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Flexshaft handpiece fitting problems

Hello All,
Just wanted to detail the problems I have had fitting a #20 and a #15 (hammer) handpiece to my flexshaft. I have an old chrome motor from a Foredom dental outfit, but when I got the dental handpiece off of it, I bought a standard flexshaft and #30 handpiece and that all fit together fine…this was maybe 15 years ago. Last year I bought a #20 knockoff from China and it wouldn’t fit onto the flexshaft sheath… many puzzlements later, I enlarged the sleeve on the handpiece using a cylindrical grinding wheel and the #20 finally fit. A few weeks ago I bought what was supposed to be a #15 hammer handpiece off Ebay. It came in a plastic case marked “Foredom” with a set of instructions from Foredom (apparently), but it wouldn’t fit the sheath either. Having the experience with the other handpiece, I easily figured out I needed to ream out the handpiece hole again. However, after that was done, the ball bearing was too tight. I had to file off some of the bottom of the handpiece to allow the groove in the sheath end to center in the ball bearing hole. Still wouldn’t fit. I loosened the spring around the ball bearing and made the hole in it larger and the handpiece finally snapped into the sheath without heroic effort.

I don’t understand why these things don’t fit out of the box. It took about an hour to fit each of these. I could understand the knock off, $12 purchase price #20 not fitting, but I would have thought that the #15 from Foredom would have fit. Perhaps it too was a knockoff forgery, as it came at about 25% of list. Anyway, I wondered if anyone else has experienced this and wanted others to know you can get cheap handpieces, but there may be some fitting involved in getting them to work on your motor.

Other than the fitting problem, the #20 has worked well the few times I’ve used it and tonight, after relieving the edge on the anvil point and polishing it, it seemed to work OK. The little wrench for the anvil point was missing out of the box, but any little shaft substitutes for that, so no problem there. HTH, royjohn

Over the years, I’ve not had problems with 3 new Foredom handpieces fitting my 20 year old Foredom Flexshaft, but an extra Foredom Chuck Key purchased about 10 years ago did not fit. There’s an unnoticeable but slight difference in the length of the key.

Do manufacturers care about new parts not fitting old machines? It’s time consuming, unprofitable and so easy to call it planned obsolescence. It’s the burden of buying quality when the motor lasts longer than available parts.

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I’ve purchased 2 new complete sheave assemblies in the last 18 months and have an assortment of hand pieces. Not a single problem. Is it possible y’all have received some knockoffs unwittingly? As far as modifying either part to fit seems like returning it might have been an alternative.

I travel quite a bit among studios and schools in the States teaching classes. The flex shaft is always a part of or sometimes the entire subject of a class. I also encounter a wide variety of flex shafts. There is often indeed a problem with knockoff hand pieces not snapping over the end of the sheath —the opening on the handpiece is just not wide enough. I’ve even seen this with a few #30’s marked “Foredom” although they could have been knockoffs.

One thing else that I’ve noticed among newer #30’s—genuine Foredom’s is tgat the jaws don’t open as wide as they used to. I have an old #3O that I travel with that opens to 5mm. Now they seem to barely open to 4.3…

Please excuse any typos-- curse my clumsy digits…

Hi Andy and All,
Thanks, Andy, for the confirmation…I guess I’ll mike the sheath in case it happens to be oversize, but since the original #30 fit fine, I suspect it is undersized sleeves on the handpieces I bought. I wasn’t thrilled with having to modify them, but, all in all, at the prices I paid and the non-heavy duty use (intermittent part time use) I subject them to, I am OK with the small hassle involved. Once I figured out what was wrong (I initially suspected the cable key and the hole it fits into) the fix was about a 30-40 minute gig. I saved $90 on the hammer handpiece, so I’m not complaining. The label on the plastic case was very convincing, so if it’s a knock off, it’s a good one. It would be good for prospective buyers to know what they might be getting into…

Hello “Royjohn” and all the rest of the Ganoksin members that are reading this thread. In my opinion, I think the problem started with “made in China”. As far as the #30 handpiece chucks not being able to open up to 5mm… they did at one time. I know that for a fact that when my company used to make our own #30 handpiece’s we were buying our chucks directly from “Jacobs Chuck Co.” and they all opened up to 5mm. There’s a good chance that the chucks which are not able to open to 5mm, could be “made in China” Do you see the connection? Possibly the cost of the Jacobs #0 chuck became too high so manufacturers went to China to find a cheaper copy & they did. Any company that is making a Flexshaft today is 99+% sure that they are using a chuck from China…so go to Harbor Freight and pick up a couple of extra flexshaft motors, they come complete with rheostats & #30 handpieces… Thank you for listening to me, Regards, Richard Lucas from the Lucas Dental Company, we are the #9 Lowboy Rheostat folks.

Hi Richard. I keep a #30 from back in the day because it opens to just a tad over 5mm. I put all sorts if things in the chuck and use it as a lathe or mini lap. I have noticed two size opening step downs over the years and it is disappointing.

Mike, are you out there?

There was a company that made #30 styles that opened super wide. I can’t recall who it was but when I tried to order one they were out of business. The HP was a powder blue color…

Richard why don’t u start making a wide mouth adjustable HP?


Please excuse any typos-- curse my clumsy digits…

Hello Andy_C, I may consider that… in my next life. :thinking: The only other company out there that made a #30 style handpiece was Pfingst & Company in NJ, Have a pleasant day Andy_C and smell the roses :rose: Regards, Richard Lucas

It also could have been the Emesco Dental Company, that were located in NYC, and then moved out to NJ,…