Problems with our planer/thicknesser

[WAYNE WRX]

Hi all, sorry if this is in the wrong section, we have a problem with our planer/thicknesser and thought that you guys would be able to help with a few questions I have.

The problem is that the threads have gone on the rise and fall table, and so I am trying to replace the part that’s stripped.

Here are a few pictures of what I mean and you will be able to see the part that is stripped.....

The size of the thread is 3/4" 16tpi UNF and roughly 12"/300mm long
Now I presume that the mitre gear would be made from cast and the thread would either be Mild steel of high tensile steel, this is really my question.

Which would be the one to get that wouldn't put any wear on the mitre gear or which one would it have been, mild or high?

The machine was made by the Dodd group which have now disappeared so no good asking them. The machine has given us 25years of trouble free use and is pretty much used every day minus weekends.
I haven’t checked the thread on the mitre gear, I'm hoping that it is ok.

Please guys, your thoughts and idea's would be appreciated,
Wayne

 

[mike os]

first question would be what condition is the thread inside the bevel gear?

 

[WAYNE WRX]

first question would be what condition is the thread inside the bevel gear?

Thanks Mike for getting back to me so quick, Will have to check on that, if I said it was good, which thread would be best for it?
Wayne

 

[mike os]

has to match the nut... but if both are gone then you have the option of remachining the nut to match an off the shelf threaded bar/leadscrew..... not that that is not an option in any case

not sure of teh exact profile of the thread but they tend to be acme type stuff....

 

[awemawson]

Bore out the bevel gear, make up a flanged female thread and loctite it into the bevel gear, replace the male thread. This mewans that you are not limited to the current thread if you wish to go metric for instance.

 

[octo0072000]

just a though if bevel gear thread is usable with a clean up can you not turn the threaded bar upside down bottom half of thread looks unused

 

[ford34/2]

one link worth a try, or if the Bevel gear is ok and you can justify the expense and only need the Bar, Think I would be asking local Eng/Machine shops.

http://www.moore-international.com/rolled_finish_commercial_range_leadscrews.html

This is my local whiz kid, did some shafts with Spines on for me, turning machine anything. should see the stuff he has in for repair,mindblowing
Douglas E Ward (Engineering) Ltd

Address:
Main Building, Double Row
Postcode:
NE25 0PP
City/Town:
Seaton Delaval, Whitley Bay (Tyne And Wear)
Main phone:
0191 2371577

Bit coarse a thread but office chairs, scaffold adjusters???or even consider cutting out the stripped piece and weld the two bits back to gether

 

[Drains]

That looks to me like you might be able to get away with stripping the threaded rod and bevel out of the machine, removing any wayward thread material and putting back together. I know that might sound a bit shonky but it looks like not much of the thread is bu&&ered and if three or four threads are in contact with the bevel at any time it'll probably work ok. You need a thread file to clean it up nicely, although the bevel might need more work if the threads on that are away.

Otherwise if replacement is required, mild steel barscrew will be fine, if the bevel gear is ok. If you're getting something machined up, any machine shop will offer some decent material - doesn't need to be high tensile though. EN1A or plain old bright bar will be fine.

 

[WAYNE WRX]

Ok , thanks everyone who have replied, I know the mitre gear needs looking at, its just at the moment, the machine is needed if only for surfacing.
When I measured the thread with the gauges, its 16tpi in sae and so definitely not acme in this case,
So my options are so far, replace the thread as is, but I don’t know whether to get mild steel or High tensile
If the mitre gear is toast, personally feel and would be easier as we don’t have a lathe, would be to re-drill the gear and put a metric thread into it and obviously use a metric bar, something like a M20.
As I say, the question that’s got me is, do we get normal mild steel or High tensile? Personally I think high tensile but would be nice if someone could confirm
And no I’m afraid the threaded bar can’t be turn end for end as its worn all along it.
Thanks Wayne

 

[WAYNE WRX]

That looks to me like you might be able to get away with stripping the threaded rod and bevel out of the machine, removing any wayward thread material and putting back together. I know that might sound a bit shonky but it looks like not much of the thread is bu&&ered and if three or four threads are in contact with the bevel at any time it'll probably work ok. You need a thread file to clean it up nicely, although the bevel might need more work if the threads on that are away.

Otherwise if replacement is required, mild steel barscrew will be fine, if the bevel gear is ok. If you're getting something machined up, any machine shop will offer some decent material - doesn't need to be high tensile though. EN1A or plain old bright bar will be fine.

Thanks for the reply, well the camera hasn’t done the thread justice, it is really in a bad way, so bad it slipping, in fact it won’t come up any farther.
As for the bar, didn’t realise normal bar would work, thought it would wear out quick. If that’s the case, its time for the gear to come out and have a good look.
Thanks for the time and if anybody have any other thoughts, please do tell

Wayne

 

[ford34/2]

Material supply

if you find both stripped,have a look at the link, nuts with flanges on and bar to suit

Stan

 

[WAYNE WRX]

if you find both stripped,have a look at the link, nuts with flanges on and bar to suit

Stan

Have been looking, good site that one, cheers for that
Wayne

 

[mike os]

replace with similar dia bar & bore out teh gear to take a new nut, will probably need to be pinned/locked rather than just glued.... or you could braze it in

 

[the snooper]

the gear might be hardened steel so it may not be that easy to re thread

 

[mike os]

possibly.... most I have come across with "old" stuff has been cast

 

[awemawson]

If it's like my planer thicknesser, the entire weight of the platform that the wood slides on under the cutter rests on the thread and bevel gear so realistically the force is in one direction only. Hence a flanged nut suitably arranged should be quite satisfactory.

 

[mike os]

If it's like my planer thicknesser, the entire weight of the platform that the wood slides on under the cutter rests on the thread and bevel gear so realistically the force is in one direction only. Hence a flanged nut suitably arranged should be quite satisfactory.

you are quite correct.... i faild to notice that the table does not use the gear as a stop..... and has a decent portion of thread above

 

[johnny7]

Seeing as it's shot somewhat why not try a file on the bar/nut, it will file easily with mild steel, the file will 'skate' if it's treated..

Can't help with telling whether it's cast or simply stock that's been machined though

Apart from if it was cast there will be seams where the mould was closed, they will have been dressed but then you'd see the grinding marks around the joint..

Hope you get the fine old machine back in service quickly


John

 

[Shox Dr]

A bit of a bodge, but from the pics the last couple of inches don't look to be used. If that's the case, cut the thread down, and use the unused portion.

Otherwise the right way IMO would be to fit an ACME threaded bar and nut, machining out the bevel gear to take the nut. Std thread types are not designed to be used as a means of adjustment, that's what ACME is for.