharpener - Model 19. My testing shows that the large gear for the Model 18 is a suitable replacement for the model 19! If you have a model 19 with a broken large gear, the replacement that I have available will work. This is a repro of an original part but made from more durable material.

I am now posting these on ebay with a set price, no waiting on bids or auction end time. The auction on the previous post ended with no takers but this item has been listed again.

Note: correction has been made to this post - the Model 18 part can be used to repair a Model 19 sharpener. The replacement for the Model 17 is very different and NOT replacable by this part. My ebay listings also mention which models are compatible with the item being listed. Sorry for any confusion!

Wednesday, July 28, 2010

This is my latest item and it is black (same material, just a different color for sake of variety, the Batman version!). This is my third ebay auction and I have made mods to the listing in hopes to make things go smoother. Here is the link:
I have found a forum that is full of people asking for this part. I have received no feedback from my posts there. Many of the people posting have not registered so I am not able to contact them so I set up this blog in hopes they will find it.
My goal is to continue to provide this for whoever needs it. Models 17 and 19 are still slated for support too. I have noticed that there are 'watchers' on my auctions and that is terrific but I have tried to make the shipping and buy-it-now options very reasonable.
No items will be listed for auction prior to availability for shipping. If anybody has questions or feedback or a special need (i.e. quantity) contact me here or via ebay.

Wednesday, July 21, 2010

Production forecasting

The first auction for a Model 18 gear is going well and there will be more available.

Monday, July 19, 2010

Monday, July 12, 2010

Boston Pencil Sharpener Model 18 Large Gear

If you found this blog then chances are you have a Boston Electric Pencil Sharpener - Model 18, and let me guess, it was working great for years until one day, the large gear broke.

This happened to my Dad. I had no clue why he wanted to repair it...why not just buy a new one? After seeing how sturdy this sharpener was built and what a perfect point it makes, I now 'get' why he doesn't want a newer different one.

I searched for parts and no luck. I did have plenty of luck finding other folks online who are in the same boat. Their large gear is broken too... some have even purchased new sharpeners but would still rather have their Model 18 working again.

I will for now spare the boring details about all the experimentation it has taken (and small investment!) but the bottom line is, I was able to reproduce the gear. The copy is made of tougher material, and I am able to make spares as-needed.

The image shown is a pair of repro gears, arranged to show the front and back details of the part. On the front side of the part (right side of photo), the mounting hole for the shaft is a detailed copy of the original. The gear will fit on to the shaft assembly just as the old one did. On the rear side of the part (shown on left side of photo), the center hub spacer and edge detail match the original.

These are working prototypes and have some minor flashing on the back edge of the gear. That does not affect operation and I am working to elminate that. I am re-working the mold to eliminate air bubbles, but that has been minor and non-critical to operation also. These prototypes are made of stronger material than the original and will be available for about 12 dollars.


The next phase of this project is to continue improvements on the casting process and then work on replacements for Boston Model 17 and Boston Model 19 gears.