Helicoil and blade raising thread

[woodturner]

Thanks, everyone, for your comments and suggestions. I think I will go with the heli-coil, for the reasons mentioned. I had envisioned using a dial indicator to square and center the drill, but the drill method solution will be so much easier.

Thanks again for all your help!!

[Tom Slick]

I've used heli-coils, Time-serts, and E-Z locks quite a bit. The problem with an E-Z lock is for a 9/16-12 insert you have to drill and tap a 3/4-10 hole. Is there enough material in the boss for a 3/4" hole? The other problem is a 3/4-10 tap is going to cost $40+ and another 10 for the insert pack vs $30 for an Heli-coil full kit.

[All Thumbs]

I went through this several years ago. I would go with the helicoil first or something similar. helicoil does trade on its name but the patents have long since expired and there are copycats that work. Reason is that if it fails, or you screw it up (it's possible trust me), there is still one more shot with at keensert (or equivalent). Admittedly all this gets expensive and increasingly frustrating

I strongly suggest pulling the whole mess out of the saw and setting it up on a drill press to do the new tap drill. Chances of success the first time are greatly improved.

Correct procedure is to find the largest bit you have that fits in current botched threads smoothly but not too much play. Chuck the bit in the press and with motor off feet the bit into the hole you need to re-drill. Once the bit is holding the workpiece in position, clamp the workpiece so it can't move.

Now, retract the setup bit and install the working bit in the chuck. When you drill the hole, it will be perfect.

Or just give it to a machinist or engineering tech and let them do it.

[Skaning]

I may try the E-z lock, since the part is less than $2 and installation does not require special tools. The heli-coil kit is available in the range of $30.

I went through this several years ago. I would go with the helicoil first or something similar. helicoil does trade on its name but the patents have long since expired and there are copycats that work. Reason is that if it fails, or you screw it up (it's possible trust me), there is still one more shot with at keensert (or equivalent). Admittedly all this gets expensive and increasingly frustrating

I strongly suggest pulling the whole mess out of the saw and setting it up on a drill press to do the new tap drill. Chances of success the first time are greatly improved.

[woodturner]

Anyone have any experience with E-z lok with BT3k? BTW, unless I'm missing something, a Heli-coil kit isn't outrageously more expensive: toolsource.com has a kit for 39.70.

I may try the E-z lock, since the part is less than $2 and installation does not require special tools. The heli-coil kit is available in the range of $30.

[woodturner]

When this happened to my bt3100, the easier and cheaper solution was to replace the part.

It's only available as the motor assembly at $200. However, the dealer that sold me the saw did get Ryobi to send just the part, but it was the right part number but a similar but different part. It appears the part for this vintage is no longer available, and no guarantees the one on the motor assembly is the right part, either.

[mnmphd]

When this happened to my bt3100, the easier and cheaper solution was to replace the part. I am pretty sure it was less $30. I had to swap the bearing/pully assembly but I figured that was less prone to error than
boring/tapping/inserting the helicoil. That said, I kept the older motor bracket
in case I ever got easy access to a helicoil kit.

[jdon]

The e-z lok looks like an interesting alternative to Heli-coil - cheaper (quick web check:~$10 for 5). Only potential drawbacks I see are:

1) fewer threads (shorter insert: .656 vs .844 in. for H-C)

2) slightly larger drill out (21/32 vs. 19/32).

Anyone have any experience with E-z lok with BT3k? BTW, unless I'm missing something, a Heli-coil kit isn't outrageously more expensive: toolsource.com has a kit for 39.70.

I'm trying to avoid needing such a repair, but always good to have the knowledge available.

[jeepman71]

http://www.ezlok.com/InsertsMetal/installation.html

This is a product that we used at Ford motor rebuilders in the 80s. I believe if memory serves that the tap size is a normal size.

Jeepman71

[JimD]

I thought I needed a helicoil once but it was just that the height mechanism needed lubricated and the plastic handle was turning on the steel shaft. Probably that isn't your problem but I thought I would mention it. Mine is a BT3100 and I think it would be pretty hard to strip the threads using the plastic handle.

Jim

[Black wallnut]

I would steer away from the linked threadsert as it appears from the product description that it has locking threads. It also does not say what material it is made from. Heli-coil is stainless and is a proven solution to this problem. The only hard part is making sure that you drill straight, and then making sure your tap follows straight. Once you do this apply a bit of locTite to the threads (external) when you install the insert.

[woodturner]

Possibly a threadsert would work. I believe they use two sizes up as far a tap sizes. Been too long since I have used these. Here is some information.
http://www.timesert.com/

That does look like a better solution, but the kits are rather expensive (~$120).

I'll ask around and check to see if they are available as loaner tools anywhere.

[jeepman71]

Possibly a threadsert would work. I believe they use two sizes up as far a tap sizes. Been too long since I have used these. Here is some information.
http://www.timesert.com/

Jeepman71

[Stytooner]

Before buying, you might check with an auto parts store. Our Advance Auto will rent odd tools out cheaply.

[woodturner]

as far as I know, the 9/16-12 is common to all BT3 variants.

OK, thanks. The guy I bought the saw from turned out to be the owner of a local sharpening and machinery sales and repair dealer. He had taken it in trade, ordered a replacement part from Ryobi, with the right part number, but the one they sent him was not the right part. IIRC, the one they sent had square corners on the casting, while the one on the saw has rounded corners. He said it was close but didn't quite fit.

I'll check the threaded rod before starting the repair, just to make certain.

We did have a floating kit but it was lost when someone broke the chain.

I'm going to check with the ME department to see if they might have a set. If not, I guess I will have to buy one. In that event, maybe we can try the floating kit idea another try.

Thanks.