Found damage with my vari drive :-( Need advice.

[D.sebens]

I got my new to me Hartford's VFD set up and spun it up. Sounded real bad, suspected a belt issue. I started taking it apart and found half the teeth missing on the drive belt. The teeth fell down and caused the timing belt to snap.


Motor drive pulley was stuck open, I was able to tap it down but there was issues. I took it apart and found that the moving pulley's key shaft is worn and bell mouthed. This clone uses a seperate clutch shaft that slides on to the motor. It doesnt look like the h&w parts diagram. I've taken measurements of everything but am afraid I might not have suitable replacement parts. Whats the general thought about welding up the shaft keyway and re-milling it? I could turn it down to size on my lathe and I think I could get the highschool to mill it for me.



Next problem, the large timing gear had a belt guide flange screwed to the bottom that broke from the belt carnage. It doesnt look to exist on a bport. I could make this on my lathe but do I even need to?



I have a small crack on the moving pulley on the driven pulley. It's towards the top. This goes back to the thought that I dont know if a bport one would fit. Any tips on fixing(keep in mind I dont have a "running" mill). What about leaving it? That sounds bad but this thing will be living the easy life when I get it running and I dont know how severe that is.


It was missing the large bull gear cover. Again this looks different than the bport one. But I could make one out of sheet gauge steel if needed.


The parts list is like $650 if the parts even fit.

Looking for advice on what to do? I plan on calling H&W Monday to see what they advise. I've heard about swapping over to a single belt ratio, any information about that? What would be needed to do that?

 

[rodm1]

That sucks would a direct drive DC motor work and just totally replace it all?

 

[woodchucker]

That sucks would a direct drive DC motor work and just totally replace it all?

Why would he do that when he's got a vfd?

 

[markba633csi]

I would reweld the keyway and remill it. That's the way to go on these things- if the parts aren't available make 'em.
Vari-speed heads do get abused and are somewhat high-wear mechanisms

 

[MyLilMule]

Welding and machining that keyway should be fine. The problem are those other parts. If it's cracked, replace it. You're only asking for future problems if you don't.

Besides Barry @ H&W, you can also try calling Tim at Besmer Machine. He's as good as any with Bridgeports and probably the clones, too. You can find him on Facebook. The other person I would try is Mike @ Lee's Machinery in Ohio. Mike has a warehouse full of old machines and parts. There's a chance he may have some of those parts somewhere. I've dealt with all three and all three have been awesome to work with.

 

[D.sebens]

Well baby steps were made. I made the timing belt retention plate thing. I’ve got to be the only fool with a bport clone and a 7x12 lathe. I had to strategize how I would make the part. Its about 6.5” in diameter. I ended up using the faceplate and through bolting it. I need to caress the screw holes a little bigger, my eyeballing was a little off.

 

[ericc]

I think that a welding repair is appropriate. If you send it in, that's what will happen anyway, for the next recipient in line. As for the cracks, my mill came with cracks. I just put in plates, screws and JB weld. I finally got another pulley, but the repair is still holding.

 

[D.sebens]

Made some progress on the motor shaft thing. There’s uneven wear and it’s a little non concentric. I don’t know how much that matters since it will be a plastic bushing. It probably warped a little with welding. Overall I think it looks passable.

I got to thinking the deal that got me this machine came with a horizontal mill with a key slot cutter installed. Ironically I have a machine to slot a keyway! I wired it up to my vfd and it runs!

I don’t have a real Vice but I do have a junky drill press Vice I bolted to it and trammed. I figure it’s probably more accurate than beating it with rocks until a keyway appears.

Hopefully I’ll be able to cut it today. I also don’t have a beveled edge to hold round objects tighter. It seems to clamp okay, I’m hoping it won’t pull it out.

 

[markba633csi]

Use wood pieces to grip the part in the vise- they squish around it and hold better than just the vise jaws alone
-Mark

 

[D.sebens]

For the motor pulley with the wollered keyway would braze hold up the the use? I could weld but that will input a lot more heat and be harder to machine out. If I use braze I could just use a square file to clean up the key way. I know I could theoretically do the same with weld but it’s going to be a tight hole and suspect the weld is going to make a mess in the hole and be harder to file.

If welding is the route I need to take I was thinking about using the lathe carriage for slotting the keyway. I’ve never done that operation before though. It’s also kind of a long section to slot and feel like I might get some deflection on the hss blank.

Its hard to tell from the picture but the keyway is pretty bad and the shoulders are far from 90*

Edited to add reference picture to the pulley in question